Gastroenterology

LIVERPOOL, ENGLAND — The British Society for Rheumatology (BSR) and the British Association of Dermatologists (BAD) have joined forces for the first time to develop the first British guidelines for the management of people living with Behçet’s disease.

The guidelines will also be the first “living guidelines” produced by either society, which means they will be regularly revised and updated when new evidence emerges that warrants inclusion.

With more than 90 recommendations being made, the new guidelines promise to be the most comprehensive and most up-to-date yet for what is regarded as a rare disease. Robert Moots, MBBS, PhD, provided a “sneak peek” of the guidelines at the annual meeting of the British Society for Rheumatology.

Dr. Moots, professor of rheumatology at the University of Liverpool and a consultant rheumatologist for Liverpool University Hospitals NHS Foundation Trust in England, noted that while the European Alliance of Associations for Rheumatology has produced a guideline for Behçet’s disease, this was last updated in 2018 and is not specific for the population for patients that is seen in the United Kingdom.

The British recommendations will cover all possible manifestations of Behçet’s disease and give practical advice on how to manage everything from the most common presentations such as skin lesions, mouth ulcers, and genital ulcers, as well as the potentially more serious eye, neurological, and vascular involvement.

167862_Moots_Robert_web.jpg

Importance of Raising Awareness

“Joint and musculoskeletal problems are actually one of the least complained of symptoms in people with Behçet’s, and they often can’t understand why a rheumatologist is seeing them,” Dr. Moot said. “But of course, people do get joint problems, they can get enthesitis and arthralgia.”

Dr. Moots has been leading one of the three National Health Service (NHS) Centres of Excellence for Behçet’s Syndrome in England for more than a decade and told this news organization that diagnosing patients could be challenging. It can take up to 10 years from the first symptoms appearing to getting a diagnosis, so part of the job of the NHS Centres of Excellence is to raise awareness among both the healthcare profession and the general public.

“It’s a condition that people learn about at medical school. Most doctors will have come across it, but because it was thought to be really rare in the UK, nobody perhaps really expects to see it,” Dr. Moot said.

“But we all have these patients,” he added. “In Liverpool, we’re commissioned to be looking after an anticipated 150 people with Behçet’s — we’ve got 700. With more awareness, there’s more diagnoses being made, and people are being looked after better.”
 

Patient Perspective

Tony Thornburn, OBE, chair of the patient advocacy group Behçet’s UK, agreed in a separate interview that raising awareness of the syndrome was key to improving its management.

“Patients have said that it is a bit like having arthritis, lupus, MS [multiple sclerosis], and Crohn’s [disease] all at once,” Mr. Thorburn said. “So what we need is a guideline to ensure that people know what they’re looking at.”

Mr. Thorburn added, “Guidelines are important for raising awareness but also providing the detailed information that clinicians and GPs [general practitioners] need to have to treat a patient when they come in with this multifaceted condition.”
 

Multifaceted Means Multidisciplinary Management

Because there can be so many different aspects to managing someone with Behçet’s disease, a multispecialty team that was convened to develop the guidelines agreed that multidisciplinary management should be an overarching theme.

“The guideline development group consisted of all the specialties that you would need for a complex multisystem disease like Behçet’s,” Dr. Moot said. He highlighted that working alongside the consultants in adult and pediatric rheumatology were specialists in dermatology, gastroenterology, neurology, ophthalmology, obstetrics and gynecology, and psychology.

“We’re actually looking at psychological interactions and their impact for the first time,” Dr. Moot said, noting that clinicians needed to “take it seriously, and ask about it.”
 

Management of Manifestations

One of the general principles of the guidelines is to assess the involvement of each organ system and target treatment accordingly.

“One of the problems is that the evidence base to tell us what to do is pretty low,” Dr. Moots acknowledged. There have been few good quality randomized trials, so “treatment tends to be eminence-based rather than evidence-based.”

The recommendation wording bears this in mind, stating whether a treatment should or should not be offered, or just considered if there is no strong evidence to back up its use.

With regard to musculoskeletal manifestations, the recommendations say that colchicine should be offered, perhaps as a first-line option, or an intraarticular steroid injection in the case of monoarthritis. An intramuscular depot steroid may also be appropriate to offer, and there was good evidence to offer azathioprine or, as an alternative in refractory cases, a tumor necrosis factor (TNF) inhibitor. Nonsteroidal anti-inflammatory drugs, methotrexate, apremilast, secukinumab, and referral to a physiotherapist could only be considered, however, based on weaker levels of evidence for their use.

To treat mucocutaneous disease, the guidelines advise offering topical steroids in the form of ointment for genital ulcers or mouthwash or ointment for oral ulcers. For skin lesions, it is recommended to offer colchicine, azathioprine, mycophenolate mofetil, or TNF inhibitor and to consider the use of apremilast, secukinumab, or dapsone.
 

Future Work and Revision

“One of the key things we would like to see developing is a national registry,” Dr. Moots said. This would include biobanking samples for future research and possible genomic and phenotyping studies.

More work needs to be done in conducting clinical trials in children and young people with Behçet’s disease, studies to find prognostic factors for neurological disease, and clinical trials of potential new drug approaches such as Janus kinase inhibitors. Importantly, an auditing process needs to be set up to see what effect, if any, the guidelines will actually have onpatient management.

“It’s taken 5 years to today” to develop the guidelines, Dr. Moot said. What form the process of updating them will take still has to be decided, he said in the interview. It is likely that the necessary literature searches will be performed every 6 months or so, but it will be a compromise between the ideal situation and having the staffing time to do it.

“It’s a big ask,” Dr. Moot acknowledged, adding that even if updates were only once a year, it would still be much faster than the 5- or 6-year cycle that it traditionally takes for most guidelines to be updated.

The BSR and BAD’s processes for developing guidelines are accredited by the National Institute for Health and Care Excellence in England. Dr. Moots is the chief investigator for the Secukinumab in Behçet’s trial, which is sponsored by the Liverpool University Hospitals NHS Foundation Trust via grant funding from Novartis.
 

A version of this article appeared on Medscape.com.

LIVERPOOL, ENGLAND — The British Society for Rheumatology (BSR) and the British Association of Dermatologists (BAD) have joined forces for the first time to develop the first British guidelines for the management of people living with Behçet’s disease.

The guidelines will also be the first “living guidelines” produced by either society, which means they will be regularly revised and updated when new evidence emerges that warrants inclusion.

With more than 90 recommendations being made, the new guidelines promise to be the most comprehensive and most up-to-date yet for what is regarded as a rare disease. Robert Moots, MBBS, PhD, provided a “sneak peek” of the guidelines at the annual meeting of the British Society for Rheumatology.

Dr. Moots, professor of rheumatology at the University of Liverpool and a consultant rheumatologist for Liverpool University Hospitals NHS Foundation Trust in England, noted that while the European Alliance of Associations for Rheumatology has produced a guideline for Behçet’s disease, this was last updated in 2018 and is not specific for the population for patients that is seen in the United Kingdom.

The British recommendations will cover all possible manifestations of Behçet’s disease and give practical advice on how to manage everything from the most common presentations such as skin lesions, mouth ulcers, and genital ulcers, as well as the potentially more serious eye, neurological, and vascular involvement.

167862_Moots_Robert_web.jpg

Importance of Raising Awareness

“Joint and musculoskeletal problems are actually one of the least complained of symptoms in people with Behçet’s, and they often can’t understand why a rheumatologist is seeing them,” Dr. Moot said. “But of course, people do get joint problems, they can get enthesitis and arthralgia.”

Dr. Moots has been leading one of the three National Health Service (NHS) Centres of Excellence for Behçet’s Syndrome in England for more than a decade and told this news organization that diagnosing patients could be challenging. It can take up to 10 years from the first symptoms appearing to getting a diagnosis, so part of the job of the NHS Centres of Excellence is to raise awareness among both the healthcare profession and the general public.

“It’s a condition that people learn about at medical school. Most doctors will have come across it, but because it was thought to be really rare in the UK, nobody perhaps really expects to see it,” Dr. Moot said.

“But we all have these patients,” he added. “In Liverpool, we’re commissioned to be looking after an anticipated 150 people with Behçet’s — we’ve got 700. With more awareness, there’s more diagnoses being made, and people are being looked after better.”
 

Patient Perspective

Tony Thornburn, OBE, chair of the patient advocacy group Behçet’s UK, agreed in a separate interview that raising awareness of the syndrome was key to improving its management.

“Patients have said that it is a bit like having arthritis, lupus, MS [multiple sclerosis], and Crohn’s [disease] all at once,” Mr. Thorburn said. “So what we need is a guideline to ensure that people know what they’re looking at.”

Mr. Thorburn added, “Guidelines are important for raising awareness but also providing the detailed information that clinicians and GPs [general practitioners] need to have to treat a patient when they come in with this multifaceted condition.”
 

Multifaceted Means Multidisciplinary Management

Because there can be so many different aspects to managing someone with Behçet’s disease, a multispecialty team that was convened to develop the guidelines agreed that multidisciplinary management should be an overarching theme.

“The guideline development group consisted of all the specialties that you would need for a complex multisystem disease like Behçet’s,” Dr. Moot said. He highlighted that working alongside the consultants in adult and pediatric rheumatology were specialists in dermatology, gastroenterology, neurology, ophthalmology, obstetrics and gynecology, and psychology.

“We’re actually looking at psychological interactions and their impact for the first time,” Dr. Moot said, noting that clinicians needed to “take it seriously, and ask about it.”
 

Management of Manifestations

One of the general principles of the guidelines is to assess the involvement of each organ system and target treatment accordingly.

“One of the problems is that the evidence base to tell us what to do is pretty low,” Dr. Moots acknowledged. There have been few good quality randomized trials, so “treatment tends to be eminence-based rather than evidence-based.”

The recommendation wording bears this in mind, stating whether a treatment should or should not be offered, or just considered if there is no strong evidence to back up its use.

With regard to musculoskeletal manifestations, the recommendations say that colchicine should be offered, perhaps as a first-line option, or an intraarticular steroid injection in the case of monoarthritis. An intramuscular depot steroid may also be appropriate to offer, and there was good evidence to offer azathioprine or, as an alternative in refractory cases, a tumor necrosis factor (TNF) inhibitor. Nonsteroidal anti-inflammatory drugs, methotrexate, apremilast, secukinumab, and referral to a physiotherapist could only be considered, however, based on weaker levels of evidence for their use.

To treat mucocutaneous disease, the guidelines advise offering topical steroids in the form of ointment for genital ulcers or mouthwash or ointment for oral ulcers. For skin lesions, it is recommended to offer colchicine, azathioprine, mycophenolate mofetil, or TNF inhibitor and to consider the use of apremilast, secukinumab, or dapsone.
 

Future Work and Revision

“One of the key things we would like to see developing is a national registry,” Dr. Moots said. This would include biobanking samples for future research and possible genomic and phenotyping studies.

More work needs to be done in conducting clinical trials in children and young people with Behçet’s disease, studies to find prognostic factors for neurological disease, and clinical trials of potential new drug approaches such as Janus kinase inhibitors. Importantly, an auditing process needs to be set up to see what effect, if any, the guidelines will actually have onpatient management.

“It’s taken 5 years to today” to develop the guidelines, Dr. Moot said. What form the process of updating them will take still has to be decided, he said in the interview. It is likely that the necessary literature searches will be performed every 6 months or so, but it will be a compromise between the ideal situation and having the staffing time to do it.

“It’s a big ask,” Dr. Moot acknowledged, adding that even if updates were only once a year, it would still be much faster than the 5- or 6-year cycle that it traditionally takes for most guidelines to be updated.

The BSR and BAD’s processes for developing guidelines are accredited by the National Institute for Health and Care Excellence in England. Dr. Moots is the chief investigator for the Secukinumab in Behçet’s trial, which is sponsored by the Liverpool University Hospitals NHS Foundation Trust via grant funding from Novartis.
 

A version of this article appeared on Medscape.com.

LIVERPOOL, ENGLAND — The British Society for Rheumatology (BSR) and the British Association of Dermatologists (BAD) have joined forces for the first time to develop the first British guidelines for the management of people living with Behçet’s disease.

The guidelines will also be the first “living guidelines” produced by either society, which means they will be regularly revised and updated when new evidence emerges that warrants inclusion.

With more than 90 recommendations being made, the new guidelines promise to be the most comprehensive and most up-to-date yet for what is regarded as a rare disease. Robert Moots, MBBS, PhD, provided a “sneak peek” of the guidelines at the annual meeting of the British Society for Rheumatology.

Dr. Moots, professor of rheumatology at the University of Liverpool and a consultant rheumatologist for Liverpool University Hospitals NHS Foundation Trust in England, noted that while the European Alliance of Associations for Rheumatology has produced a guideline for Behçet’s disease, this was last updated in 2018 and is not specific for the population for patients that is seen in the United Kingdom.

The British recommendations will cover all possible manifestations of Behçet’s disease and give practical advice on how to manage everything from the most common presentations such as skin lesions, mouth ulcers, and genital ulcers, as well as the potentially more serious eye, neurological, and vascular involvement.

167862_Moots_Robert_web.jpg

Importance of Raising Awareness

“Joint and musculoskeletal problems are actually one of the least complained of symptoms in people with Behçet’s, and they often can’t understand why a rheumatologist is seeing them,” Dr. Moot said. “But of course, people do get joint problems, they can get enthesitis and arthralgia.”

Dr. Moots has been leading one of the three National Health Service (NHS) Centres of Excellence for Behçet’s Syndrome in England for more than a decade and told this news organization that diagnosing patients could be challenging. It can take up to 10 years from the first symptoms appearing to getting a diagnosis, so part of the job of the NHS Centres of Excellence is to raise awareness among both the healthcare profession and the general public.

“It’s a condition that people learn about at medical school. Most doctors will have come across it, but because it was thought to be really rare in the UK, nobody perhaps really expects to see it,” Dr. Moot said.

“But we all have these patients,” he added. “In Liverpool, we’re commissioned to be looking after an anticipated 150 people with Behçet’s — we’ve got 700. With more awareness, there’s more diagnoses being made, and people are being looked after better.”
 

Patient Perspective

Tony Thornburn, OBE, chair of the patient advocacy group Behçet’s UK, agreed in a separate interview that raising awareness of the syndrome was key to improving its management.

“Patients have said that it is a bit like having arthritis, lupus, MS [multiple sclerosis], and Crohn’s [disease] all at once,” Mr. Thorburn said. “So what we need is a guideline to ensure that people know what they’re looking at.”

Mr. Thorburn added, “Guidelines are important for raising awareness but also providing the detailed information that clinicians and GPs [general practitioners] need to have to treat a patient when they come in with this multifaceted condition.”
 

Multifaceted Means Multidisciplinary Management

Because there can be so many different aspects to managing someone with Behçet’s disease, a multispecialty team that was convened to develop the guidelines agreed that multidisciplinary management should be an overarching theme.

“The guideline development group consisted of all the specialties that you would need for a complex multisystem disease like Behçet’s,” Dr. Moot said. He highlighted that working alongside the consultants in adult and pediatric rheumatology were specialists in dermatology, gastroenterology, neurology, ophthalmology, obstetrics and gynecology, and psychology.

“We’re actually looking at psychological interactions and their impact for the first time,” Dr. Moot said, noting that clinicians needed to “take it seriously, and ask about it.”
 

Management of Manifestations

One of the general principles of the guidelines is to assess the involvement of each organ system and target treatment accordingly.

“One of the problems is that the evidence base to tell us what to do is pretty low,” Dr. Moots acknowledged. There have been few good quality randomized trials, so “treatment tends to be eminence-based rather than evidence-based.”

The recommendation wording bears this in mind, stating whether a treatment should or should not be offered, or just considered if there is no strong evidence to back up its use.

With regard to musculoskeletal manifestations, the recommendations say that colchicine should be offered, perhaps as a first-line option, or an intraarticular steroid injection in the case of monoarthritis. An intramuscular depot steroid may also be appropriate to offer, and there was good evidence to offer azathioprine or, as an alternative in refractory cases, a tumor necrosis factor (TNF) inhibitor. Nonsteroidal anti-inflammatory drugs, methotrexate, apremilast, secukinumab, and referral to a physiotherapist could only be considered, however, based on weaker levels of evidence for their use.

To treat mucocutaneous disease, the guidelines advise offering topical steroids in the form of ointment for genital ulcers or mouthwash or ointment for oral ulcers. For skin lesions, it is recommended to offer colchicine, azathioprine, mycophenolate mofetil, or TNF inhibitor and to consider the use of apremilast, secukinumab, or dapsone.
 

Future Work and Revision

“One of the key things we would like to see developing is a national registry,” Dr. Moots said. This would include biobanking samples for future research and possible genomic and phenotyping studies.

More work needs to be done in conducting clinical trials in children and young people with Behçet’s disease, studies to find prognostic factors for neurological disease, and clinical trials of potential new drug approaches such as Janus kinase inhibitors. Importantly, an auditing process needs to be set up to see what effect, if any, the guidelines will actually have onpatient management.

“It’s taken 5 years to today” to develop the guidelines, Dr. Moot said. What form the process of updating them will take still has to be decided, he said in the interview. It is likely that the necessary literature searches will be performed every 6 months or so, but it will be a compromise between the ideal situation and having the staffing time to do it.

“It’s a big ask,” Dr. Moot acknowledged, adding that even if updates were only once a year, it would still be much faster than the 5- or 6-year cycle that it traditionally takes for most guidelines to be updated.

The BSR and BAD’s processes for developing guidelines are accredited by the National Institute for Health and Care Excellence in England. Dr. Moots is the chief investigator for the Secukinumab in Behçet’s trial, which is sponsored by the Liverpool University Hospitals NHS Foundation Trust via grant funding from Novartis.
 

A version of this article appeared on Medscape.com.

New and evolving research in locally advanced rectal cancer suggests that selective use of treatments in some patients can achieve outcomes similar to those of standard regimens, according to the chair of the Department of Radiation Oncology at Duke University School of Medicine, Durham, North Carolina.

Total neoadjuvant therapy (TNT) is the standard treatment that involves systemic chemotherapy and radiation therapy before surgery for patients with locally advanced rectal cancer, Christopher G. Willett, MD, explained, in an interview. However, recent clinical trials support several strategies for “deintensification” of TNT for patients with locally advanced rectal cancer, he said.

Some patients may not require surgery or radiation therapy, or they may not require any treatment modalities including radiation therapy, chemotherapy, and surgery, Dr. Willett continued.

However, “these patients require close surveillance post treatment to identify any recurrence that may require salvage treatment,” he added.

During a presentation at the 2024 National Comprehensive Cancer Network Annual Conference, Dr. Willett primarily discussed the following three strategies for deintensifying overall therapy for locally advanced rectal cancer:

• Selective surgical omission for patients with rectal cancer having a complete clinical response after TNT with close surveillance following treatment.
• Selective omission of radiation therapy for patients with surgery such as sphincter-sparing surgery.
• Selective omission of all treatment modalities (radiation therapy, chemotherapy and surgery). 

Does Watch and Wait Work?

Selective surgical omission, also known as a “watch and wait” or nonoperative management (NOM), involves treating patients with chemotherapy or a combination of chemo and radiation therapy but without surgery, Dr. Willett said during his presentation at the meeting.

Data from the OPRA trial published in the Journal of Clinical Oncology showed that 36% of patients who started on NOM developed tumor regrowth, most of which occurred in the first 2-3 years. Five-year disease-free survival rates were similar in patients who had total mesorectal excision (TME) upfront and those who had salvage TME procedures after tumor regrowth (61% and 62%, respectively). An update to the OPRA trial showed that the clinical outcomes persisted, and the results suggest no significant differences in disease-free survival between upfront surgery vs. watch and wait, Dr. Willett said.
 

Does Selective Omission of Radiotherapy Work?

Selective omission of radiotherapy is another option for reducing the overall treatment burden in patients with locally advanced rectal cancer, Dr. Willett. For these patients, who are at relatively low risk for recurrence, radiation along with surgery may not be needed.

Data from the FOWARC trial, published in the Journal of Clinical Oncology in 2016 and 2019, included 495 patients from 15 centers in China. In the randomized trial, the researchers found no significant difference in the primary outcome of disease-free survival between patients assigned in a 1:1:1 ratio to three arms:

• FOLFOX chemotherapy alone (a combination of chemotherapy drugs including folinic acid, fluorouracil, and oxaliplatin).
• FOLFOX plus chemoradiation.
• FU (fluorouracil)/LV (leucovorin calcium) plus chemoradiation.

Although the data were ultimately inconclusive because of potential staging bias, the findings were “promising for recommending radiation omission in these patients,” Dr. Willett said.

The larger PROSPECT study published in The New England Journal of Medicine in 2023 was similarly encouraging, he said. In this trial, 1194 patients with locally advanced rectal cancer were randomized to FOLFOX or chemoradiation prior to sphincter-sparing surgery. The two groups showed similar 5-year estimated overall survival, complete resection (R0), and pathological complete response.

“These further data support the idea that we don’t need radiotherapy anymore,” Dr. Willett said.

PROSPECT was “a very well-done trial” that also showed important patient reported outcomes, he said. At 12 months after surgery, patients in the chemoradiation group had higher scores on fatigue and neuropathy measures, but less than 15% were severe. Sexual function scores for men and women were worse in the chemoradiation group, although overall health-related quality-of-life scores were not significantly different between the groups, he noted.
 

Does Dropping Everything But Immunotherapy Work?

Research is very preliminary, but a small study of 12 patients with mismatch repair-deficit (MMRd) locally advanced rectal cancer published in The New England Journal of Medicine “lends optimism” to a personalized treatment approach via a programmed death 1 (PD-1) blockade, Dr. Willett said. The “small, but impressive numbers” showed that all 12 patients treated with dostarlimab only (an anti-PD-1 monoclonal antibody) had durable disease control at a follow-up of 6-24 months.

This option is feasible for patients with MMRd locally advanced rectal cancer, Dr. Willett said in an interview. “Patients treated with only dostarlimab (a PD-1 inhibitor) had excellent outcomes and did not require radiation therapy, chemotherapy, and surgery. This is potentially a new paradigm of treatment for MMRd rectal cancer.”

What are the Clinical Implications and Next Steps?

Patients should be carefully evaluated and selected for treatment approaches by experienced multidisciplinary teams with vigilant posttreatment surveillance, including history and physical exam, endoscopy, computed tomography (CT) of the chest, and abdomen and pelvic magnetic resonance imaging (MRI), Dr. Willett said in the interview.

Data on the treatment of patients with MMRd rectal cancer using dostarlimab and other immune checkpoint inhibitors are preliminary; more patients and further follow-up are required, he said. This treatment is applicable to only 5%-10% of patients with rectal cancer, he continued.

“There is a need for biomarkers such as circulating tumor DNA to further aid in selection and monitoring of patients with rectal cancer,” Dr. Willett said.

Other preliminary research is examining circulating tumor DNA analysis to guide adjuvant treatment for patients with resected stage II colon cancer, he noted in his presentation. Currently, ctDNA-driven therapy is not recommended by the NCCN, but more research is needed to determine whether this strategy might be applied to decision-making in rectal cancer patients, especially with watch and wait/nonoperative strategies, he said.
 

What Are the Takeaways for Deintensifying Treatment of Rectal Cancer?

The global continuum of rectal cancer clinical trials has provided significant evidence that, for select patients, the deintensification of treatment strategies may result in the avoidance of radiation and even avoidance of surgery, which can profoundly improve long-term quality of life, Al B. Benson III, MD, said in an interview.

“A critical takeaway message for clinicians who are determining which individual patient might benefit from a less intensive regimen to treat locally advanced rectal cancer is to first have a multidisciplinary consensus which should encompass review of a rectal MRI, pathology, chest and abdominal imaging, colonoscopy, as well as the patient’s clinical status including comorbidities,” said Dr. Benson, who served as chair of the NCCN Guidelines Panel for Colon/Rectal/Anal Cancers and Small Intestine Adenocarcinoma.

“The location of the rectal tumor (distal versus proximal) and clinical TNM stage also will inform the discussion as to which of the potential total neoadjuvant therapy regimens would be most optimal to reduce the risk of local recurrence and maintain long-term quality of life for the individual patient,” explained Dr. Benson, professor of medicine at Robert H. Lurie Comprehensive Cancer Center of Northwestern University in Chicago.

The effectiveness of less intense treatment for rectal cancer remains a work in progress, Dr. Benson said in an interview. “There is much we still do not know, such as the optimal selection of patients and the durability of this approach over time.”

Patients who undergo watch and wait require intensive follow-up, including sigmoidoscopy, digital rectal exam, and rectal MRI, to detect any evidence of local recurrence that would warrant further intervention, including possible radiation and surgery, he said. A highly skilled multidisciplinary team is a must for individuals who are potential candidates for a less intense treatment regimen, he emphasized.  

The treatment of locally advanced rectal cancer continues to evolve, but there is no question that TNT has transformed patient outcomes, including the ability to deintensify treatment for select patients, Dr. Benson said. 

However, many research gaps remain, Dr. Benson said in an interview. “For the MSI/dMMR patient who has achieved a complete response from immunotherapy we will need more long-term data to determine the durability of a complete clinical response and long-term avoidance of other interventions including radiation, chemotherapy and surgery.

“The wait and watch strategy for the much more common MSS patient also will require much longer follow-up to determine which patients are destined to recur and which are not,” he added.

“The introduction of monitoring with ctDNA determination over time offers an opportunity to streamline surveillance of patients who have completed combination therapy and for those undergoing watch and wait; however, much more information is required to determine which of the various ctDNA assays are most optimal, and the frequency and duration of ctDNA determination that will lend this approach as a standard of care,” Dr. Benson said.

Dr. Willett and Dr. Benson had no financial conflicts to disclose.

New and evolving research in locally advanced rectal cancer suggests that selective use of treatments in some patients can achieve outcomes similar to those of standard regimens, according to the chair of the Department of Radiation Oncology at Duke University School of Medicine, Durham, North Carolina.

Total neoadjuvant therapy (TNT) is the standard treatment that involves systemic chemotherapy and radiation therapy before surgery for patients with locally advanced rectal cancer, Christopher G. Willett, MD, explained, in an interview. However, recent clinical trials support several strategies for “deintensification” of TNT for patients with locally advanced rectal cancer, he said.

Some patients may not require surgery or radiation therapy, or they may not require any treatment modalities including radiation therapy, chemotherapy, and surgery, Dr. Willett continued.

However, “these patients require close surveillance post treatment to identify any recurrence that may require salvage treatment,” he added.

During a presentation at the 2024 National Comprehensive Cancer Network Annual Conference, Dr. Willett primarily discussed the following three strategies for deintensifying overall therapy for locally advanced rectal cancer:

• Selective surgical omission for patients with rectal cancer having a complete clinical response after TNT with close surveillance following treatment.
• Selective omission of radiation therapy for patients with surgery such as sphincter-sparing surgery.
• Selective omission of all treatment modalities (radiation therapy, chemotherapy and surgery). 

Does Watch and Wait Work?

Selective surgical omission, also known as a “watch and wait” or nonoperative management (NOM), involves treating patients with chemotherapy or a combination of chemo and radiation therapy but without surgery, Dr. Willett said during his presentation at the meeting.

Data from the OPRA trial published in the Journal of Clinical Oncology showed that 36% of patients who started on NOM developed tumor regrowth, most of which occurred in the first 2-3 years. Five-year disease-free survival rates were similar in patients who had total mesorectal excision (TME) upfront and those who had salvage TME procedures after tumor regrowth (61% and 62%, respectively). An update to the OPRA trial showed that the clinical outcomes persisted, and the results suggest no significant differences in disease-free survival between upfront surgery vs. watch and wait, Dr. Willett said.
 

Does Selective Omission of Radiotherapy Work?

Selective omission of radiotherapy is another option for reducing the overall treatment burden in patients with locally advanced rectal cancer, Dr. Willett. For these patients, who are at relatively low risk for recurrence, radiation along with surgery may not be needed.

Data from the FOWARC trial, published in the Journal of Clinical Oncology in 2016 and 2019, included 495 patients from 15 centers in China. In the randomized trial, the researchers found no significant difference in the primary outcome of disease-free survival between patients assigned in a 1:1:1 ratio to three arms:

• FOLFOX chemotherapy alone (a combination of chemotherapy drugs including folinic acid, fluorouracil, and oxaliplatin).
• FOLFOX plus chemoradiation.
• FU (fluorouracil)/LV (leucovorin calcium) plus chemoradiation.

Although the data were ultimately inconclusive because of potential staging bias, the findings were “promising for recommending radiation omission in these patients,” Dr. Willett said.

The larger PROSPECT study published in The New England Journal of Medicine in 2023 was similarly encouraging, he said. In this trial, 1194 patients with locally advanced rectal cancer were randomized to FOLFOX or chemoradiation prior to sphincter-sparing surgery. The two groups showed similar 5-year estimated overall survival, complete resection (R0), and pathological complete response.

“These further data support the idea that we don’t need radiotherapy anymore,” Dr. Willett said.

PROSPECT was “a very well-done trial” that also showed important patient reported outcomes, he said. At 12 months after surgery, patients in the chemoradiation group had higher scores on fatigue and neuropathy measures, but less than 15% were severe. Sexual function scores for men and women were worse in the chemoradiation group, although overall health-related quality-of-life scores were not significantly different between the groups, he noted.
 

Does Dropping Everything But Immunotherapy Work?

Research is very preliminary, but a small study of 12 patients with mismatch repair-deficit (MMRd) locally advanced rectal cancer published in The New England Journal of Medicine “lends optimism” to a personalized treatment approach via a programmed death 1 (PD-1) blockade, Dr. Willett said. The “small, but impressive numbers” showed that all 12 patients treated with dostarlimab only (an anti-PD-1 monoclonal antibody) had durable disease control at a follow-up of 6-24 months.

This option is feasible for patients with MMRd locally advanced rectal cancer, Dr. Willett said in an interview. “Patients treated with only dostarlimab (a PD-1 inhibitor) had excellent outcomes and did not require radiation therapy, chemotherapy, and surgery. This is potentially a new paradigm of treatment for MMRd rectal cancer.”

What are the Clinical Implications and Next Steps?

Patients should be carefully evaluated and selected for treatment approaches by experienced multidisciplinary teams with vigilant posttreatment surveillance, including history and physical exam, endoscopy, computed tomography (CT) of the chest, and abdomen and pelvic magnetic resonance imaging (MRI), Dr. Willett said in the interview.

Data on the treatment of patients with MMRd rectal cancer using dostarlimab and other immune checkpoint inhibitors are preliminary; more patients and further follow-up are required, he said. This treatment is applicable to only 5%-10% of patients with rectal cancer, he continued.

“There is a need for biomarkers such as circulating tumor DNA to further aid in selection and monitoring of patients with rectal cancer,” Dr. Willett said.

Other preliminary research is examining circulating tumor DNA analysis to guide adjuvant treatment for patients with resected stage II colon cancer, he noted in his presentation. Currently, ctDNA-driven therapy is not recommended by the NCCN, but more research is needed to determine whether this strategy might be applied to decision-making in rectal cancer patients, especially with watch and wait/nonoperative strategies, he said.
 

What Are the Takeaways for Deintensifying Treatment of Rectal Cancer?

The global continuum of rectal cancer clinical trials has provided significant evidence that, for select patients, the deintensification of treatment strategies may result in the avoidance of radiation and even avoidance of surgery, which can profoundly improve long-term quality of life, Al B. Benson III, MD, said in an interview.

“A critical takeaway message for clinicians who are determining which individual patient might benefit from a less intensive regimen to treat locally advanced rectal cancer is to first have a multidisciplinary consensus which should encompass review of a rectal MRI, pathology, chest and abdominal imaging, colonoscopy, as well as the patient’s clinical status including comorbidities,” said Dr. Benson, who served as chair of the NCCN Guidelines Panel for Colon/Rectal/Anal Cancers and Small Intestine Adenocarcinoma.

“The location of the rectal tumor (distal versus proximal) and clinical TNM stage also will inform the discussion as to which of the potential total neoadjuvant therapy regimens would be most optimal to reduce the risk of local recurrence and maintain long-term quality of life for the individual patient,” explained Dr. Benson, professor of medicine at Robert H. Lurie Comprehensive Cancer Center of Northwestern University in Chicago.

The effectiveness of less intense treatment for rectal cancer remains a work in progress, Dr. Benson said in an interview. “There is much we still do not know, such as the optimal selection of patients and the durability of this approach over time.”

Patients who undergo watch and wait require intensive follow-up, including sigmoidoscopy, digital rectal exam, and rectal MRI, to detect any evidence of local recurrence that would warrant further intervention, including possible radiation and surgery, he said. A highly skilled multidisciplinary team is a must for individuals who are potential candidates for a less intense treatment regimen, he emphasized.  

The treatment of locally advanced rectal cancer continues to evolve, but there is no question that TNT has transformed patient outcomes, including the ability to deintensify treatment for select patients, Dr. Benson said. 

However, many research gaps remain, Dr. Benson said in an interview. “For the MSI/dMMR patient who has achieved a complete response from immunotherapy we will need more long-term data to determine the durability of a complete clinical response and long-term avoidance of other interventions including radiation, chemotherapy and surgery.

“The wait and watch strategy for the much more common MSS patient also will require much longer follow-up to determine which patients are destined to recur and which are not,” he added.

“The introduction of monitoring with ctDNA determination over time offers an opportunity to streamline surveillance of patients who have completed combination therapy and for those undergoing watch and wait; however, much more information is required to determine which of the various ctDNA assays are most optimal, and the frequency and duration of ctDNA determination that will lend this approach as a standard of care,” Dr. Benson said.

Dr. Willett and Dr. Benson had no financial conflicts to disclose.

New and evolving research in locally advanced rectal cancer suggests that selective use of treatments in some patients can achieve outcomes similar to those of standard regimens, according to the chair of the Department of Radiation Oncology at Duke University School of Medicine, Durham, North Carolina.

Total neoadjuvant therapy (TNT) is the standard treatment that involves systemic chemotherapy and radiation therapy before surgery for patients with locally advanced rectal cancer, Christopher G. Willett, MD, explained, in an interview. However, recent clinical trials support several strategies for “deintensification” of TNT for patients with locally advanced rectal cancer, he said.

Some patients may not require surgery or radiation therapy, or they may not require any treatment modalities including radiation therapy, chemotherapy, and surgery, Dr. Willett continued.

However, “these patients require close surveillance post treatment to identify any recurrence that may require salvage treatment,” he added.

During a presentation at the 2024 National Comprehensive Cancer Network Annual Conference, Dr. Willett primarily discussed the following three strategies for deintensifying overall therapy for locally advanced rectal cancer:

• Selective surgical omission for patients with rectal cancer having a complete clinical response after TNT with close surveillance following treatment.
• Selective omission of radiation therapy for patients with surgery such as sphincter-sparing surgery.
• Selective omission of all treatment modalities (radiation therapy, chemotherapy and surgery). 

Does Watch and Wait Work?

Selective surgical omission, also known as a “watch and wait” or nonoperative management (NOM), involves treating patients with chemotherapy or a combination of chemo and radiation therapy but without surgery, Dr. Willett said during his presentation at the meeting.

Data from the OPRA trial published in the Journal of Clinical Oncology showed that 36% of patients who started on NOM developed tumor regrowth, most of which occurred in the first 2-3 years. Five-year disease-free survival rates were similar in patients who had total mesorectal excision (TME) upfront and those who had salvage TME procedures after tumor regrowth (61% and 62%, respectively). An update to the OPRA trial showed that the clinical outcomes persisted, and the results suggest no significant differences in disease-free survival between upfront surgery vs. watch and wait, Dr. Willett said.
 

Does Selective Omission of Radiotherapy Work?

Selective omission of radiotherapy is another option for reducing the overall treatment burden in patients with locally advanced rectal cancer, Dr. Willett. For these patients, who are at relatively low risk for recurrence, radiation along with surgery may not be needed.

Data from the FOWARC trial, published in the Journal of Clinical Oncology in 2016 and 2019, included 495 patients from 15 centers in China. In the randomized trial, the researchers found no significant difference in the primary outcome of disease-free survival between patients assigned in a 1:1:1 ratio to three arms:

• FOLFOX chemotherapy alone (a combination of chemotherapy drugs including folinic acid, fluorouracil, and oxaliplatin).
• FOLFOX plus chemoradiation.
• FU (fluorouracil)/LV (leucovorin calcium) plus chemoradiation.

Although the data were ultimately inconclusive because of potential staging bias, the findings were “promising for recommending radiation omission in these patients,” Dr. Willett said.

The larger PROSPECT study published in The New England Journal of Medicine in 2023 was similarly encouraging, he said. In this trial, 1194 patients with locally advanced rectal cancer were randomized to FOLFOX or chemoradiation prior to sphincter-sparing surgery. The two groups showed similar 5-year estimated overall survival, complete resection (R0), and pathological complete response.

“These further data support the idea that we don’t need radiotherapy anymore,” Dr. Willett said.

PROSPECT was “a very well-done trial” that also showed important patient reported outcomes, he said. At 12 months after surgery, patients in the chemoradiation group had higher scores on fatigue and neuropathy measures, but less than 15% were severe. Sexual function scores for men and women were worse in the chemoradiation group, although overall health-related quality-of-life scores were not significantly different between the groups, he noted.
 

Does Dropping Everything But Immunotherapy Work?

Research is very preliminary, but a small study of 12 patients with mismatch repair-deficit (MMRd) locally advanced rectal cancer published in The New England Journal of Medicine “lends optimism” to a personalized treatment approach via a programmed death 1 (PD-1) blockade, Dr. Willett said. The “small, but impressive numbers” showed that all 12 patients treated with dostarlimab only (an anti-PD-1 monoclonal antibody) had durable disease control at a follow-up of 6-24 months.

This option is feasible for patients with MMRd locally advanced rectal cancer, Dr. Willett said in an interview. “Patients treated with only dostarlimab (a PD-1 inhibitor) had excellent outcomes and did not require radiation therapy, chemotherapy, and surgery. This is potentially a new paradigm of treatment for MMRd rectal cancer.”

What are the Clinical Implications and Next Steps?

Patients should be carefully evaluated and selected for treatment approaches by experienced multidisciplinary teams with vigilant posttreatment surveillance, including history and physical exam, endoscopy, computed tomography (CT) of the chest, and abdomen and pelvic magnetic resonance imaging (MRI), Dr. Willett said in the interview.

Data on the treatment of patients with MMRd rectal cancer using dostarlimab and other immune checkpoint inhibitors are preliminary; more patients and further follow-up are required, he said. This treatment is applicable to only 5%-10% of patients with rectal cancer, he continued.

“There is a need for biomarkers such as circulating tumor DNA to further aid in selection and monitoring of patients with rectal cancer,” Dr. Willett said.

Other preliminary research is examining circulating tumor DNA analysis to guide adjuvant treatment for patients with resected stage II colon cancer, he noted in his presentation. Currently, ctDNA-driven therapy is not recommended by the NCCN, but more research is needed to determine whether this strategy might be applied to decision-making in rectal cancer patients, especially with watch and wait/nonoperative strategies, he said.
 

What Are the Takeaways for Deintensifying Treatment of Rectal Cancer?

The global continuum of rectal cancer clinical trials has provided significant evidence that, for select patients, the deintensification of treatment strategies may result in the avoidance of radiation and even avoidance of surgery, which can profoundly improve long-term quality of life, Al B. Benson III, MD, said in an interview.

“A critical takeaway message for clinicians who are determining which individual patient might benefit from a less intensive regimen to treat locally advanced rectal cancer is to first have a multidisciplinary consensus which should encompass review of a rectal MRI, pathology, chest and abdominal imaging, colonoscopy, as well as the patient’s clinical status including comorbidities,” said Dr. Benson, who served as chair of the NCCN Guidelines Panel for Colon/Rectal/Anal Cancers and Small Intestine Adenocarcinoma.

“The location of the rectal tumor (distal versus proximal) and clinical TNM stage also will inform the discussion as to which of the potential total neoadjuvant therapy regimens would be most optimal to reduce the risk of local recurrence and maintain long-term quality of life for the individual patient,” explained Dr. Benson, professor of medicine at Robert H. Lurie Comprehensive Cancer Center of Northwestern University in Chicago.

The effectiveness of less intense treatment for rectal cancer remains a work in progress, Dr. Benson said in an interview. “There is much we still do not know, such as the optimal selection of patients and the durability of this approach over time.”

Patients who undergo watch and wait require intensive follow-up, including sigmoidoscopy, digital rectal exam, and rectal MRI, to detect any evidence of local recurrence that would warrant further intervention, including possible radiation and surgery, he said. A highly skilled multidisciplinary team is a must for individuals who are potential candidates for a less intense treatment regimen, he emphasized.  

The treatment of locally advanced rectal cancer continues to evolve, but there is no question that TNT has transformed patient outcomes, including the ability to deintensify treatment for select patients, Dr. Benson said. 

However, many research gaps remain, Dr. Benson said in an interview. “For the MSI/dMMR patient who has achieved a complete response from immunotherapy we will need more long-term data to determine the durability of a complete clinical response and long-term avoidance of other interventions including radiation, chemotherapy and surgery.

“The wait and watch strategy for the much more common MSS patient also will require much longer follow-up to determine which patients are destined to recur and which are not,” he added.

“The introduction of monitoring with ctDNA determination over time offers an opportunity to streamline surveillance of patients who have completed combination therapy and for those undergoing watch and wait; however, much more information is required to determine which of the various ctDNA assays are most optimal, and the frequency and duration of ctDNA determination that will lend this approach as a standard of care,” Dr. Benson said.

Dr. Willett and Dr. Benson had no financial conflicts to disclose.

Companies selling gut microbiome tests directly to consumers offer up a variety of claims to promote their products.

“We analyze the trillions of microbes in your gut microflora and craft a unique formula for your unique gut needs,” one says. “Get actionable dietary, supplement, and lifestyle recommendations from our microbiome experts based on your results, tailored to mom and baby’s biomarkers. ... Any family member like dads or siblings are welcome too,” says another.

The companies assert that they can improve gut health by offering individuals personalized treatments based on their gut microbiome test results. The trouble is, no provider, company, or technology can reliably do that yet.
 

Clinical Implications, Not Applications

The microbiome is the “constellation of microorganisms that call the human body home,” including many strains of bacteria, fungi, and viruses. That constellation comprises some 39 trillion cells.

Although knowledge is increasing on the oral, cutaneous, and vaginal microbiomes, the gut microbiome is arguably the most studied. However, while research is increasingly demonstrating that the gut microbiome has clinical implications, much work needs to be done before reliable applications based on that research are available.

But lack of scientific evidence and validity hasn’t stopped a growing number of companies across the globe from offering direct-to-consumer (DTC) microbiome tests, Erik C. von Rosenvinge, MD, AGAF, a professor at the University of Maryland School of Medicine and chief of gastroenterology at the VA Maryland Health Care System, Baltimore, said in an interview.

“If you go to their websites, even if it’s not stated overtly, these companies at least give the impression that they’re providing actionable, useful information,” he said. “The sites recommend microbiome testing, and often supplements, probiotics, or other products that they sell. And consumers are told they need to be tested again once they start taking any of these products to see if they’re receiving any benefit.”

Dr. von Rosenvinge and colleagues authored a recent article in Science  arguing that DTC microbiome tests “lack analytical and clinical validity” — and yet regulation of the industry has been “generally ignored.” They identified 31 companies globally, 17 of which are based in the United States, claiming to have products and/or services aimed at changing the intestinal microbiome.
 

Unreliable, Unregulated

The lack of reliability has been shown by experts who have tested the tests.

“People have taken the same stool sample, sent it to multiple companies, and gotten different results back,” Dr. von Rosenvinge said. “People also have taken a stool sample and sent it to the same company under two different names and received two different results. If the test is unreliable at its foundational level, it’s hard to use it in any clinical way.”

Test users’ methods and the companies’ procedures can affect the results, Dina Kao, MD, a professor at the University of Alberta, Edmonton, Alberta, Canada, said in an interview.

“So many biases can be introduced at every single step of the way, starting from how the stool sample was collected and how it’s preserved or not being preserved, because that can introduce a lot of noise that would change the analyses. Which primer they’re using to amplify the signals and which bioinformatic pipeline they use are also important,” said Dr. Kao, who presented at the recent Gut Microbiota for Health World Summit, organized by the American Gastroenterological Association (AGA) and the European Society of Neurogastroenterology and Motility (ESNM).

Different investigators and companies use different technologies, so it’s very difficult to compare them and to create a standard, said Mahmoud Ghannoum, PhD, a professor in the dermatology and pathology departments at Case Western Reserve University School of Medicine and director of the Center for Medical Mycology at University Hospitals in Cleveland.

The complexity of the gut microbiome makes test standardization more difficult than it is when just one organism is involved, Dr. Ghannoum, who chaired the antifungal subcommittee at the Clinical and Laboratory Standards Institute, said in an interview.

“Even though many researchers are focusing on bacteria, we also have fungi and viruses. We need standardization of methods for testing these organisms if we want to have regulations,” said Dr. Ghannoum, a cofounder of BIOHM, a microbiome company that offers nondiagnostic tests and markets a variety of probiotics, prebiotics, and immunity supplements. BIOHM is one of the 31 companies identified by Dr. von Rosenvinge and colleagues, as noted above.

Dr. Ghannoum believes that taking a systematic approach could facilitate standardization and, ultimately, regulation of the DTC microbiome testing products. He and his colleagues described such an approach by outlining the stages for designing probiotics capable of modulating the microbiome in chronic diseases, using Crohn’s disease as a model. Their strategy involved the following steps:

• Using primary microbiome data to identify, by abundance, the microorganisms underlying dysbiosis.
• Gaining insight into the interactions among the identified pathogens.
• Conducting a correlation analysis to identify potential lead probiotic strains that antagonize these pathogens and discovering metabolites that can interrupt their interactions.
• Creating a prototype formulation for testing.
• Validating the efficacy of the candidate formulation via preclinical in vitro and in vivo testing.
• Conducting clinical testing.

Dr. Ghannoum recommends that companies use a similar process “to provide evidence that what they are doing will be helpful, not only for them but also for the reputation of the whole industry.”
 

Potential Pitfalls

Whether test results from commercial companies are positioned as wellness aids or diagnostic tools, providing advice based on the results “is where the danger can really come in,” Dr. Kao said. “There is still so much we don’t know about which microbial signatures are associated with each condition.”

“Even when we have a solution, like the Crohn’s exclusion diet, a physician doesn’t know enough of the nuances to give advice to a patient,” she said. “That really should be done under the guidance of an expert dietitian. And if a company is selling probiotics, I personally feel that’s not ethical. I’m pretty sure there’s always going to be some kind of conflict of interest.”

Supplements and probiotics are generally safe, but negative consequences can occur, Dr. von Rosenvinge noted.

“We occasionally see people who end up with liver problems as a result of certain supplements, and rarely, probiotics have been associated with infections from those organisms, usually in those with a compromised immune system,” he said.

Other risks include people taking supplements or probiotics when they actually have a medically treatable condition or delays in diagnosis of a potentially serious underlying condition, such as colon cancer, he said. Some patients may stop taking their traditional medication in favor of taking supplements or may experience a drug-supplement interaction if they take both.
 

What to Tell Patients

“Doctors should be advising against this testing for their patients,” gastroenterologist Colleen R. Kelly, MD, AGAF, Brigham and Women’s Hospital, Boston, said in an interview. “I explain to patients that these tests are not validated and are clinically meaningless data and not worth the money. There is a reason they are not covered by insurance.

Kelly_Colleen_WEB.jpg

“Recommendations to purchase probiotics or supplements manufactured by the testing company to ‘restore a balanced or healthy microbiome’ clearly seem like a scam,” she added. “I believe some of these companies are capitalizing on patients who are desperate for answers to explain chronic symptoms, such as bloating in irritable bowel syndrome.”

Dr. von Rosenvinge said that the message to patients “is that the science isn’t there yet to support using the results of these tests in a meaningful way. We believe the microbiome is very important in health and disease, but the tests themselves in their current state are not as reliable and reproducible as we would like.”

When patients come in with test results, the first question a clinician should ask is what led them to seek out this type of information in the first place, Dr. von Rosenvinge said.

“Our patient focus groups suggested that many have not gotten clear, satisfactory answers from traditional medicine,” he said. “We don’t have a single test that says, yes, you have irritable bowel syndrome, or no, you don’t. We might suggest things that are helpful for some people and are less helpful for others.”

Dr. Kelly said she worries that “there are snake oil salesmen and cons out there who will gladly take your money. These may be smart people, capable of doing very high-level testing, and even producing very detailed and accurate results, but that doesn’t mean we know what to do with them.”

She hopes to see a microbiome-based diagnostic test in the future, particularly if the ability to therapeutically manipulate the gut microbiome in various diseases becomes a reality.
 

Educate Clinicians, Companies

More education is needed on the subject, so we can become “microbial clinicians,” Dr. Kao said.

“The microbiome never came up when I was going through my medical education,” she said. But we, and the next generation of physicians, “need to at least be able to understand the basics.

“Hopefully, one day, we will be in a position where we can have meaningful interpretations of the test results and make some kind of meaningful dietary interventions,” Dr. Kao added.

As for clinicians who are currently ordering these tests and products directly from the DTC companies, Dr. Kao said, “I roll my eyes.”

Dr. Ghannoum reiterated that companies offering microbiome tests and products also need to be educated and encouraged to use systematic approaches to product development and interpretation.

“Companies should be open to calls from clinicians and be ready to explain findings on a report, as well as the basis for any recommendations,” he said.

Dr. von Rosenvinge, Dr. Kao, and Dr. Kelly had no relevant conflicts of interest. Dr. Ghannoum is a cofounder of BIOHM.

A version of this article appeared on Medscape.com.

Companies selling gut microbiome tests directly to consumers offer up a variety of claims to promote their products.

“We analyze the trillions of microbes in your gut microflora and craft a unique formula for your unique gut needs,” one says. “Get actionable dietary, supplement, and lifestyle recommendations from our microbiome experts based on your results, tailored to mom and baby’s biomarkers. ... Any family member like dads or siblings are welcome too,” says another.

The companies assert that they can improve gut health by offering individuals personalized treatments based on their gut microbiome test results. The trouble is, no provider, company, or technology can reliably do that yet.
 

Clinical Implications, Not Applications

The microbiome is the “constellation of microorganisms that call the human body home,” including many strains of bacteria, fungi, and viruses. That constellation comprises some 39 trillion cells.

Although knowledge is increasing on the oral, cutaneous, and vaginal microbiomes, the gut microbiome is arguably the most studied. However, while research is increasingly demonstrating that the gut microbiome has clinical implications, much work needs to be done before reliable applications based on that research are available.

But lack of scientific evidence and validity hasn’t stopped a growing number of companies across the globe from offering direct-to-consumer (DTC) microbiome tests, Erik C. von Rosenvinge, MD, AGAF, a professor at the University of Maryland School of Medicine and chief of gastroenterology at the VA Maryland Health Care System, Baltimore, said in an interview.

“If you go to their websites, even if it’s not stated overtly, these companies at least give the impression that they’re providing actionable, useful information,” he said. “The sites recommend microbiome testing, and often supplements, probiotics, or other products that they sell. And consumers are told they need to be tested again once they start taking any of these products to see if they’re receiving any benefit.”

Dr. von Rosenvinge and colleagues authored a recent article in Science  arguing that DTC microbiome tests “lack analytical and clinical validity” — and yet regulation of the industry has been “generally ignored.” They identified 31 companies globally, 17 of which are based in the United States, claiming to have products and/or services aimed at changing the intestinal microbiome.
 

Unreliable, Unregulated

The lack of reliability has been shown by experts who have tested the tests.

“People have taken the same stool sample, sent it to multiple companies, and gotten different results back,” Dr. von Rosenvinge said. “People also have taken a stool sample and sent it to the same company under two different names and received two different results. If the test is unreliable at its foundational level, it’s hard to use it in any clinical way.”

Test users’ methods and the companies’ procedures can affect the results, Dina Kao, MD, a professor at the University of Alberta, Edmonton, Alberta, Canada, said in an interview.

“So many biases can be introduced at every single step of the way, starting from how the stool sample was collected and how it’s preserved or not being preserved, because that can introduce a lot of noise that would change the analyses. Which primer they’re using to amplify the signals and which bioinformatic pipeline they use are also important,” said Dr. Kao, who presented at the recent Gut Microbiota for Health World Summit, organized by the American Gastroenterological Association (AGA) and the European Society of Neurogastroenterology and Motility (ESNM).

Different investigators and companies use different technologies, so it’s very difficult to compare them and to create a standard, said Mahmoud Ghannoum, PhD, a professor in the dermatology and pathology departments at Case Western Reserve University School of Medicine and director of the Center for Medical Mycology at University Hospitals in Cleveland.

The complexity of the gut microbiome makes test standardization more difficult than it is when just one organism is involved, Dr. Ghannoum, who chaired the antifungal subcommittee at the Clinical and Laboratory Standards Institute, said in an interview.

“Even though many researchers are focusing on bacteria, we also have fungi and viruses. We need standardization of methods for testing these organisms if we want to have regulations,” said Dr. Ghannoum, a cofounder of BIOHM, a microbiome company that offers nondiagnostic tests and markets a variety of probiotics, prebiotics, and immunity supplements. BIOHM is one of the 31 companies identified by Dr. von Rosenvinge and colleagues, as noted above.

Dr. Ghannoum believes that taking a systematic approach could facilitate standardization and, ultimately, regulation of the DTC microbiome testing products. He and his colleagues described such an approach by outlining the stages for designing probiotics capable of modulating the microbiome in chronic diseases, using Crohn’s disease as a model. Their strategy involved the following steps:

• Using primary microbiome data to identify, by abundance, the microorganisms underlying dysbiosis.
• Gaining insight into the interactions among the identified pathogens.
• Conducting a correlation analysis to identify potential lead probiotic strains that antagonize these pathogens and discovering metabolites that can interrupt their interactions.
• Creating a prototype formulation for testing.
• Validating the efficacy of the candidate formulation via preclinical in vitro and in vivo testing.
• Conducting clinical testing.

Dr. Ghannoum recommends that companies use a similar process “to provide evidence that what they are doing will be helpful, not only for them but also for the reputation of the whole industry.”
 

Potential Pitfalls

Whether test results from commercial companies are positioned as wellness aids or diagnostic tools, providing advice based on the results “is where the danger can really come in,” Dr. Kao said. “There is still so much we don’t know about which microbial signatures are associated with each condition.”

“Even when we have a solution, like the Crohn’s exclusion diet, a physician doesn’t know enough of the nuances to give advice to a patient,” she said. “That really should be done under the guidance of an expert dietitian. And if a company is selling probiotics, I personally feel that’s not ethical. I’m pretty sure there’s always going to be some kind of conflict of interest.”

Supplements and probiotics are generally safe, but negative consequences can occur, Dr. von Rosenvinge noted.

“We occasionally see people who end up with liver problems as a result of certain supplements, and rarely, probiotics have been associated with infections from those organisms, usually in those with a compromised immune system,” he said.

Other risks include people taking supplements or probiotics when they actually have a medically treatable condition or delays in diagnosis of a potentially serious underlying condition, such as colon cancer, he said. Some patients may stop taking their traditional medication in favor of taking supplements or may experience a drug-supplement interaction if they take both.
 

What to Tell Patients

“Doctors should be advising against this testing for their patients,” gastroenterologist Colleen R. Kelly, MD, AGAF, Brigham and Women’s Hospital, Boston, said in an interview. “I explain to patients that these tests are not validated and are clinically meaningless data and not worth the money. There is a reason they are not covered by insurance.

Kelly_Colleen_WEB.jpg

“Recommendations to purchase probiotics or supplements manufactured by the testing company to ‘restore a balanced or healthy microbiome’ clearly seem like a scam,” she added. “I believe some of these companies are capitalizing on patients who are desperate for answers to explain chronic symptoms, such as bloating in irritable bowel syndrome.”

Dr. von Rosenvinge said that the message to patients “is that the science isn’t there yet to support using the results of these tests in a meaningful way. We believe the microbiome is very important in health and disease, but the tests themselves in their current state are not as reliable and reproducible as we would like.”

When patients come in with test results, the first question a clinician should ask is what led them to seek out this type of information in the first place, Dr. von Rosenvinge said.

“Our patient focus groups suggested that many have not gotten clear, satisfactory answers from traditional medicine,” he said. “We don’t have a single test that says, yes, you have irritable bowel syndrome, or no, you don’t. We might suggest things that are helpful for some people and are less helpful for others.”

Dr. Kelly said she worries that “there are snake oil salesmen and cons out there who will gladly take your money. These may be smart people, capable of doing very high-level testing, and even producing very detailed and accurate results, but that doesn’t mean we know what to do with them.”

She hopes to see a microbiome-based diagnostic test in the future, particularly if the ability to therapeutically manipulate the gut microbiome in various diseases becomes a reality.
 

Educate Clinicians, Companies

More education is needed on the subject, so we can become “microbial clinicians,” Dr. Kao said.

“The microbiome never came up when I was going through my medical education,” she said. But we, and the next generation of physicians, “need to at least be able to understand the basics.

“Hopefully, one day, we will be in a position where we can have meaningful interpretations of the test results and make some kind of meaningful dietary interventions,” Dr. Kao added.

As for clinicians who are currently ordering these tests and products directly from the DTC companies, Dr. Kao said, “I roll my eyes.”

Dr. Ghannoum reiterated that companies offering microbiome tests and products also need to be educated and encouraged to use systematic approaches to product development and interpretation.

“Companies should be open to calls from clinicians and be ready to explain findings on a report, as well as the basis for any recommendations,” he said.

Dr. von Rosenvinge, Dr. Kao, and Dr. Kelly had no relevant conflicts of interest. Dr. Ghannoum is a cofounder of BIOHM.

A version of this article appeared on Medscape.com.

Companies selling gut microbiome tests directly to consumers offer up a variety of claims to promote their products.

“We analyze the trillions of microbes in your gut microflora and craft a unique formula for your unique gut needs,” one says. “Get actionable dietary, supplement, and lifestyle recommendations from our microbiome experts based on your results, tailored to mom and baby’s biomarkers. ... Any family member like dads or siblings are welcome too,” says another.

The companies assert that they can improve gut health by offering individuals personalized treatments based on their gut microbiome test results. The trouble is, no provider, company, or technology can reliably do that yet.
 

Clinical Implications, Not Applications

The microbiome is the “constellation of microorganisms that call the human body home,” including many strains of bacteria, fungi, and viruses. That constellation comprises some 39 trillion cells.

Although knowledge is increasing on the oral, cutaneous, and vaginal microbiomes, the gut microbiome is arguably the most studied. However, while research is increasingly demonstrating that the gut microbiome has clinical implications, much work needs to be done before reliable applications based on that research are available.

But lack of scientific evidence and validity hasn’t stopped a growing number of companies across the globe from offering direct-to-consumer (DTC) microbiome tests, Erik C. von Rosenvinge, MD, AGAF, a professor at the University of Maryland School of Medicine and chief of gastroenterology at the VA Maryland Health Care System, Baltimore, said in an interview.

“If you go to their websites, even if it’s not stated overtly, these companies at least give the impression that they’re providing actionable, useful information,” he said. “The sites recommend microbiome testing, and often supplements, probiotics, or other products that they sell. And consumers are told they need to be tested again once they start taking any of these products to see if they’re receiving any benefit.”

Dr. von Rosenvinge and colleagues authored a recent article in Science  arguing that DTC microbiome tests “lack analytical and clinical validity” — and yet regulation of the industry has been “generally ignored.” They identified 31 companies globally, 17 of which are based in the United States, claiming to have products and/or services aimed at changing the intestinal microbiome.
 

Unreliable, Unregulated

The lack of reliability has been shown by experts who have tested the tests.

“People have taken the same stool sample, sent it to multiple companies, and gotten different results back,” Dr. von Rosenvinge said. “People also have taken a stool sample and sent it to the same company under two different names and received two different results. If the test is unreliable at its foundational level, it’s hard to use it in any clinical way.”

Test users’ methods and the companies’ procedures can affect the results, Dina Kao, MD, a professor at the University of Alberta, Edmonton, Alberta, Canada, said in an interview.

“So many biases can be introduced at every single step of the way, starting from how the stool sample was collected and how it’s preserved or not being preserved, because that can introduce a lot of noise that would change the analyses. Which primer they’re using to amplify the signals and which bioinformatic pipeline they use are also important,” said Dr. Kao, who presented at the recent Gut Microbiota for Health World Summit, organized by the American Gastroenterological Association (AGA) and the European Society of Neurogastroenterology and Motility (ESNM).

Different investigators and companies use different technologies, so it’s very difficult to compare them and to create a standard, said Mahmoud Ghannoum, PhD, a professor in the dermatology and pathology departments at Case Western Reserve University School of Medicine and director of the Center for Medical Mycology at University Hospitals in Cleveland.

The complexity of the gut microbiome makes test standardization more difficult than it is when just one organism is involved, Dr. Ghannoum, who chaired the antifungal subcommittee at the Clinical and Laboratory Standards Institute, said in an interview.

“Even though many researchers are focusing on bacteria, we also have fungi and viruses. We need standardization of methods for testing these organisms if we want to have regulations,” said Dr. Ghannoum, a cofounder of BIOHM, a microbiome company that offers nondiagnostic tests and markets a variety of probiotics, prebiotics, and immunity supplements. BIOHM is one of the 31 companies identified by Dr. von Rosenvinge and colleagues, as noted above.

Dr. Ghannoum believes that taking a systematic approach could facilitate standardization and, ultimately, regulation of the DTC microbiome testing products. He and his colleagues described such an approach by outlining the stages for designing probiotics capable of modulating the microbiome in chronic diseases, using Crohn’s disease as a model. Their strategy involved the following steps:

• Using primary microbiome data to identify, by abundance, the microorganisms underlying dysbiosis.
• Gaining insight into the interactions among the identified pathogens.
• Conducting a correlation analysis to identify potential lead probiotic strains that antagonize these pathogens and discovering metabolites that can interrupt their interactions.
• Creating a prototype formulation for testing.
• Validating the efficacy of the candidate formulation via preclinical in vitro and in vivo testing.
• Conducting clinical testing.

Dr. Ghannoum recommends that companies use a similar process “to provide evidence that what they are doing will be helpful, not only for them but also for the reputation of the whole industry.”
 

Potential Pitfalls

Whether test results from commercial companies are positioned as wellness aids or diagnostic tools, providing advice based on the results “is where the danger can really come in,” Dr. Kao said. “There is still so much we don’t know about which microbial signatures are associated with each condition.”

“Even when we have a solution, like the Crohn’s exclusion diet, a physician doesn’t know enough of the nuances to give advice to a patient,” she said. “That really should be done under the guidance of an expert dietitian. And if a company is selling probiotics, I personally feel that’s not ethical. I’m pretty sure there’s always going to be some kind of conflict of interest.”

Supplements and probiotics are generally safe, but negative consequences can occur, Dr. von Rosenvinge noted.

“We occasionally see people who end up with liver problems as a result of certain supplements, and rarely, probiotics have been associated with infections from those organisms, usually in those with a compromised immune system,” he said.

Other risks include people taking supplements or probiotics when they actually have a medically treatable condition or delays in diagnosis of a potentially serious underlying condition, such as colon cancer, he said. Some patients may stop taking their traditional medication in favor of taking supplements or may experience a drug-supplement interaction if they take both.
 

What to Tell Patients

“Doctors should be advising against this testing for their patients,” gastroenterologist Colleen R. Kelly, MD, AGAF, Brigham and Women’s Hospital, Boston, said in an interview. “I explain to patients that these tests are not validated and are clinically meaningless data and not worth the money. There is a reason they are not covered by insurance.

Kelly_Colleen_WEB.jpg

“Recommendations to purchase probiotics or supplements manufactured by the testing company to ‘restore a balanced or healthy microbiome’ clearly seem like a scam,” she added. “I believe some of these companies are capitalizing on patients who are desperate for answers to explain chronic symptoms, such as bloating in irritable bowel syndrome.”

Dr. von Rosenvinge said that the message to patients “is that the science isn’t there yet to support using the results of these tests in a meaningful way. We believe the microbiome is very important in health and disease, but the tests themselves in their current state are not as reliable and reproducible as we would like.”

When patients come in with test results, the first question a clinician should ask is what led them to seek out this type of information in the first place, Dr. von Rosenvinge said.

“Our patient focus groups suggested that many have not gotten clear, satisfactory answers from traditional medicine,” he said. “We don’t have a single test that says, yes, you have irritable bowel syndrome, or no, you don’t. We might suggest things that are helpful for some people and are less helpful for others.”

Dr. Kelly said she worries that “there are snake oil salesmen and cons out there who will gladly take your money. These may be smart people, capable of doing very high-level testing, and even producing very detailed and accurate results, but that doesn’t mean we know what to do with them.”

She hopes to see a microbiome-based diagnostic test in the future, particularly if the ability to therapeutically manipulate the gut microbiome in various diseases becomes a reality.
 

Educate Clinicians, Companies

More education is needed on the subject, so we can become “microbial clinicians,” Dr. Kao said.

“The microbiome never came up when I was going through my medical education,” she said. But we, and the next generation of physicians, “need to at least be able to understand the basics.

“Hopefully, one day, we will be in a position where we can have meaningful interpretations of the test results and make some kind of meaningful dietary interventions,” Dr. Kao added.

As for clinicians who are currently ordering these tests and products directly from the DTC companies, Dr. Kao said, “I roll my eyes.”

Dr. Ghannoum reiterated that companies offering microbiome tests and products also need to be educated and encouraged to use systematic approaches to product development and interpretation.

“Companies should be open to calls from clinicians and be ready to explain findings on a report, as well as the basis for any recommendations,” he said.

Dr. von Rosenvinge, Dr. Kao, and Dr. Kelly had no relevant conflicts of interest. Dr. Ghannoum is a cofounder of BIOHM.

A version of this article appeared on Medscape.com.

The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may lead to an increased risk for aspiration pneumonia after endoscopic procedures, according to a new large population-based study.

In June 2023, the American Society of Anesthesiologists (ASA) recommended holding GLP-1 RAs before an endoscopic or surgical procedure to reduce the risk for complications associated with anesthesia and delayed stomach emptying.

In response, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures.

“It is known that GLP-1 RAs significantly reduce the motility of the stomach and small bowel. As more and more patients are being started on GLP-1 RAs at higher doses and longer half-life, the question became whether the current recommended fasting durations are enough to reasonably assume the stomach is empty prior to procedures that require sedation,” said senior author Ali Rezaie, MD, medical director of the GI Motility Program at Cedars-Sinai Medical Center in Los Angeles.

“We wanted to see if these medications in fact increased the chance of aspiration before the ASA suggestion went into effect,” he said. “However, this is not an easy task, as aspiration is a rare event and a large sample size is needed to confidently answer that question. That is why we evaluated nearly 1 million cases.”

The study was published online in Gastroenterology.
 

Analyzing GLP-1 RA Use

Dr. Rezaie and colleagues conducted a population-based, retrospective cohort study of the TriNetX dataset, which includes 114 million deidentified individual health records from 80 healthcare organizations. The research team analyzed nearly 1 million records for adult patients between ages 21 and 70 who underwent upper and lower endoscopies between January 2018 and December 2020.

Rezaie_Ali_CA_web.jpg

The researchers defined GLP-1 RA users as those who had the medication for more than 6 months and two or more refills within 6 months before the procedure. They adjusted for 59 factors that could affect gut motility or aspiration risks, such as obesity, numerous chronic diseases, and dozens of medications. The primary outcome was aspiration pneumonia within a month after the procedure.

Among 963,184 patients who underwent endoscopy, 46,935 (4.9%) were considered GLP-1 RA users. Among those, 20,099 GLP-1 RA users met the inclusion criteria and had their results compared with non-GLP-1 RA users.

After propensity score matching for the 59 potential confounders, GLP-1 RA use had a higher incidence rate of aspiration pneumonia (0.83% vs 0.63%) and was associated with a significantly higher risk for aspiration pneumonia, with a hazard ratio (HR) of 1.33.

An even higher risk was seen among patients with propofol-assisted endoscopies (HR, 1.49) but not among those without propofol (HR, 1.31).

In a subgroup analysis based on endoscopy type, an elevated risk was observed among patients who underwent upper endoscopy (HR, 1.82) and combined upper and lower endoscopy (HR, 2.26) but not lower endoscopy (HR, 0.56).

“The results were not necessarily surprising given the mechanism of action of GLP-1 RAs. However, for the first time, this was shown with a clinically relevant outcome, such as aspiration pneumonia,” Dr. Rezaie said. “Aspiration during sedation can have devastating consequences, and the 0.2% difference in risk of aspiration can have a significant effect on healthcare as well.”

More than 20 million endoscopies are performed across the United States annually. Based on the assumption that about 3% of those patients are taking GLP-1 RAs, about 1200 aspiration cases per year can be prevented by raising awareness, he said.
 

Considering Next Steps

The varying risk profiles observed with separate sedation and endoscopy types point to a need for more tailored guidance in managing GLP-1 RA use before a procedure, the study authors wrote.

Although holding the medications before endoscopy may disrupt diabetes management, the potential increased risk for aspiration could justify a change in practice, particularly for upper endoscopy and propofol-associated procedures, they added.

At the same time, additional studies are needed to understand the optimal drug withholding windows before endoscopies and other procedures, they concluded.

“We will need more data on what is the optimal duration of holding GLP-1 RAs,” Dr. Rezaie said. “But given our data and current ASA guidance, stopping these medications prior to elective procedures is the safe thing to do.”

For now, AGA guidance remains the same as offered in the November 2023 update, suggesting an individual approach for each patient on a GLP-1 RA rather than a “blanket statement” on how to manage all patients taking these medications.

“Overall, I believe that this study is important, but we require more high-level data to inform clinical decision-making regarding patients using GLP-1 receptor agonists prior to gastrointestinal endoscopy,” said Andrew Y. Wang, MD, AGAF, chief of gastroenterology and hepatology and director of interventional endoscopy at the University of Virginia in Charlottesville.

Dr. Wang, who wasn’t involved with this study, coauthored the AGA rapid clinical practice update. He and colleagues advised continuing with a procedure as planned for patients on GLP-1 RAs who followed standard preprocedure fasting instructions and didn’t have nausea, vomiting, dyspepsia, or abdominal distention.

Wang_Andrew_VA_web.jpg

A version of this article appeared on Medscape.com.

The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may lead to an increased risk for aspiration pneumonia after endoscopic procedures, according to a new large population-based study.

In June 2023, the American Society of Anesthesiologists (ASA) recommended holding GLP-1 RAs before an endoscopic or surgical procedure to reduce the risk for complications associated with anesthesia and delayed stomach emptying.

In response, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures.

“It is known that GLP-1 RAs significantly reduce the motility of the stomach and small bowel. As more and more patients are being started on GLP-1 RAs at higher doses and longer half-life, the question became whether the current recommended fasting durations are enough to reasonably assume the stomach is empty prior to procedures that require sedation,” said senior author Ali Rezaie, MD, medical director of the GI Motility Program at Cedars-Sinai Medical Center in Los Angeles.

“We wanted to see if these medications in fact increased the chance of aspiration before the ASA suggestion went into effect,” he said. “However, this is not an easy task, as aspiration is a rare event and a large sample size is needed to confidently answer that question. That is why we evaluated nearly 1 million cases.”

The study was published online in Gastroenterology.
 

Analyzing GLP-1 RA Use

Dr. Rezaie and colleagues conducted a population-based, retrospective cohort study of the TriNetX dataset, which includes 114 million deidentified individual health records from 80 healthcare organizations. The research team analyzed nearly 1 million records for adult patients between ages 21 and 70 who underwent upper and lower endoscopies between January 2018 and December 2020.

Rezaie_Ali_CA_web.jpg

The researchers defined GLP-1 RA users as those who had the medication for more than 6 months and two or more refills within 6 months before the procedure. They adjusted for 59 factors that could affect gut motility or aspiration risks, such as obesity, numerous chronic diseases, and dozens of medications. The primary outcome was aspiration pneumonia within a month after the procedure.

Among 963,184 patients who underwent endoscopy, 46,935 (4.9%) were considered GLP-1 RA users. Among those, 20,099 GLP-1 RA users met the inclusion criteria and had their results compared with non-GLP-1 RA users.

After propensity score matching for the 59 potential confounders, GLP-1 RA use had a higher incidence rate of aspiration pneumonia (0.83% vs 0.63%) and was associated with a significantly higher risk for aspiration pneumonia, with a hazard ratio (HR) of 1.33.

An even higher risk was seen among patients with propofol-assisted endoscopies (HR, 1.49) but not among those without propofol (HR, 1.31).

In a subgroup analysis based on endoscopy type, an elevated risk was observed among patients who underwent upper endoscopy (HR, 1.82) and combined upper and lower endoscopy (HR, 2.26) but not lower endoscopy (HR, 0.56).

“The results were not necessarily surprising given the mechanism of action of GLP-1 RAs. However, for the first time, this was shown with a clinically relevant outcome, such as aspiration pneumonia,” Dr. Rezaie said. “Aspiration during sedation can have devastating consequences, and the 0.2% difference in risk of aspiration can have a significant effect on healthcare as well.”

More than 20 million endoscopies are performed across the United States annually. Based on the assumption that about 3% of those patients are taking GLP-1 RAs, about 1200 aspiration cases per year can be prevented by raising awareness, he said.
 

Considering Next Steps

The varying risk profiles observed with separate sedation and endoscopy types point to a need for more tailored guidance in managing GLP-1 RA use before a procedure, the study authors wrote.

Although holding the medications before endoscopy may disrupt diabetes management, the potential increased risk for aspiration could justify a change in practice, particularly for upper endoscopy and propofol-associated procedures, they added.

At the same time, additional studies are needed to understand the optimal drug withholding windows before endoscopies and other procedures, they concluded.

“We will need more data on what is the optimal duration of holding GLP-1 RAs,” Dr. Rezaie said. “But given our data and current ASA guidance, stopping these medications prior to elective procedures is the safe thing to do.”

For now, AGA guidance remains the same as offered in the November 2023 update, suggesting an individual approach for each patient on a GLP-1 RA rather than a “blanket statement” on how to manage all patients taking these medications.

“Overall, I believe that this study is important, but we require more high-level data to inform clinical decision-making regarding patients using GLP-1 receptor agonists prior to gastrointestinal endoscopy,” said Andrew Y. Wang, MD, AGAF, chief of gastroenterology and hepatology and director of interventional endoscopy at the University of Virginia in Charlottesville.

Dr. Wang, who wasn’t involved with this study, coauthored the AGA rapid clinical practice update. He and colleagues advised continuing with a procedure as planned for patients on GLP-1 RAs who followed standard preprocedure fasting instructions and didn’t have nausea, vomiting, dyspepsia, or abdominal distention.

Wang_Andrew_VA_web.jpg

A version of this article appeared on Medscape.com.

The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may lead to an increased risk for aspiration pneumonia after endoscopic procedures, according to a new large population-based study.

In June 2023, the American Society of Anesthesiologists (ASA) recommended holding GLP-1 RAs before an endoscopic or surgical procedure to reduce the risk for complications associated with anesthesia and delayed stomach emptying.

In response, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures.

“It is known that GLP-1 RAs significantly reduce the motility of the stomach and small bowel. As more and more patients are being started on GLP-1 RAs at higher doses and longer half-life, the question became whether the current recommended fasting durations are enough to reasonably assume the stomach is empty prior to procedures that require sedation,” said senior author Ali Rezaie, MD, medical director of the GI Motility Program at Cedars-Sinai Medical Center in Los Angeles.

“We wanted to see if these medications in fact increased the chance of aspiration before the ASA suggestion went into effect,” he said. “However, this is not an easy task, as aspiration is a rare event and a large sample size is needed to confidently answer that question. That is why we evaluated nearly 1 million cases.”

The study was published online in Gastroenterology.
 

Analyzing GLP-1 RA Use

Dr. Rezaie and colleagues conducted a population-based, retrospective cohort study of the TriNetX dataset, which includes 114 million deidentified individual health records from 80 healthcare organizations. The research team analyzed nearly 1 million records for adult patients between ages 21 and 70 who underwent upper and lower endoscopies between January 2018 and December 2020.

Rezaie_Ali_CA_web.jpg

The researchers defined GLP-1 RA users as those who had the medication for more than 6 months and two or more refills within 6 months before the procedure. They adjusted for 59 factors that could affect gut motility or aspiration risks, such as obesity, numerous chronic diseases, and dozens of medications. The primary outcome was aspiration pneumonia within a month after the procedure.

Among 963,184 patients who underwent endoscopy, 46,935 (4.9%) were considered GLP-1 RA users. Among those, 20,099 GLP-1 RA users met the inclusion criteria and had their results compared with non-GLP-1 RA users.

After propensity score matching for the 59 potential confounders, GLP-1 RA use had a higher incidence rate of aspiration pneumonia (0.83% vs 0.63%) and was associated with a significantly higher risk for aspiration pneumonia, with a hazard ratio (HR) of 1.33.

An even higher risk was seen among patients with propofol-assisted endoscopies (HR, 1.49) but not among those without propofol (HR, 1.31).

In a subgroup analysis based on endoscopy type, an elevated risk was observed among patients who underwent upper endoscopy (HR, 1.82) and combined upper and lower endoscopy (HR, 2.26) but not lower endoscopy (HR, 0.56).

“The results were not necessarily surprising given the mechanism of action of GLP-1 RAs. However, for the first time, this was shown with a clinically relevant outcome, such as aspiration pneumonia,” Dr. Rezaie said. “Aspiration during sedation can have devastating consequences, and the 0.2% difference in risk of aspiration can have a significant effect on healthcare as well.”

More than 20 million endoscopies are performed across the United States annually. Based on the assumption that about 3% of those patients are taking GLP-1 RAs, about 1200 aspiration cases per year can be prevented by raising awareness, he said.
 

Considering Next Steps

The varying risk profiles observed with separate sedation and endoscopy types point to a need for more tailored guidance in managing GLP-1 RA use before a procedure, the study authors wrote.

Although holding the medications before endoscopy may disrupt diabetes management, the potential increased risk for aspiration could justify a change in practice, particularly for upper endoscopy and propofol-associated procedures, they added.

At the same time, additional studies are needed to understand the optimal drug withholding windows before endoscopies and other procedures, they concluded.

“We will need more data on what is the optimal duration of holding GLP-1 RAs,” Dr. Rezaie said. “But given our data and current ASA guidance, stopping these medications prior to elective procedures is the safe thing to do.”

For now, AGA guidance remains the same as offered in the November 2023 update, suggesting an individual approach for each patient on a GLP-1 RA rather than a “blanket statement” on how to manage all patients taking these medications.

“Overall, I believe that this study is important, but we require more high-level data to inform clinical decision-making regarding patients using GLP-1 receptor agonists prior to gastrointestinal endoscopy,” said Andrew Y. Wang, MD, AGAF, chief of gastroenterology and hepatology and director of interventional endoscopy at the University of Virginia in Charlottesville.

Dr. Wang, who wasn’t involved with this study, coauthored the AGA rapid clinical practice update. He and colleagues advised continuing with a procedure as planned for patients on GLP-1 RAs who followed standard preprocedure fasting instructions and didn’t have nausea, vomiting, dyspepsia, or abdominal distention.

Wang_Andrew_VA_web.jpg

A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the subcutaneous administration of vedolizumab (Entyvio) for maintenance therapy in adults with moderately to severely active Crohn’s disease (CD) after induction therapy with intravenous (IV) vedolizumab. 

The move follows the FDA’s approval last year of subcutaneous vedolizumab for maintenance treatment of adults with moderately to severely active ulcerative colitis (UC). 

The humanized immunoglobulin G1 monoclonal antibody is available as a single-dose prefilled pen (Entyvio Pen).

The FDA first approved the IV formulation of the biologic in 2014 for patients with moderate to severe UC and CD who cannot tolerate other therapies or in whom such therapies have failed. 

The approval of subcutaneous vedolizumab for maintenance treatment of CD is based on the phase 3, randomized, double-blind, placebo-controlled VISIBLE 2 trial.

The trial enrolled 409 adult patients with moderately to severely active CD who had clinical response at week 6 following two doses of open-label IV vedolizumab at weeks 0 and 2. 

At week 6, they were randomly allocated in a 2:1 ratio to receive vedolizumab 108 mg administered by subcutaneous injection or placebo every 2 weeks. The primary endpoint was clinical remission at week 52, which was defined as a total Crohn’s Disease Activity Index score ≤ 150.

The results showed that significantly more patients receiving subcutaneous vedolizumab than placebo achieved long-term clinical remission (48% vs 34%; P < .01), the company said in a news release. 

The safety profile of subcutaneous vedolizumab is generally consistent with the known safety profile of IV vedolizumab, with the addition of injection-site reactions (including injection-site erythema, rash, pruritus, swelling, bruising, hematoma, pain, urticaria, and edema).

“Crohn’s disease is a complex and usually progressive disease for which an appropriate management plan is critical. My primary goal as a clinician is always to get patients to achieve remission,” Timothy Ritter, MD, senior medical director, GI Alliance Research, and assistant professor of medicine, Burnett School of Medicine at TCU, Fort Worth, Texas, said in the news release.

Ritter_Timothy_TX_web.jpg

A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the subcutaneous administration of vedolizumab (Entyvio) for maintenance therapy in adults with moderately to severely active Crohn’s disease (CD) after induction therapy with intravenous (IV) vedolizumab. 

The move follows the FDA’s approval last year of subcutaneous vedolizumab for maintenance treatment of adults with moderately to severely active ulcerative colitis (UC). 

The humanized immunoglobulin G1 monoclonal antibody is available as a single-dose prefilled pen (Entyvio Pen).

The FDA first approved the IV formulation of the biologic in 2014 for patients with moderate to severe UC and CD who cannot tolerate other therapies or in whom such therapies have failed. 

The approval of subcutaneous vedolizumab for maintenance treatment of CD is based on the phase 3, randomized, double-blind, placebo-controlled VISIBLE 2 trial.

The trial enrolled 409 adult patients with moderately to severely active CD who had clinical response at week 6 following two doses of open-label IV vedolizumab at weeks 0 and 2. 

At week 6, they were randomly allocated in a 2:1 ratio to receive vedolizumab 108 mg administered by subcutaneous injection or placebo every 2 weeks. The primary endpoint was clinical remission at week 52, which was defined as a total Crohn’s Disease Activity Index score ≤ 150.

The results showed that significantly more patients receiving subcutaneous vedolizumab than placebo achieved long-term clinical remission (48% vs 34%; P < .01), the company said in a news release. 

The safety profile of subcutaneous vedolizumab is generally consistent with the known safety profile of IV vedolizumab, with the addition of injection-site reactions (including injection-site erythema, rash, pruritus, swelling, bruising, hematoma, pain, urticaria, and edema).

“Crohn’s disease is a complex and usually progressive disease for which an appropriate management plan is critical. My primary goal as a clinician is always to get patients to achieve remission,” Timothy Ritter, MD, senior medical director, GI Alliance Research, and assistant professor of medicine, Burnett School of Medicine at TCU, Fort Worth, Texas, said in the news release.

Ritter_Timothy_TX_web.jpg

A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the subcutaneous administration of vedolizumab (Entyvio) for maintenance therapy in adults with moderately to severely active Crohn’s disease (CD) after induction therapy with intravenous (IV) vedolizumab. 

The move follows the FDA’s approval last year of subcutaneous vedolizumab for maintenance treatment of adults with moderately to severely active ulcerative colitis (UC). 

The humanized immunoglobulin G1 monoclonal antibody is available as a single-dose prefilled pen (Entyvio Pen).

The FDA first approved the IV formulation of the biologic in 2014 for patients with moderate to severe UC and CD who cannot tolerate other therapies or in whom such therapies have failed. 

The approval of subcutaneous vedolizumab for maintenance treatment of CD is based on the phase 3, randomized, double-blind, placebo-controlled VISIBLE 2 trial.

The trial enrolled 409 adult patients with moderately to severely active CD who had clinical response at week 6 following two doses of open-label IV vedolizumab at weeks 0 and 2. 

At week 6, they were randomly allocated in a 2:1 ratio to receive vedolizumab 108 mg administered by subcutaneous injection or placebo every 2 weeks. The primary endpoint was clinical remission at week 52, which was defined as a total Crohn’s Disease Activity Index score ≤ 150.

The results showed that significantly more patients receiving subcutaneous vedolizumab than placebo achieved long-term clinical remission (48% vs 34%; P < .01), the company said in a news release. 

The safety profile of subcutaneous vedolizumab is generally consistent with the known safety profile of IV vedolizumab, with the addition of injection-site reactions (including injection-site erythema, rash, pruritus, swelling, bruising, hematoma, pain, urticaria, and edema).

“Crohn’s disease is a complex and usually progressive disease for which an appropriate management plan is critical. My primary goal as a clinician is always to get patients to achieve remission,” Timothy Ritter, MD, senior medical director, GI Alliance Research, and assistant professor of medicine, Burnett School of Medicine at TCU, Fort Worth, Texas, said in the news release.

Ritter_Timothy_TX_web.jpg

A version of this article appeared on Medscape.com.

Last year, I concluded a commentary for this news organization on colorectal cancer (CRC) screening guidelines by stating that between stool-based tests, flexible sigmoidoscopy, and colonoscopy, “the best screening test is the test that gets done.” But should that maxim apply to the new blood-based screening test, Guardant Health Shield? This proprietary test, which costs $895 and is not generally covered by insurance, identifies alterations in cell-free DNA that are characteristic of CRC.

Shield’s test characteristics were recently evaluated in a prospective study of more than 10,000 adults aged 45-84 at average risk for CRC. The test had an 87.5% sensitivity for stage I, II, or III colorectal cancer but only a 13% sensitivity for advanced precancerous lesions. Test specificity was 89.6%, meaning that about 1 in 10 participants without CRC or advanced precancerous lesions on colonoscopy had a false-positive result.

Although the Shield blood test has a higher rate of false positives than the traditional fecal immunochemical test (FIT) and lower sensitivity and specificity than a multitarget stool DNA (FIT-DNA) test designed to improve on Cologuard, it meets the previously established criteria set forth by the Centers for Medicare & Medicaid Services (CMS) to be covered for Medicare beneficiaries at 3-year intervals, pending FDA approval. If public and private payers start covering Shield alongside other CRC screening tests, it presents an opportunity for primary care physicians to reach the approximately 3 in 10 adults between ages 45 and 75 who are not being routinely screened.

A big concern, however, is that the availability of a blood test may cause patients who would have otherwise been screened with colonoscopy or stool tests to switch to the blood test. A cost-effectiveness analysis found that offering a blood test to patients who decline screening colonoscopy saves additional lives, but at the cost of more than $377,000 per life-year gained. Another study relying on three microsimulation models previously utilized by the US Preventive Services Task Force (USPSTF) found that annual FIT results in more life-years gained at substantially lower cost than blood-based screening every 3 years “even when uptake of blood-based screening was 20 percentage points higher than uptake of FIT.” As a result, a multidisciplinary expert panel concluded that blood-based screening should not substitute for established CRC screening tests, but instead be offered only to patients who decline those tests.

In practice, this will increase the complexity of the CRC screening conversations we have with patients. We will need to be clear that the blood test is not yet endorsed by the USPSTF or any major guideline group and is a second-line test that will miss most precancerous polyps. As with the stool tests, it is essential to emphasize that a positive result must be followed by diagnostic colonoscopy. To addend the cancer screening maxim I mentioned before, the blood test is not the best test for CRC, but it’s probably better than no test at all.

Dr. Lin is a family physician and associate director, Family Medicine Residency Program, Lancaster General Hospital, Lancaster, Pennsylvania. He blogs at Common Sense Family Doctor.

A version of this article appeared on Medscape.com.

Last year, I concluded a commentary for this news organization on colorectal cancer (CRC) screening guidelines by stating that between stool-based tests, flexible sigmoidoscopy, and colonoscopy, “the best screening test is the test that gets done.” But should that maxim apply to the new blood-based screening test, Guardant Health Shield? This proprietary test, which costs $895 and is not generally covered by insurance, identifies alterations in cell-free DNA that are characteristic of CRC.

Shield’s test characteristics were recently evaluated in a prospective study of more than 10,000 adults aged 45-84 at average risk for CRC. The test had an 87.5% sensitivity for stage I, II, or III colorectal cancer but only a 13% sensitivity for advanced precancerous lesions. Test specificity was 89.6%, meaning that about 1 in 10 participants without CRC or advanced precancerous lesions on colonoscopy had a false-positive result.

Although the Shield blood test has a higher rate of false positives than the traditional fecal immunochemical test (FIT) and lower sensitivity and specificity than a multitarget stool DNA (FIT-DNA) test designed to improve on Cologuard, it meets the previously established criteria set forth by the Centers for Medicare & Medicaid Services (CMS) to be covered for Medicare beneficiaries at 3-year intervals, pending FDA approval. If public and private payers start covering Shield alongside other CRC screening tests, it presents an opportunity for primary care physicians to reach the approximately 3 in 10 adults between ages 45 and 75 who are not being routinely screened.

A big concern, however, is that the availability of a blood test may cause patients who would have otherwise been screened with colonoscopy or stool tests to switch to the blood test. A cost-effectiveness analysis found that offering a blood test to patients who decline screening colonoscopy saves additional lives, but at the cost of more than $377,000 per life-year gained. Another study relying on three microsimulation models previously utilized by the US Preventive Services Task Force (USPSTF) found that annual FIT results in more life-years gained at substantially lower cost than blood-based screening every 3 years “even when uptake of blood-based screening was 20 percentage points higher than uptake of FIT.” As a result, a multidisciplinary expert panel concluded that blood-based screening should not substitute for established CRC screening tests, but instead be offered only to patients who decline those tests.

In practice, this will increase the complexity of the CRC screening conversations we have with patients. We will need to be clear that the blood test is not yet endorsed by the USPSTF or any major guideline group and is a second-line test that will miss most precancerous polyps. As with the stool tests, it is essential to emphasize that a positive result must be followed by diagnostic colonoscopy. To addend the cancer screening maxim I mentioned before, the blood test is not the best test for CRC, but it’s probably better than no test at all.

Dr. Lin is a family physician and associate director, Family Medicine Residency Program, Lancaster General Hospital, Lancaster, Pennsylvania. He blogs at Common Sense Family Doctor.

A version of this article appeared on Medscape.com.

Last year, I concluded a commentary for this news organization on colorectal cancer (CRC) screening guidelines by stating that between stool-based tests, flexible sigmoidoscopy, and colonoscopy, “the best screening test is the test that gets done.” But should that maxim apply to the new blood-based screening test, Guardant Health Shield? This proprietary test, which costs $895 and is not generally covered by insurance, identifies alterations in cell-free DNA that are characteristic of CRC.

Shield’s test characteristics were recently evaluated in a prospective study of more than 10,000 adults aged 45-84 at average risk for CRC. The test had an 87.5% sensitivity for stage I, II, or III colorectal cancer but only a 13% sensitivity for advanced precancerous lesions. Test specificity was 89.6%, meaning that about 1 in 10 participants without CRC or advanced precancerous lesions on colonoscopy had a false-positive result.

Although the Shield blood test has a higher rate of false positives than the traditional fecal immunochemical test (FIT) and lower sensitivity and specificity than a multitarget stool DNA (FIT-DNA) test designed to improve on Cologuard, it meets the previously established criteria set forth by the Centers for Medicare & Medicaid Services (CMS) to be covered for Medicare beneficiaries at 3-year intervals, pending FDA approval. If public and private payers start covering Shield alongside other CRC screening tests, it presents an opportunity for primary care physicians to reach the approximately 3 in 10 adults between ages 45 and 75 who are not being routinely screened.

A big concern, however, is that the availability of a blood test may cause patients who would have otherwise been screened with colonoscopy or stool tests to switch to the blood test. A cost-effectiveness analysis found that offering a blood test to patients who decline screening colonoscopy saves additional lives, but at the cost of more than $377,000 per life-year gained. Another study relying on three microsimulation models previously utilized by the US Preventive Services Task Force (USPSTF) found that annual FIT results in more life-years gained at substantially lower cost than blood-based screening every 3 years “even when uptake of blood-based screening was 20 percentage points higher than uptake of FIT.” As a result, a multidisciplinary expert panel concluded that blood-based screening should not substitute for established CRC screening tests, but instead be offered only to patients who decline those tests.

In practice, this will increase the complexity of the CRC screening conversations we have with patients. We will need to be clear that the blood test is not yet endorsed by the USPSTF or any major guideline group and is a second-line test that will miss most precancerous polyps. As with the stool tests, it is essential to emphasize that a positive result must be followed by diagnostic colonoscopy. To addend the cancer screening maxim I mentioned before, the blood test is not the best test for CRC, but it’s probably better than no test at all.

Dr. Lin is a family physician and associate director, Family Medicine Residency Program, Lancaster General Hospital, Lancaster, Pennsylvania. He blogs at Common Sense Family Doctor.

A version of this article appeared on Medscape.com.

PARIS — Irritable bowel syndrome (IBS) is a common brain-gut axis disorder, and patients are often dissatisfied with conventional treatments.

The role of the microbiota in IBS is now well established, and patients frequently take probiotics on their own initiative or on the advice of a physician or pharmacist. However, not all probiotics have equal efficacy, so which ones should be recommended?

Jean-Marc Sabaté, MD, PhD, a gastroenterologist at Avicenne Hospital in Bobigny, France, shared insights about probiotics at the Francophone Days of Hepatology, Gastroenterology, and Digestive Oncology.

IBS, according to the Rome IV symptom-based classification, is a “disorder of brain-gut axis interactions” with a prevalence of about 4% in the adult population. In France, during an average care pathway of about 8 years, patients try an average of five therapeutic strategies (and as many as 11), including antispasmodics (85%), diets (78%), and probiotics. In addition, 66.4% of patients had either taken or were taking probiotics at the time of a recent survey.

While the 2022 recommendations from the American College of Gastroenterology on the diagnosis and management of IBS do not support the use of probiotics for overall symptom relief — a recommendation for which they cite a low level of evidence — “there is nevertheless a rationale for prescribing probiotics in IBS due to the significant role of the microbiota (or dysbiosis) in this condition,” said Dr. Sabaté.
 

Microbiota in IBS 

Evidence indicating that antibiotics exacerbate IBS symptoms and revealing chronic bacterial overgrowth in the small intestine of patients with IBS supports the role of the microbiota. Studies using a molecular approach (16s rRNA) have settled the debate, confirming differences in the intestinal flora between patients with IBS and healthy subjects. Data also indicate differences in flora between patient subtypes, such as an increased Firmicutes to Bacteroidetes ratio. However, one subgroup, which can represent as much as a third of patients, seems to harbor a “normal” microbiota. 

Nonetheless, the microbiota plays a significant role in IBS. A Swedish study highlighted the influence of bacterial enterotypes on transit type associated with IBS and symptom severity, independent of diet composition or medication use. 

This dysbiosis could play a significant role as it interacts with other mechanisms involved in IBS, including changes in intestinal motility related to diet (related to fermentable carbohydrates, for example). Moreover, the microbiota seems to induce a low level of immune activation in patients with IBS, leading to microinflammation and increased intestinal permeability, especially after an infection.

Furthermore, alterations in the regulation of bile acid deconjugation by the microbiota partly explain the frequency and consistency of stools in diarrhea-predominant IBS patients.

In addition, colonic gas production is higher in these patients. Those complaining of flatulence have poor tolerance to intestinal gases after a flatulent meal, associated with microbiota instability.

Data regarding the interaction between the microbiota and central mechanisms mainly come from animal studies. In rodents, microbiota constituents seem to affect brain development, function, and morphology. Emotional and physical traumas during childhood appear to be risk factors. Moreover, even brief exposure to broad-spectrum antibiotics in neonates could cause subsequent visceral hypersensitivity.

Lastly, the role of the microbiota in changes in medullary pain control after visceral stimulation (eg, rectal distension) has still not been demonstrated in humans.
 

Recent Guideline 

In its February 2023 Global Guideline “Probiotics and Prebiotics” for IBS, the World Gastroenterology Organization looked at the level of evidence for probiotics.

Three strains, as well as a combination of several strains, were supported by level 2 evidence, meaning at least two randomized studies with converging results. These are Bifidobacterium bifidum MIMBb75, which improves overall symptoms and quality of life; Lactobacillus plantarum 299v (DSM 9843), which acts on the severity of abdominal pain and bloating; and B infantis 35624 (new name: B longum 35624), which improves the overall assessment of IBS symptoms, as does the multistrain product containing L rhamnosus GG, L rhamnosus LC705, Propionibacterium freudenreichii ssp shermanii JS DSM 7067, and B animalis ssp lactis B012 DSM 15954.
 

Efficacy and Availability 

Probiotics belonging to the category of dietary supplements or medical devices are not required to provide evidence for a mechanism of action or even efficacy to be marketed. Thus, for most probiotics sold, there are no human or even animal studies available.

Dr. Sabaté proposed a choice of probiotics based on the literature and the presence of at least one randomized placebo-controlled trial conducted in patients with IBS showing positive results.

“Probiotic efficacy largely depends on the bacterial species, strain, and clinical situation treated. Only probiotics with demonstrated clinical efficacy in randomized placebo-controlled trials should be recommended,” he emphasized. The parameters that can be improved include symptom severity, quality of life, abdominal pain, and bloating.
 

Effective Probiotics 

B longum 35624, which was developed with researchers from University College Cork in Ireland, is probably the most studied in animals and humans. Research has encompassed the mechanistic, clinical, and safety aspects of the probiotic. It has shown good results on the IBS-Symptom Severity Score (SSS), quality of life, abdominal pain, bowel disturbances, and bloating. The treatment duration in studies is 4-8 weeks.

L plantarum 299v (DSM 9843) affects the frequency of abdominal pain and pain score. The treatment duration in studies is 4 weeks.

The multistrain product that includes L plantarum CECT 7484/L plantarum CECT 7485/ Pediococcus acidilactici CECT 7483 allows for an improvement in quality of life and anxiety related to digestive symptoms. No positive effect has been described on digestive symptoms, especially diarrhea. The treatment duration is 6 weeks.

B bifidum MIMBb75 (both normal and heat-inactivated forms) is beneficial for pain, the composite IBS-SSS score, and quality of life. The treatment duration is 4-8 weeks.

“Except for the multistrain combination, which is more suited to patients with diarrhea-predominant IBS, the other three probiotics can be prescribed regardless of the IBS subtype,” said Dr. Sabaté. “Treatment durations are typically 4 weeks, but it is possible to continue up to 8 weeks, which is the maximum duration of these studies. In practice, there are no tolerance issues with probiotics prescribed for IBS based on the literature. These should be tested under the conditions and for the duration of the published studies and should only be continued if there is individual benefit on symptoms or quality of life.”

Note that microbiota analyses conducted for individual purposes are of no help in choosing probiotics.
 

Mechanisms of Action 

In a murine model, but not in humans, some strains, especially L acidophilus NCFM, have shown an antinociceptive effect by inducing opioid and cannabinoid receptors.

Only in animals to date, L farciminis and B lactis CNCM I-2494 have shown prevention of induced hypersensitivity (ie, inhibition of the cytoskeleton contraction of colon epithelial cells and subsequent opening of tight junctions).

B infantis 35624 has an anti-inflammatory action by modifying the IL-10 and IL-12 cytokine ratio in animals and humans. It has an immunomodulatory action by increasing dendritic cells in the mucosa and decreasing Th1 and Th7 helper T cells.

B infantis 35624 and L farciminis are two strains that decrease visceral sensitivity in mice.

Escherichia coli Nissle 1917 acts on lipopeptide production with an antinociceptive effect, as observed in mice, by decreasing visceral sensitivity through calcium nociceptor flux blockade (action on GABA type B receptor).

Acting on dysbiosis by modifying fecal microbiota during probiotic intake is possible but depends on the probiotics, like B infantis 35624. In humans, B longum NCC 3001 could modify brain activations.

Dr. Sabaté disclosed financial relationships with Mayoly Spindler, Kyowa Kirin, Tillotts, Servier, Norgine, Biocodex, Merck, Viatris, Abivax, and Inventiva.

This story was translated from the Medscape French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

PARIS — Irritable bowel syndrome (IBS) is a common brain-gut axis disorder, and patients are often dissatisfied with conventional treatments.

The role of the microbiota in IBS is now well established, and patients frequently take probiotics on their own initiative or on the advice of a physician or pharmacist. However, not all probiotics have equal efficacy, so which ones should be recommended?

Jean-Marc Sabaté, MD, PhD, a gastroenterologist at Avicenne Hospital in Bobigny, France, shared insights about probiotics at the Francophone Days of Hepatology, Gastroenterology, and Digestive Oncology.

IBS, according to the Rome IV symptom-based classification, is a “disorder of brain-gut axis interactions” with a prevalence of about 4% in the adult population. In France, during an average care pathway of about 8 years, patients try an average of five therapeutic strategies (and as many as 11), including antispasmodics (85%), diets (78%), and probiotics. In addition, 66.4% of patients had either taken or were taking probiotics at the time of a recent survey.

While the 2022 recommendations from the American College of Gastroenterology on the diagnosis and management of IBS do not support the use of probiotics for overall symptom relief — a recommendation for which they cite a low level of evidence — “there is nevertheless a rationale for prescribing probiotics in IBS due to the significant role of the microbiota (or dysbiosis) in this condition,” said Dr. Sabaté.
 

Microbiota in IBS 

Evidence indicating that antibiotics exacerbate IBS symptoms and revealing chronic bacterial overgrowth in the small intestine of patients with IBS supports the role of the microbiota. Studies using a molecular approach (16s rRNA) have settled the debate, confirming differences in the intestinal flora between patients with IBS and healthy subjects. Data also indicate differences in flora between patient subtypes, such as an increased Firmicutes to Bacteroidetes ratio. However, one subgroup, which can represent as much as a third of patients, seems to harbor a “normal” microbiota. 

Nonetheless, the microbiota plays a significant role in IBS. A Swedish study highlighted the influence of bacterial enterotypes on transit type associated with IBS and symptom severity, independent of diet composition or medication use. 

This dysbiosis could play a significant role as it interacts with other mechanisms involved in IBS, including changes in intestinal motility related to diet (related to fermentable carbohydrates, for example). Moreover, the microbiota seems to induce a low level of immune activation in patients with IBS, leading to microinflammation and increased intestinal permeability, especially after an infection.

Furthermore, alterations in the regulation of bile acid deconjugation by the microbiota partly explain the frequency and consistency of stools in diarrhea-predominant IBS patients.

In addition, colonic gas production is higher in these patients. Those complaining of flatulence have poor tolerance to intestinal gases after a flatulent meal, associated with microbiota instability.

Data regarding the interaction between the microbiota and central mechanisms mainly come from animal studies. In rodents, microbiota constituents seem to affect brain development, function, and morphology. Emotional and physical traumas during childhood appear to be risk factors. Moreover, even brief exposure to broad-spectrum antibiotics in neonates could cause subsequent visceral hypersensitivity.

Lastly, the role of the microbiota in changes in medullary pain control after visceral stimulation (eg, rectal distension) has still not been demonstrated in humans.
 

Recent Guideline 

In its February 2023 Global Guideline “Probiotics and Prebiotics” for IBS, the World Gastroenterology Organization looked at the level of evidence for probiotics.

Three strains, as well as a combination of several strains, were supported by level 2 evidence, meaning at least two randomized studies with converging results. These are Bifidobacterium bifidum MIMBb75, which improves overall symptoms and quality of life; Lactobacillus plantarum 299v (DSM 9843), which acts on the severity of abdominal pain and bloating; and B infantis 35624 (new name: B longum 35624), which improves the overall assessment of IBS symptoms, as does the multistrain product containing L rhamnosus GG, L rhamnosus LC705, Propionibacterium freudenreichii ssp shermanii JS DSM 7067, and B animalis ssp lactis B012 DSM 15954.
 

Efficacy and Availability 

Probiotics belonging to the category of dietary supplements or medical devices are not required to provide evidence for a mechanism of action or even efficacy to be marketed. Thus, for most probiotics sold, there are no human or even animal studies available.

Dr. Sabaté proposed a choice of probiotics based on the literature and the presence of at least one randomized placebo-controlled trial conducted in patients with IBS showing positive results.

“Probiotic efficacy largely depends on the bacterial species, strain, and clinical situation treated. Only probiotics with demonstrated clinical efficacy in randomized placebo-controlled trials should be recommended,” he emphasized. The parameters that can be improved include symptom severity, quality of life, abdominal pain, and bloating.
 

Effective Probiotics 

B longum 35624, which was developed with researchers from University College Cork in Ireland, is probably the most studied in animals and humans. Research has encompassed the mechanistic, clinical, and safety aspects of the probiotic. It has shown good results on the IBS-Symptom Severity Score (SSS), quality of life, abdominal pain, bowel disturbances, and bloating. The treatment duration in studies is 4-8 weeks.

L plantarum 299v (DSM 9843) affects the frequency of abdominal pain and pain score. The treatment duration in studies is 4 weeks.

The multistrain product that includes L plantarum CECT 7484/L plantarum CECT 7485/ Pediococcus acidilactici CECT 7483 allows for an improvement in quality of life and anxiety related to digestive symptoms. No positive effect has been described on digestive symptoms, especially diarrhea. The treatment duration is 6 weeks.

B bifidum MIMBb75 (both normal and heat-inactivated forms) is beneficial for pain, the composite IBS-SSS score, and quality of life. The treatment duration is 4-8 weeks.

“Except for the multistrain combination, which is more suited to patients with diarrhea-predominant IBS, the other three probiotics can be prescribed regardless of the IBS subtype,” said Dr. Sabaté. “Treatment durations are typically 4 weeks, but it is possible to continue up to 8 weeks, which is the maximum duration of these studies. In practice, there are no tolerance issues with probiotics prescribed for IBS based on the literature. These should be tested under the conditions and for the duration of the published studies and should only be continued if there is individual benefit on symptoms or quality of life.”

Note that microbiota analyses conducted for individual purposes are of no help in choosing probiotics.
 

Mechanisms of Action 

In a murine model, but not in humans, some strains, especially L acidophilus NCFM, have shown an antinociceptive effect by inducing opioid and cannabinoid receptors.

Only in animals to date, L farciminis and B lactis CNCM I-2494 have shown prevention of induced hypersensitivity (ie, inhibition of the cytoskeleton contraction of colon epithelial cells and subsequent opening of tight junctions).

B infantis 35624 has an anti-inflammatory action by modifying the IL-10 and IL-12 cytokine ratio in animals and humans. It has an immunomodulatory action by increasing dendritic cells in the mucosa and decreasing Th1 and Th7 helper T cells.

B infantis 35624 and L farciminis are two strains that decrease visceral sensitivity in mice.

Escherichia coli Nissle 1917 acts on lipopeptide production with an antinociceptive effect, as observed in mice, by decreasing visceral sensitivity through calcium nociceptor flux blockade (action on GABA type B receptor).

Acting on dysbiosis by modifying fecal microbiota during probiotic intake is possible but depends on the probiotics, like B infantis 35624. In humans, B longum NCC 3001 could modify brain activations.

Dr. Sabaté disclosed financial relationships with Mayoly Spindler, Kyowa Kirin, Tillotts, Servier, Norgine, Biocodex, Merck, Viatris, Abivax, and Inventiva.

This story was translated from the Medscape French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

PARIS — Irritable bowel syndrome (IBS) is a common brain-gut axis disorder, and patients are often dissatisfied with conventional treatments.

The role of the microbiota in IBS is now well established, and patients frequently take probiotics on their own initiative or on the advice of a physician or pharmacist. However, not all probiotics have equal efficacy, so which ones should be recommended?

Jean-Marc Sabaté, MD, PhD, a gastroenterologist at Avicenne Hospital in Bobigny, France, shared insights about probiotics at the Francophone Days of Hepatology, Gastroenterology, and Digestive Oncology.

IBS, according to the Rome IV symptom-based classification, is a “disorder of brain-gut axis interactions” with a prevalence of about 4% in the adult population. In France, during an average care pathway of about 8 years, patients try an average of five therapeutic strategies (and as many as 11), including antispasmodics (85%), diets (78%), and probiotics. In addition, 66.4% of patients had either taken or were taking probiotics at the time of a recent survey.

While the 2022 recommendations from the American College of Gastroenterology on the diagnosis and management of IBS do not support the use of probiotics for overall symptom relief — a recommendation for which they cite a low level of evidence — “there is nevertheless a rationale for prescribing probiotics in IBS due to the significant role of the microbiota (or dysbiosis) in this condition,” said Dr. Sabaté.
 

Microbiota in IBS 

Evidence indicating that antibiotics exacerbate IBS symptoms and revealing chronic bacterial overgrowth in the small intestine of patients with IBS supports the role of the microbiota. Studies using a molecular approach (16s rRNA) have settled the debate, confirming differences in the intestinal flora between patients with IBS and healthy subjects. Data also indicate differences in flora between patient subtypes, such as an increased Firmicutes to Bacteroidetes ratio. However, one subgroup, which can represent as much as a third of patients, seems to harbor a “normal” microbiota. 

Nonetheless, the microbiota plays a significant role in IBS. A Swedish study highlighted the influence of bacterial enterotypes on transit type associated with IBS and symptom severity, independent of diet composition or medication use. 

This dysbiosis could play a significant role as it interacts with other mechanisms involved in IBS, including changes in intestinal motility related to diet (related to fermentable carbohydrates, for example). Moreover, the microbiota seems to induce a low level of immune activation in patients with IBS, leading to microinflammation and increased intestinal permeability, especially after an infection.

Furthermore, alterations in the regulation of bile acid deconjugation by the microbiota partly explain the frequency and consistency of stools in diarrhea-predominant IBS patients.

In addition, colonic gas production is higher in these patients. Those complaining of flatulence have poor tolerance to intestinal gases after a flatulent meal, associated with microbiota instability.

Data regarding the interaction between the microbiota and central mechanisms mainly come from animal studies. In rodents, microbiota constituents seem to affect brain development, function, and morphology. Emotional and physical traumas during childhood appear to be risk factors. Moreover, even brief exposure to broad-spectrum antibiotics in neonates could cause subsequent visceral hypersensitivity.

Lastly, the role of the microbiota in changes in medullary pain control after visceral stimulation (eg, rectal distension) has still not been demonstrated in humans.
 

Recent Guideline 

In its February 2023 Global Guideline “Probiotics and Prebiotics” for IBS, the World Gastroenterology Organization looked at the level of evidence for probiotics.

Three strains, as well as a combination of several strains, were supported by level 2 evidence, meaning at least two randomized studies with converging results. These are Bifidobacterium bifidum MIMBb75, which improves overall symptoms and quality of life; Lactobacillus plantarum 299v (DSM 9843), which acts on the severity of abdominal pain and bloating; and B infantis 35624 (new name: B longum 35624), which improves the overall assessment of IBS symptoms, as does the multistrain product containing L rhamnosus GG, L rhamnosus LC705, Propionibacterium freudenreichii ssp shermanii JS DSM 7067, and B animalis ssp lactis B012 DSM 15954.
 

Efficacy and Availability 

Probiotics belonging to the category of dietary supplements or medical devices are not required to provide evidence for a mechanism of action or even efficacy to be marketed. Thus, for most probiotics sold, there are no human or even animal studies available.

Dr. Sabaté proposed a choice of probiotics based on the literature and the presence of at least one randomized placebo-controlled trial conducted in patients with IBS showing positive results.

“Probiotic efficacy largely depends on the bacterial species, strain, and clinical situation treated. Only probiotics with demonstrated clinical efficacy in randomized placebo-controlled trials should be recommended,” he emphasized. The parameters that can be improved include symptom severity, quality of life, abdominal pain, and bloating.
 

Effective Probiotics 

B longum 35624, which was developed with researchers from University College Cork in Ireland, is probably the most studied in animals and humans. Research has encompassed the mechanistic, clinical, and safety aspects of the probiotic. It has shown good results on the IBS-Symptom Severity Score (SSS), quality of life, abdominal pain, bowel disturbances, and bloating. The treatment duration in studies is 4-8 weeks.

L plantarum 299v (DSM 9843) affects the frequency of abdominal pain and pain score. The treatment duration in studies is 4 weeks.

The multistrain product that includes L plantarum CECT 7484/L plantarum CECT 7485/ Pediococcus acidilactici CECT 7483 allows for an improvement in quality of life and anxiety related to digestive symptoms. No positive effect has been described on digestive symptoms, especially diarrhea. The treatment duration is 6 weeks.

B bifidum MIMBb75 (both normal and heat-inactivated forms) is beneficial for pain, the composite IBS-SSS score, and quality of life. The treatment duration is 4-8 weeks.

“Except for the multistrain combination, which is more suited to patients with diarrhea-predominant IBS, the other three probiotics can be prescribed regardless of the IBS subtype,” said Dr. Sabaté. “Treatment durations are typically 4 weeks, but it is possible to continue up to 8 weeks, which is the maximum duration of these studies. In practice, there are no tolerance issues with probiotics prescribed for IBS based on the literature. These should be tested under the conditions and for the duration of the published studies and should only be continued if there is individual benefit on symptoms or quality of life.”

Note that microbiota analyses conducted for individual purposes are of no help in choosing probiotics.
 

Mechanisms of Action 

In a murine model, but not in humans, some strains, especially L acidophilus NCFM, have shown an antinociceptive effect by inducing opioid and cannabinoid receptors.

Only in animals to date, L farciminis and B lactis CNCM I-2494 have shown prevention of induced hypersensitivity (ie, inhibition of the cytoskeleton contraction of colon epithelial cells and subsequent opening of tight junctions).

B infantis 35624 has an anti-inflammatory action by modifying the IL-10 and IL-12 cytokine ratio in animals and humans. It has an immunomodulatory action by increasing dendritic cells in the mucosa and decreasing Th1 and Th7 helper T cells.

B infantis 35624 and L farciminis are two strains that decrease visceral sensitivity in mice.

Escherichia coli Nissle 1917 acts on lipopeptide production with an antinociceptive effect, as observed in mice, by decreasing visceral sensitivity through calcium nociceptor flux blockade (action on GABA type B receptor).

Acting on dysbiosis by modifying fecal microbiota during probiotic intake is possible but depends on the probiotics, like B infantis 35624. In humans, B longum NCC 3001 could modify brain activations.

Dr. Sabaté disclosed financial relationships with Mayoly Spindler, Kyowa Kirin, Tillotts, Servier, Norgine, Biocodex, Merck, Viatris, Abivax, and Inventiva.

This story was translated from the Medscape French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the biosimilar ustekinumab-aekn (Selarsdi) for the treatment of moderate to severe plaque psoriasis and psoriatic arthritis in adults and pediatric patients aged 6 years or older.

This is the second ustekinumab biosimilar approved by the regulatory agency and is the second biosimilar approval in the United States for the Icelandic pharmaceutical company Alvotech in partnership with Teva Pharmaceuticals. 

Ustekinumab (Stelara) is a human monoclonal antibody targeting interleukin (IL)–12 and IL-23. The drug, manufactured by Johnson & Johnson, totaled nearly $7 billion in sales in 2023 alone, according a press release. 

“Bringing Selarsdi to market in the US early next year presents a significant opportunity to improve patient access to a vital biologic in inflammatory disease and contribute to the reduction of inflationary pressure in healthcare costs,” the chairman and CEO of Alvotech said in the release. 

The first ustekinumab biosimilar, ustekinumab-auub (Wezlana), was approved by the FDA in on October 31, 2023 and is interchangeable with the reference product. This allows pharmacists to substitute the biosimilar for the reference product without involving the prescribing clinician (according to state law). Besides psoriasis and psoriatic arthritis, ustekinumab-auub was also approved for treating moderate to severely active Crohn’s disease and ulcerative colitis. Ustekinumab-aekn does not have an interchangeability designation and was not approved for Crohn’s disease or ulcerative colitis. 

The approval of ustekinumab-aekn was based on two clinical studies. A randomized, double blind, multicenter, 52-week study of 581 patients with moderate to severe plaque psoriasis demonstrated that the biosimilar was as effective as the reference product, with equivalent safety and immunogenicity profiles. A phase 1, randomized, double-blind, single-dose, parallel-group, three-arm study also compared the pharmacokinetic profile of the biosimilar to ustekinumab in 294 healthy adults.

Ustekinumab-aekn is expected to be marketed in the United States on or after February 21, 2025 per a settlement and license agreement with Johnson & Johnson. 

A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the biosimilar ustekinumab-aekn (Selarsdi) for the treatment of moderate to severe plaque psoriasis and psoriatic arthritis in adults and pediatric patients aged 6 years or older.

This is the second ustekinumab biosimilar approved by the regulatory agency and is the second biosimilar approval in the United States for the Icelandic pharmaceutical company Alvotech in partnership with Teva Pharmaceuticals. 

Ustekinumab (Stelara) is a human monoclonal antibody targeting interleukin (IL)–12 and IL-23. The drug, manufactured by Johnson & Johnson, totaled nearly $7 billion in sales in 2023 alone, according a press release. 

“Bringing Selarsdi to market in the US early next year presents a significant opportunity to improve patient access to a vital biologic in inflammatory disease and contribute to the reduction of inflationary pressure in healthcare costs,” the chairman and CEO of Alvotech said in the release. 

The first ustekinumab biosimilar, ustekinumab-auub (Wezlana), was approved by the FDA in on October 31, 2023 and is interchangeable with the reference product. This allows pharmacists to substitute the biosimilar for the reference product without involving the prescribing clinician (according to state law). Besides psoriasis and psoriatic arthritis, ustekinumab-auub was also approved for treating moderate to severely active Crohn’s disease and ulcerative colitis. Ustekinumab-aekn does not have an interchangeability designation and was not approved for Crohn’s disease or ulcerative colitis. 

The approval of ustekinumab-aekn was based on two clinical studies. A randomized, double blind, multicenter, 52-week study of 581 patients with moderate to severe plaque psoriasis demonstrated that the biosimilar was as effective as the reference product, with equivalent safety and immunogenicity profiles. A phase 1, randomized, double-blind, single-dose, parallel-group, three-arm study also compared the pharmacokinetic profile of the biosimilar to ustekinumab in 294 healthy adults.

Ustekinumab-aekn is expected to be marketed in the United States on or after February 21, 2025 per a settlement and license agreement with Johnson & Johnson. 

A version of this article appeared on Medscape.com.

The US Food and Drug Administration (FDA) has approved the biosimilar ustekinumab-aekn (Selarsdi) for the treatment of moderate to severe plaque psoriasis and psoriatic arthritis in adults and pediatric patients aged 6 years or older.

This is the second ustekinumab biosimilar approved by the regulatory agency and is the second biosimilar approval in the United States for the Icelandic pharmaceutical company Alvotech in partnership with Teva Pharmaceuticals. 

Ustekinumab (Stelara) is a human monoclonal antibody targeting interleukin (IL)–12 and IL-23. The drug, manufactured by Johnson & Johnson, totaled nearly $7 billion in sales in 2023 alone, according a press release. 

“Bringing Selarsdi to market in the US early next year presents a significant opportunity to improve patient access to a vital biologic in inflammatory disease and contribute to the reduction of inflationary pressure in healthcare costs,” the chairman and CEO of Alvotech said in the release. 

The first ustekinumab biosimilar, ustekinumab-auub (Wezlana), was approved by the FDA in on October 31, 2023 and is interchangeable with the reference product. This allows pharmacists to substitute the biosimilar for the reference product without involving the prescribing clinician (according to state law). Besides psoriasis and psoriatic arthritis, ustekinumab-auub was also approved for treating moderate to severely active Crohn’s disease and ulcerative colitis. Ustekinumab-aekn does not have an interchangeability designation and was not approved for Crohn’s disease or ulcerative colitis. 

The approval of ustekinumab-aekn was based on two clinical studies. A randomized, double blind, multicenter, 52-week study of 581 patients with moderate to severe plaque psoriasis demonstrated that the biosimilar was as effective as the reference product, with equivalent safety and immunogenicity profiles. A phase 1, randomized, double-blind, single-dose, parallel-group, three-arm study also compared the pharmacokinetic profile of the biosimilar to ustekinumab in 294 healthy adults.

Ustekinumab-aekn is expected to be marketed in the United States on or after February 21, 2025 per a settlement and license agreement with Johnson & Johnson. 

A version of this article appeared on Medscape.com.

Gut microbiota signatures associated with KRAS mutations in patients with colorectal cancer (CRC) have been identified by researchers.

Their findings suggest that the gut microbes may serve as noninvasive biomarkers to help identify subtypes of CRC and guide personalized treatment recommendations.

“Our new work contributes to the growing body of evidence highlighting the significance of microbiota-driven mechanisms in cancer pathogenesis,” lead investigator Weizhong Tang, MD, with Guangxi Medical University Cancer Hospital in Nanning, China, said in a statement. 

The research was recently published online in Microbiology Spectrum. 

The onset and growth of CRC has been linked both to imbalances in the gut microbiome and to mutations in the KRAS gene — about 40% of people with CRC have a KRAS mutation. Yet, the interplay between gut dysbiosis and KRAS mutations in CRC remains unclear. 

To investigate further, Dr. Tang and colleagues used 16s rRNA sequencing to analyze stool samples from 94 patients with CRC, including 24 with KRAS-mutated CRC and 70 with KRAS wild-type (nonmutated) CRC. 

The researchers identified 26 distinct types of gut microbiota with statistically significant differences in abundance between the KRAS mutant and KRAS wild-type CRC patients.

At the genus level, Fusobacterium, Clostridium, and Shewanella were all abundant in the KRAS mutant group. 

Fusobacterium is a Gram-negative microbe found in the gastrointestinal tract and the oral cavity. Recent studies have established a strong link between Fusobacterium and CRC development. Other work found elevated levels of Fusobacterium nucleatum were not only closely associated with KRAS mutation but also correlated with chemoresistance in CRC.

Clostridium produces metabolites in the large intestine, which are known to cause DNA damage and trigger inflammatory responses, thereby increasing the risk of CRC development. 

Similarly, Shewanella has been proven to be a contributor to CRC development.

The researchers say it’s “plausible” to consider all three as potential noninvasive biomarkers for identifying KRAS mutation in CRC patients.

In contrast, Bifidobacterium and Akkermansia were abundant in the KRAS wild-type group. 

Bifidobacterium is a probiotic with antitumor activity and Akkermansia is a Gram-negative anaerobic bacterium abundant in the gut and currently recognized as a potential probiotic. 

The researchers speculated that CRC patients may have a reduced likelihood of developing KRAS mutation in the presence of Bifidobacterium and Akkermansia.

Analyses of biological pathways of gut microbiota associated with KRAS mutation status in CRC revealed a significantly higher abundance of the isoflavonoid biosynthesis pathway in the KRAS wild-type group compared with the KRAS mutant group.

“In comparison to KRAS mutant CRC, it is postulated that KRAS wild-type CRC may be less aggressive due to the upregulation of the isoflavonoid biosynthesis pathway, which may inhibit CRC development and progression,” the authors wrote.

Promising Predictive Model

Dr. Tang and colleagues also developed a machine learning model to predict KRAS mutation status in CRC patients based on the gut microbiota signature in KRAS mutant CRC. 

The initial results underscore the model’s predictive efficacy and suggest that it has “considerable potential for clinical application, offering a novel dimension in the prediction of KRAS mutation status among CRC patients in a clinical setting,” the authors wrote. 

They caution that the model requires data from a larger cohort to improve its efficacy, and they plan to do larger studies to validate the findings. 

The study had no commercial funding. The authors declared no relevant conflicts of interest. 

A version of this article appeared on Medscape.com.

Gut microbiota signatures associated with KRAS mutations in patients with colorectal cancer (CRC) have been identified by researchers.

Their findings suggest that the gut microbes may serve as noninvasive biomarkers to help identify subtypes of CRC and guide personalized treatment recommendations.

“Our new work contributes to the growing body of evidence highlighting the significance of microbiota-driven mechanisms in cancer pathogenesis,” lead investigator Weizhong Tang, MD, with Guangxi Medical University Cancer Hospital in Nanning, China, said in a statement. 

The research was recently published online in Microbiology Spectrum. 

The onset and growth of CRC has been linked both to imbalances in the gut microbiome and to mutations in the KRAS gene — about 40% of people with CRC have a KRAS mutation. Yet, the interplay between gut dysbiosis and KRAS mutations in CRC remains unclear. 

To investigate further, Dr. Tang and colleagues used 16s rRNA sequencing to analyze stool samples from 94 patients with CRC, including 24 with KRAS-mutated CRC and 70 with KRAS wild-type (nonmutated) CRC. 

The researchers identified 26 distinct types of gut microbiota with statistically significant differences in abundance between the KRAS mutant and KRAS wild-type CRC patients.

At the genus level, Fusobacterium, Clostridium, and Shewanella were all abundant in the KRAS mutant group. 

Fusobacterium is a Gram-negative microbe found in the gastrointestinal tract and the oral cavity. Recent studies have established a strong link between Fusobacterium and CRC development. Other work found elevated levels of Fusobacterium nucleatum were not only closely associated with KRAS mutation but also correlated with chemoresistance in CRC.

Clostridium produces metabolites in the large intestine, which are known to cause DNA damage and trigger inflammatory responses, thereby increasing the risk of CRC development. 

Similarly, Shewanella has been proven to be a contributor to CRC development.

The researchers say it’s “plausible” to consider all three as potential noninvasive biomarkers for identifying KRAS mutation in CRC patients.

In contrast, Bifidobacterium and Akkermansia were abundant in the KRAS wild-type group. 

Bifidobacterium is a probiotic with antitumor activity and Akkermansia is a Gram-negative anaerobic bacterium abundant in the gut and currently recognized as a potential probiotic. 

The researchers speculated that CRC patients may have a reduced likelihood of developing KRAS mutation in the presence of Bifidobacterium and Akkermansia.

Analyses of biological pathways of gut microbiota associated with KRAS mutation status in CRC revealed a significantly higher abundance of the isoflavonoid biosynthesis pathway in the KRAS wild-type group compared with the KRAS mutant group.

“In comparison to KRAS mutant CRC, it is postulated that KRAS wild-type CRC may be less aggressive due to the upregulation of the isoflavonoid biosynthesis pathway, which may inhibit CRC development and progression,” the authors wrote.

Promising Predictive Model

Dr. Tang and colleagues also developed a machine learning model to predict KRAS mutation status in CRC patients based on the gut microbiota signature in KRAS mutant CRC. 

The initial results underscore the model’s predictive efficacy and suggest that it has “considerable potential for clinical application, offering a novel dimension in the prediction of KRAS mutation status among CRC patients in a clinical setting,” the authors wrote. 

They caution that the model requires data from a larger cohort to improve its efficacy, and they plan to do larger studies to validate the findings. 

The study had no commercial funding. The authors declared no relevant conflicts of interest. 

A version of this article appeared on Medscape.com.

Gut microbiota signatures associated with KRAS mutations in patients with colorectal cancer (CRC) have been identified by researchers.

Their findings suggest that the gut microbes may serve as noninvasive biomarkers to help identify subtypes of CRC and guide personalized treatment recommendations.

“Our new work contributes to the growing body of evidence highlighting the significance of microbiota-driven mechanisms in cancer pathogenesis,” lead investigator Weizhong Tang, MD, with Guangxi Medical University Cancer Hospital in Nanning, China, said in a statement. 

The research was recently published online in Microbiology Spectrum. 

The onset and growth of CRC has been linked both to imbalances in the gut microbiome and to mutations in the KRAS gene — about 40% of people with CRC have a KRAS mutation. Yet, the interplay between gut dysbiosis and KRAS mutations in CRC remains unclear. 

To investigate further, Dr. Tang and colleagues used 16s rRNA sequencing to analyze stool samples from 94 patients with CRC, including 24 with KRAS-mutated CRC and 70 with KRAS wild-type (nonmutated) CRC. 

The researchers identified 26 distinct types of gut microbiota with statistically significant differences in abundance between the KRAS mutant and KRAS wild-type CRC patients.

At the genus level, Fusobacterium, Clostridium, and Shewanella were all abundant in the KRAS mutant group. 

Fusobacterium is a Gram-negative microbe found in the gastrointestinal tract and the oral cavity. Recent studies have established a strong link between Fusobacterium and CRC development. Other work found elevated levels of Fusobacterium nucleatum were not only closely associated with KRAS mutation but also correlated with chemoresistance in CRC.

Clostridium produces metabolites in the large intestine, which are known to cause DNA damage and trigger inflammatory responses, thereby increasing the risk of CRC development. 

Similarly, Shewanella has been proven to be a contributor to CRC development.

The researchers say it’s “plausible” to consider all three as potential noninvasive biomarkers for identifying KRAS mutation in CRC patients.

In contrast, Bifidobacterium and Akkermansia were abundant in the KRAS wild-type group. 

Bifidobacterium is a probiotic with antitumor activity and Akkermansia is a Gram-negative anaerobic bacterium abundant in the gut and currently recognized as a potential probiotic. 

The researchers speculated that CRC patients may have a reduced likelihood of developing KRAS mutation in the presence of Bifidobacterium and Akkermansia.

Analyses of biological pathways of gut microbiota associated with KRAS mutation status in CRC revealed a significantly higher abundance of the isoflavonoid biosynthesis pathway in the KRAS wild-type group compared with the KRAS mutant group.

“In comparison to KRAS mutant CRC, it is postulated that KRAS wild-type CRC may be less aggressive due to the upregulation of the isoflavonoid biosynthesis pathway, which may inhibit CRC development and progression,” the authors wrote.

Promising Predictive Model

Dr. Tang and colleagues also developed a machine learning model to predict KRAS mutation status in CRC patients based on the gut microbiota signature in KRAS mutant CRC. 

The initial results underscore the model’s predictive efficacy and suggest that it has “considerable potential for clinical application, offering a novel dimension in the prediction of KRAS mutation status among CRC patients in a clinical setting,” the authors wrote. 

They caution that the model requires data from a larger cohort to improve its efficacy, and they plan to do larger studies to validate the findings. 

The study had no commercial funding. The authors declared no relevant conflicts of interest. 

A version of this article appeared on Medscape.com.

TOPLINE:

Biscuits reformulated with the sweeteners and sweetness enhancers (S&SEs) neotame and stevia rebaudioside M (StRebM) yield appetite responses similar to those of sucrose-sweetened ones but decrease post-meal insulin and glucose levels in adults with overweight or obesity.

METHODOLOGY:

• In 2023, the World Health Organization issued a conditional recommendation that S&SE should not be used for weight control, apparently due to a lack of evidence for a clear benefit and weak evidence linking S&SE intake with excess weight and poorer health outcomes.
• This randomized crossover trial, conducted in England and France between 2021 and 2022, evaluated the acute (1 day) and repeated (daily for 2 weeks) effects of S&SEs vs sucrose in solid food on appetite and endocrine responses in adults with overweight or obesity.
• Overall, 53 adults (33 women, 20 men; aged 18-60 years) with overweight or obesity consumed biscuits with fruit filling containing either sucrose or reformulated with the S&SEs StRebM or neotame, daily for three 2-week intervention periods separated by a washout period of 14-21 days.
• Participants were required to fast for 12 hours before attending a laboratory session at the beginning (day 1) and end (day 14) of each consumption period.
• The primary endpoint was the composite appetite score, while secondary endpoints included food preferences, postprandial glucose and insulin response, and other satiety-related peptides, such as ghrelin, glucagon-like peptide 1, and pancreatic polypeptide.

TAKEAWAY:

• The composite appetite scores were comparable between the sucrose, StRebM, and neotame groups, with lower appetite suppression observed on day 14 than on day 1 for all three formulations.
• Neotame (P < .001) and StRebM (P < .001) lowered postprandial insulin levels compared with sucrose, while glucose levels saw a decline only with StRebM (and not with neotame) compared with sucrose (P < .05).
• The S&SEs had no effect on satiety levels, as any acute or repeated exposures to StRebM or neotame vs sucrose did not affect the ghrelin and glucagon-like peptide-1 responses.
• Gastrointestinal issues were more frequently reported in the neotame and StRebM groups than in the sucrose group.

IN PRACTICE:

“There is no detrimental impact of replacing sugar with S&SE in these endpoints,” the authors wrote. “Additionally, glucose and insulin responses were blunted after acute and repeated consumption of S&SE-reformulated biscuits, which may confer a benefit for blood glucose control, for example, in individuals at risk of developing type 2 diabetes.”

SOURCE:

This study was led by Catherine Gibbons, School of Psychology, Faculty of Medicine and Health, University of Leeds, England. It was published online in eBioMedicine.

LIMITATIONS:

The reformulated products required the addition of polyol bulking agents (8% maltitol and 8% sorbitol) to match the biscuits in sensory qualities as closely as possible. Gastrointestinal symptoms (initial bloating and flatulence) in the neotame and StRebM formulations may be due to the polyols, classed as low-digestible carbohydrates.

DISCLOSURES:

This study received funding from a European Union Horizon 2020 program, SWEET (Sweeteners and sweetness enhancers: Impact on health, obesity, safety, and sustainability). The authors reported receiving funding and honoraria from the food and beverage industry and trade groups from various entities.

A version of this article appeared on Medscape.com.

TOPLINE:

Biscuits reformulated with the sweeteners and sweetness enhancers (S&SEs) neotame and stevia rebaudioside M (StRebM) yield appetite responses similar to those of sucrose-sweetened ones but decrease post-meal insulin and glucose levels in adults with overweight or obesity.

METHODOLOGY:

• In 2023, the World Health Organization issued a conditional recommendation that S&SE should not be used for weight control, apparently due to a lack of evidence for a clear benefit and weak evidence linking S&SE intake with excess weight and poorer health outcomes.
• This randomized crossover trial, conducted in England and France between 2021 and 2022, evaluated the acute (1 day) and repeated (daily for 2 weeks) effects of S&SEs vs sucrose in solid food on appetite and endocrine responses in adults with overweight or obesity.
• Overall, 53 adults (33 women, 20 men; aged 18-60 years) with overweight or obesity consumed biscuits with fruit filling containing either sucrose or reformulated with the S&SEs StRebM or neotame, daily for three 2-week intervention periods separated by a washout period of 14-21 days.
• Participants were required to fast for 12 hours before attending a laboratory session at the beginning (day 1) and end (day 14) of each consumption period.
• The primary endpoint was the composite appetite score, while secondary endpoints included food preferences, postprandial glucose and insulin response, and other satiety-related peptides, such as ghrelin, glucagon-like peptide 1, and pancreatic polypeptide.

TAKEAWAY:

• The composite appetite scores were comparable between the sucrose, StRebM, and neotame groups, with lower appetite suppression observed on day 14 than on day 1 for all three formulations.
• Neotame (P < .001) and StRebM (P < .001) lowered postprandial insulin levels compared with sucrose, while glucose levels saw a decline only with StRebM (and not with neotame) compared with sucrose (P < .05).
• The S&SEs had no effect on satiety levels, as any acute or repeated exposures to StRebM or neotame vs sucrose did not affect the ghrelin and glucagon-like peptide-1 responses.
• Gastrointestinal issues were more frequently reported in the neotame and StRebM groups than in the sucrose group.

IN PRACTICE:

“There is no detrimental impact of replacing sugar with S&SE in these endpoints,” the authors wrote. “Additionally, glucose and insulin responses were blunted after acute and repeated consumption of S&SE-reformulated biscuits, which may confer a benefit for blood glucose control, for example, in individuals at risk of developing type 2 diabetes.”

SOURCE:

This study was led by Catherine Gibbons, School of Psychology, Faculty of Medicine and Health, University of Leeds, England. It was published online in eBioMedicine.

LIMITATIONS:

The reformulated products required the addition of polyol bulking agents (8% maltitol and 8% sorbitol) to match the biscuits in sensory qualities as closely as possible. Gastrointestinal symptoms (initial bloating and flatulence) in the neotame and StRebM formulations may be due to the polyols, classed as low-digestible carbohydrates.

DISCLOSURES:

This study received funding from a European Union Horizon 2020 program, SWEET (Sweeteners and sweetness enhancers: Impact on health, obesity, safety, and sustainability). The authors reported receiving funding and honoraria from the food and beverage industry and trade groups from various entities.

A version of this article appeared on Medscape.com.

TOPLINE:

Biscuits reformulated with the sweeteners and sweetness enhancers (S&SEs) neotame and stevia rebaudioside M (StRebM) yield appetite responses similar to those of sucrose-sweetened ones but decrease post-meal insulin and glucose levels in adults with overweight or obesity.

METHODOLOGY:

• In 2023, the World Health Organization issued a conditional recommendation that S&SE should not be used for weight control, apparently due to a lack of evidence for a clear benefit and weak evidence linking S&SE intake with excess weight and poorer health outcomes.
• This randomized crossover trial, conducted in England and France between 2021 and 2022, evaluated the acute (1 day) and repeated (daily for 2 weeks) effects of S&SEs vs sucrose in solid food on appetite and endocrine responses in adults with overweight or obesity.
• Overall, 53 adults (33 women, 20 men; aged 18-60 years) with overweight or obesity consumed biscuits with fruit filling containing either sucrose or reformulated with the S&SEs StRebM or neotame, daily for three 2-week intervention periods separated by a washout period of 14-21 days.
• Participants were required to fast for 12 hours before attending a laboratory session at the beginning (day 1) and end (day 14) of each consumption period.
• The primary endpoint was the composite appetite score, while secondary endpoints included food preferences, postprandial glucose and insulin response, and other satiety-related peptides, such as ghrelin, glucagon-like peptide 1, and pancreatic polypeptide.

TAKEAWAY:

• The composite appetite scores were comparable between the sucrose, StRebM, and neotame groups, with lower appetite suppression observed on day 14 than on day 1 for all three formulations.
• Neotame (P < .001) and StRebM (P < .001) lowered postprandial insulin levels compared with sucrose, while glucose levels saw a decline only with StRebM (and not with neotame) compared with sucrose (P < .05).
• The S&SEs had no effect on satiety levels, as any acute or repeated exposures to StRebM or neotame vs sucrose did not affect the ghrelin and glucagon-like peptide-1 responses.
• Gastrointestinal issues were more frequently reported in the neotame and StRebM groups than in the sucrose group.

IN PRACTICE:

“There is no detrimental impact of replacing sugar with S&SE in these endpoints,” the authors wrote. “Additionally, glucose and insulin responses were blunted after acute and repeated consumption of S&SE-reformulated biscuits, which may confer a benefit for blood glucose control, for example, in individuals at risk of developing type 2 diabetes.”

SOURCE:

This study was led by Catherine Gibbons, School of Psychology, Faculty of Medicine and Health, University of Leeds, England. It was published online in eBioMedicine.

LIMITATIONS:

The reformulated products required the addition of polyol bulking agents (8% maltitol and 8% sorbitol) to match the biscuits in sensory qualities as closely as possible. Gastrointestinal symptoms (initial bloating and flatulence) in the neotame and StRebM formulations may be due to the polyols, classed as low-digestible carbohydrates.

DISCLOSURES:

This study received funding from a European Union Horizon 2020 program, SWEET (Sweeteners and sweetness enhancers: Impact on health, obesity, safety, and sustainability). The authors reported receiving funding and honoraria from the food and beverage industry and trade groups from various entities.

A version of this article appeared on Medscape.com.