Heat-Inactivated Treatment Effective for Irritable Bowel Syndrome

Non-viable strains of Bifidobacterium bifidum MIMBb75 (SYN-HI-001) could have advantages over viable bacteria for product stability and standardization, along with for tolerability due to safety concerns raised for specific patient groups with irritable bowel syndrome (IBS) who are susceptible to infections.

A team, led by Viola Andersen, MD, Department of Internal Medicine, Israelitic Hospital, University of Hamburg Teaching Hospital, assessed the efficacy of non-viable, heat-inactivated B bifidum MIMBb75 for the treatment of irritable bowel syndrome and its symptoms.

In the double-blind, placebo-controlled trial, 443 patients with IBS were recruited from 20 sites in Germany. Each patient was randomly assigned to receive either 2 placebo capsules or 2 capsules with a combined total 1 × 10⁹ non-viable B bifidum HI-MIMBb75 cells taken orally once a day for 8 weeks.

Each patient was screened between April 2016 and February 2017.

Eligible patients were diagnosed with IBS based on the Rome III criteria and had abdominal pain (≥4 on an 11-point numerical rating scale) on at least 2 days during a 2-week run-in phase.

The investigators excluded various individuals from the study, including patients with chronic inflammatory bowel diseases, systemic diseases, cancer, autoimmune diseases, with an intake of antipsychotic medications 3 months before study start, or with an intake of systemic corticosteroids within 1 month prior to beginning the trial.

The investigators sought a primary endpoint of the combination of at least a 30% improvement in abdominal pain, coupled with the adequate relief of overall IBS symptoms being fulfilled in at least 4 of the 8 week trial period.

The analysis of the primary endpoint included all randomly assigned patients receiving at least 1 dose of medication who had no severe protocol violation. The safety analysis included patients who had taken at least 1 dose of the treatment, based on the frequency and severity of adverse events, laboratory evaluation, and global assessment of tolerability.

The composite primary endpoint was reached by 74 (34%) of 221 patients in the treatment group. On the other hand, only 43 (19%) of 222 patients in the placebo group met the primary endpoint (RR, 1.7; 95% CI, 1.3—2.4; P = 0.0007).

There were no serious adverse events found in patients in the B bifidum HI-MIMBb75 group, while there were 8 serious adverse events found in the placebo group. There were no deaths reported in either group.

The most common adverse event reported in the study with a suspected relationship to treatment was abdominal pain, which was found in 2 (<1%) patients in the B bifidum HI-MIMBb75 group and 1 (<1%) in the placebo group.

Overall, tolerability was rated as either very good or good by 200 (91%) participants in the treatment group and 191 (86%) individuals in the placebo group.

“This study shows that B bifidum HI-MIMBb75 substantially alleviates IBS and its symptoms in a real-life setting,” the authors wrote. “These results indicate that specific beneficial bacterial effects are mediated independently of cell viability.”

The study, “Heat-inactivated Bifidobacterium bifidum MIMBb75 (SYN-HI-001) in the treatment of irritable bowel syndrome: a multicentre, randomised, double-blind, placebo-controlled clinical trial,” was published online in The Lancet Gastroenterology & Hepatology.