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Compound

Saccharomyces Boulardii

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Saccharomyces Boulardii. Beneficial yeast used to prevent and treat several types of diarrhea.

How it works. Yeast competes with pathogens, secretes proteases inactivating C. diff toxins.

What the research supports. 1 graded claims. Strongest: Reduces antibiotic-associated diarrhea & C. diff (strong).

How much to take. Typical dose: 250–500 mg × 2/d (5 billion CFU).

Side effects and interactions. 1 medication interaction listed. Serious: Fungemia in immunocompromised / central line.

Stacking. Pairs well with Vitamin D3 + K2, Zinc. Avoid combining with Immunocompromised state, Central line in place.

Common forms. Available as Lyophilized S. boulardii.

Key studies. 8 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Saccharomyces Boulardii. Anecdotes are not medical advice.

Saccharomyces Boulardii. Beneficial yeast used to prevent and treat several types of diarrhea.

No single structure

What it is

Beneficial yeast used to prevent and treat several types of diarrhea.

Food sources

Lychee fruit (originally)

Goals

Gut HealthImmune Function

How it works

Yeast competes with pathogens, secretes proteases inactivating C. diff toxins.

Pathways

  • Pathogen competition
  • Toxin neutralization

Effects

  • ↓C. difficile recurrence decreases
  • ↓Traveler's diarrhea decreases

What the research supports

Reduces antibiotic-associated diarrhea & C. diffstrong

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
250–500 mg × 2/d (5 billion CFU)
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodWith a meal containing fat for fat-soluble compounds; otherwise either.
Best formMost evidence is based on the lyophilized s. boulardii form.
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Side effects & interactions

Common side effects

  • Bloating

Serious

  • Fungemia in immunocompromised / central line

Medication interactions

Antifungalsmoderate

Antagonistic.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Vitamin D3 + K2Foundational immune modulation.
  • ZincRequired cofactor for innate and adaptive immune function.

Avoid combining

  • Immunocompromised stateFungemia risk.
  • Central line in placeBloodstream invasion.

Common forms

  • Lyophilized S. boulardii

Key studies

8 studies cited in total.

Saccharomyces boulardii for antibiotic-associated diarrhea ↗
Meta-analysis · World J Gastroenterol · 2010

Effective in prevention of AAD and recurrent C. difficile.

PubMed: Saccharomyces Boulardii — Reduces antibiotic-associated diarrhea & C. diff ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Saccharomyces Boulardii and "Reduces antibiotic-associated diarrhea & C. diff". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Saccharomyces Boulardii — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Saccharomyces Boulardii and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

Discussion

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