A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome

Background: We aimed to evaluate clinical symptoms in subjects with irritable bowel syndrome receiving Saccharomyces cerevisiae in a randomized double-blind placebo-controlled clinical trial. Methods: Overall, 179 adults with irritable bowel syndrome (Rome III criteria) were randomized to receive once daily 500 mg of Saccharomyces cerevisiae, delivered by one capsule (n=86, F: 84%, age: 42.5 +/- 12.5), or placebo (n=93, F: 88%, age: 45.4 +/- 14) for 8 weeks followed by a 3-week washout period. After a 2-week run-in period, cardinal symptoms (abdominal pain/discomfort, bloating/distension, bowel movement difficulty) and changes in stool frequency and consistency were recorded daily and assessed each week. A safety assessment was carried out throughout the study. Results: The proportion of responders, defined by an improvement of abdominal pain/discomfort, was significantly higher (p=0.04) in the treated group than the placebo group (63% vs 47%, OR=1.88, 95%, CI: 0.99-3.57) in the last 4 weeks of treatment. A non-significant trend of improvement was observed with Saccharomyces cerevisiae for the other symptoms. Saccharomyces cerevisiae was well tolerated and did not affect stool frequency and consistency. Conclusion: Saccharomyces cerevisiae is well tolerated and reduces abdominal pain/discomfort scores without stool modification. Thus, Saccharomyces cerevisiae may be a new promising candidate for improving abdominal pain in subjects with irritable bowel syndrome. (C) 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.