Saccharomyces boulardii CNCM I-745 probiotic does not alter the pharmacokinetics of amoxicillin

Probiotics are live microbial organisms that provide benefit to the host while co-habitating in the gastrointestinal tract. Probiotics are safe, available over the counter, and have clinical benefit by reducing the number of antibiotic-associated diarrhea days. Prescriptions from providers and direct consumer demand of probiotics appear to be on the rise. Several recent animal studies have demonstrated that probiotics may have significant effect on absorption of co-administered drugs. However, to date, most probiotic-drug interaction studies in animal models have been limited to bacterial probiotics and nonantibiotic drugs. We performed a traditional pharmacokinetic mouse study examining the interactions between a common commercially available yeast probiotic, Saccharomyces boulardii CNCM I-745 (Florastor^®) and an orally administered amoxicillin. We showed that there were no significant differences in pharmacokinetic parameters (half-life, area under the curve, peak concentrations, time to reach maximum concentration, elimination rate constant) of amoxicillin between the probiotic treated and untreated control groups. Altogether, our findings suggest that coadministration or concurrent use of S. boulardii probiotic and amoxicillin would not likely alter the efficacy of amoxicillin therapy.