Prevention of beta-lactam-associated diarrhea by Saccharomyces boulardii compared with placebo.

OBJECTIVES: To determine the safety and efficacy of a new preventive agent for antibiotic-associated diarrhea (AAD) in patients receiving at least one beta-lactam antibiotic. METHODS: A double-blinded, placebo-controlled, parallel group study was performed in a high-risk group of hospitalized patients receiving a new prescription for a beta-lactam antibiotic and having no acute diarrhea on enrollment. Lyophilized Saccharomyces boulardii or placebo (1 g/day) was given within 72 h of the start of the antibiotic(s) and continued until 3 days after the antibiotic was discontinued, after which the patients were followed for 7 wk. RESULTS: Of the 193 eligible patients, significantly fewer, 7/97 (7.2%), patients receiving S. boulardii developed AAD compared with 14/96 (14.6%) on placebo (p = 0.02). The efficacy of S. boulardii for the prevention of AAD was 51%. Using a multivariate model to adjust for two independent risk factors for AAD (age and days of cephalosporin use), the adjusted relative risk was significantly protective for S. boulardii (RR = 0.29, 95% CI = 0.08, 0.98). CONCLUSION: The prophylactic use of S. boulardii given with a beta-lactam antibiotic resulted in a significant reduction of AAD with no serious adverse reactions.