Our Verdict
The only probiotic the AGA actively recommends for a specific use case: preventing C. difficile and antibiotic-associated diarrhea in adults on antibiotics. Contains Saccharomyces boulardii CNCM I-745, a yeast (not a bacterium) which means it survives stomach acid and isn't killed by antibiotics. 27+ RCTs and 84% efficacy in antibiotic-associated diarrhea prevention per meta-analysis. Narrow use case, but strong evidence within it.
Evident Ratings
Florastor Florastor Daily Probiotic
Scored across 5 dimensions on a 5-point scale
About Florastor
S. boulardii CNCM I-745 has some of the cleanest research in the category. Szajewska et al.'s 2015 meta-analysis showed a 53% relative reduction in antibiotic-associated diarrhea across 21 RCTs and 4,780 participants. The AGA's 2020 guidelines specifically name it as an option for C. difficile prevention in adults on antibiotics — one of the only brand-identifiable mentions in the entire guideline.
See how Florastor stacks up against every probiotics we tested
Our full probiotics comparison ranks every brand across the same scoring dimensions you saw above — formulation, testing, trust, value, and sourcing.
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