Rankings / Immune & Inflammation

Saccharomyces boulardii

Immune & Inflammation · Probiotic yeast

Tier A

Reviewed by Read Off Label · Last reviewed · How we grade

microbiomeotc
8 / 10
Tier A
Ev 8 Bn 5 Sf 9

Bottom line

Read Off Label grades Saccharomyces boulardii as A (8.0/10) based on strong evidence, moderate benefit magnitude, and a low-risk safety profile.

Unique advantage of being a yeast — unaffected by concurrent antibiotics.

Typical use: 250-500 mg 2x/day during and 2 weeks after antibiotic course — OTC.

What this is

Unique advantage of being a yeast — unaffected by concurrent antibiotics. One of the most evidence-backed probiotics for specific GI indications. Goldenberg 2017 Cochrane review supports AAD and CDI prevention. Avoid in immunocompromised or patients with indwelling central venous catheters.

Mechanism

Non-pathogenic yeast (actually a strain of S. cerevisiae); intrinsically antibiotic-resistant (unlike bacterial probiotics); binds C. difficile toxins A and B; secretes 54 kDa protease that neutralizes toxin A

Dose & route

250-500 mg 2x/day during and 2 weeks after antibiotic course

Citations

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Common questions

Does Saccharomyces boulardii work?
Read Off Label rates the evidence for Saccharomyces boulardii as Strong and the benefit magnitude as moderate, producing an overall grade of A (8.0/10). Unique advantage of being a yeast — unaffected by concurrent antibiotics.
Is Saccharomyces boulardii safe?
Saccharomyces boulardii has a low risk profile in published human data. Legal status: OTC. This is not medical advice — see the disclaimer.
What is the typical dose for Saccharomyces boulardii?
250-500 mg 2x/day during and 2 weeks after antibiotic course
How does Saccharomyces boulardii work?
Non-pathogenic yeast (actually a strain of S. cerevisiae); intrinsically antibiotic-resistant (unlike bacterial probiotics); binds C. difficile toxins A and B; secretes 54 kDa protease that neutralizes toxin A

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.