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

ABSTRACT Background & Aims The aim of this study was to investigate the effectiveness of oral treatment with a non-viable 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, multi-center (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 either to placebo or BL after a two week baseline period. The primary outcome was based on the European Medical 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 drop-out rates. Overall, the response was similar between BL and placebo for IBS-GAI (17.4% and 14.4%, resp., p=·4787) and abdominal pain (42.0% and 35.4%, resp.; p=·1419). Some secondary outcome measures and sensitivity analyses pointed towards potentially higher sensitivity of the abdominal pain measures in IBS-D, but not the other subtypes. For the GAI, no subgroup differences were detected. For diarrhea-predominant IBS (IBS-D), post-hoc analyses for abdominal pain response over time and stool consistency showed potentially promising effects of BL. Finally, the treatment with bacterial lysate was well tolerated. Conclusions BL is not effective across all IBS subtypes. However, BL may offer a treatment option for IBS-D which needs verification by an adequately powered drug-trial; EudraCT-No.: 2012-002741-38.