A Nonviable Probiotic in Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Study

BACKGROUND & AIMS: The aim of this study was to investigate the effectiveness of oral treatment with a nonviable probiotic lysate (BL) of Escherichia coli (DSM 17252) and Enterococcus faecalis (DSM 16440) in patients with irritable bowel syndrome (IBS). METHODS: A phase IV, randomized, double-blind, placebo-controlled, multicenter (30 study sites), parallel group study was conducted in 389 patients of both sexes with IBS according to Rome III criteria. The treatment period was 26 weeks. The participants were allocated to either placebo or BL after a 2-week baseline period. The primary outcome was based on the European Medicines Agency IBS guideline: improvement in global assessment (GAI) and improvement in abdominal pain. RESULTS: Patients (BL, n = 191; placebo, n = 198) had similar baseline values and dropout rates. Overall, the response was similar between BL and placebo for IBS-GAI (17.4% and 14.4%, respectively; P = center dot 4787) and abdominal pain (42.0% and 35.4%, respectively; P = center dot 1419). Some secondary outcome measures and sensitivity analyses pointed toward potentially higher sensitivity of the abdominal pain measures in diarrhea-predominant IBS (IBS-D) but not the other subtypes. For the GAI, no subgroup differences were detected. For IBS-D, post hoc analyses for abdominal pain response over time and stool consistency showed potentially promising effects of BL. Finally, the treatment with BL was well-tolerated. CONCLUSIONS: BL is not effective across all IBS subtypes. However, BL may offer a treatment option for IBS-D that needs verification by an adequately powered drug trial; EudraCT-No.: 2012-002741-38.