Heat-inactivated probiotic effective in irritable bowel syndrome

Last Updated: 2020-04-14

By Marilynn Larkin

NEW YORK (Reuters Health) - Patients with irritable bowel syndrome (IBS) achieved symptom relief with heat-inactivated bifidobacterium bifidum MIMBb75 (SYN-HI-001) in a placebo-controlled trial.

"Bifidobacterium bifidum MIMBb75 is one of a few probiotic strains that have been shown to be effective in the treatment of (IBS) and its symptoms," note Dr. Peter Layer of the University of Hamburg Teaching Hospital in Germany and colleagues. "Non-viable strains might have advantages over viable bacteria for product stability and standardization, as well as for tolerability because safety concerns have been raised for specific patient groups who are susceptible to infection."

In the double-blind trial in IBS patients in Germany, the primary composite endpoint was a combination of at least 30% improvement of abdominal pain and adequate relief of overall IBS symptoms in at least four of eight treatment weeks.

As reported in The Lancet Gastroenterology and Hepatology, 443 patients (mean age, 42; 70% women) were randomized to two capsules with a combined total of 1 10(9) non-viable B bifidum HI-MIMBb75 cells to be taken once daily for eight weeks or two capsules of placebo.

The composite primary endpoint was reached by 34% of the probiotic patients compared with 19% of those taking placebo (risk ratio, 1.7).

A significantly greater proportion of patients in the probiotic group reported adequate symptom relief, defined as a Likert score of 3 or less: 60% versus 44%; RR, 1.4.

Consistently greater symptom relief throughout the study was reported for HI-MIMBb75. At the end of week 1, the mean symptom relief score was 3.62 for the probiotic and 3.78 for placebo; at the end of treatment, the mean symptom relief score decreased to 3.08 in the B bifidum HI-MIMBb75 group compared to 3.44 for placebo.

A composite score of 1-4 was calculated for IBS symptoms: subject's global assessment of symptoms, abdominal pain, distension or bloating, and urgency. The probiotic group showed a significantly greater improvement in the composite score compared with the placebo group (change from baseline to end of treatment of -1.21 points vs. - 0.89 points).

Seven adverse events (none serious) suspected to be related to the study product were reported in the probiotic group, as were eight in the placebo group.

The most commonly reported adverse event with a suspected relationship to the study product was abdominal pain, in two (<1%) patients in the B bifidum HI-MIMBb75 group and one (<1%) in the placebo group.

Global assessment of tolerability at the end of treatment was rated very good or good by 91% of patients in the B bifidum HI-MIMBb75 group and 86% of patients in the placebo group.

No deaths were reported.

Dr. Nicholas Talley of the University of Newcastle in New South Wales, coauthor of a related editorial, told Reuters Health by email, "Bacterial therapy for the treatment of IBS to positively manipulate the intestinal microbiome is of intense interest. It has generally been accepted probiotic efficacy requires live bacteria, but this latest trial suggests an inactivated probiotic is efficacious over placebo."

"However," he said, "while safe, the therapeutic gain of selected probiotics over placebo is modest for IBS, and alternative approaches are needed."

Dr. Bryan Curtin, Director of Neurogastroenterology and Motility at Mercy Medical Center in Baltimore, commented in an email to Reuters Health, "IBS remains very challenging to treat and to have another relatively low-risk option for healthier patients is definitely welcome."

However, he noted, "The exclusion criteria are very strict, basically requiring that patients have no comorbidities and no recent history of psychiatric medications. In general, the most challenging IBS patients are the ones that also have co-existing disease, so while the results of the study are promising, their applicability may be of limited use in the patients that need additional therapies the most."

The study was funded by Synformulas.

Dr. Layer did not respond to requests for a comment.

SOURCE: https://bit.ly/2V74oRF and https://bit.ly/2z1IUgt The Lancet Gastroenterology and Hepatology, online April 8, 2020.