Saccharomyces boulardii as an Adjunct to Helicobacter pylori Eradication Therapy: A Systematic Review and Meta-Analysis.

OBJECTIVE: To systematically evaluate the efficacy, safety, and optimal administration parameters (dosage, treatment duration, regimen type, and publication era of the articles) of Saccharomyces boulardii as an adjunct therapy to Helicobacter pylori eradication therapy. METHODS: We searched PubMed, Web of Science, and EMBASE databases for randomized controlled trials (RCTs) comparing S. boulardii and placebo in addition to H. pylori eradication that were published up to January 2026. Pooled risk ratio (RR) and the corresponding 95% confidence interval (CI), absolute risk differences (ARD), and numbers needed to treat (NNT) were calculated. Certainty of evidence was assessed using GRADE. RESULTS: Nineteen RCTs were included for analysis. Adjuvant S. boulardii significantly improved H. pylori eradication in adults (n = 15; RR 1.07, 95% CI 1.03-1.10; ARD +5.7%; NNT 18) and children (n = 3; RR 1.12, 95% CI 1.03-1.23; ARD +9.8%; NNT 10). Eradication gain was significant with triple therapy (n = 12; RR 1.08, 95% CI 1.03-1.14). Eradication efficacy was consistent across different dosages, treatment durations, and publication eras (p > 0.05 for subgroup interactions). Furthermore, S. boulardii significantly halved overall adverse events (n = 11; 19.7% vs. 36.0%; RR 0.51, 95% CI 0.39-0.66; NNT 6). GRADE certainty was moderate for eradication and low for adverse events. CONCLUSIONS: S. boulardii modestly improves H. pylori eradication-particularly with triple therapy-and substantially mitigates gastrointestinal adverse events. Concurrent dosing of 5 × 109-1 × 1010 CFU/day for 10-14 days appears to be a reasonable and pragmatic regimen. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD420251271815.