saccharomyces boulardii
What does the research say about saccharomyces boulardii?
9 health outcomes synthesisedResearch on Saccharomyces boulardii spans 9 health outcomes, with the strongest evidence supporting its use for reducing diarrhea — 9 studies show moderate effects in clinical populations such as patients with H. pylori infection, pelvic radiotherapy, or antibiotic use. Effective doses range from 250 mg/day to 500 mg four times daily, though most studies were short-term (14 days).
Strongest evidence
Two outcomes have high evidence strength. For reduced diarrhea, all 9 studies reported beneficial effects with a moderate effect size (doses: 250 mg/day to 500 mg four times daily), primarily in clinical populations (e.g., H. pylori patients, pelvic radiotherapy, critically ill tube-fed patients). For improved H. pylori eradication rates, 5 of 7 studies found a small benefit (risk ratios 1.09–1.14) with a typical dose of 250 mg twice daily; two neutral studies may lack power.
Moderate and mixed evidence
Six outcomes have moderate evidence, all showing predominantly beneficial effects but with caveats. Reduced diarrhea rate (8 of 10 studies beneficial, moderate effect) and increased H. pylori eradication rate (4 of 5 beneficial, small effect) are supported by meta-analyses, though publication bias and inconsistent dosing limit confidence. Reduced abdominal pain (4 of 5 beneficial, mixed effect sizes) and reduced duration of diarrhea (3 of 4 beneficial, small effect) have smaller study bases. Reduced constipation and reduced abdominal distension (each 3 of 3 beneficial, large effect) are promising but based on few studies, all in H. pylori patients. Reduced stool frequency (3 of 3 beneficial, moderate effect) has low evidence due to small sample sizes and limited reporting.
Effective dose patterns
Across outcomes, the most consistently reported effective doses are 250 mg twice daily (for H. pylori-related outcomes and stool frequency) and 250 mg/day to 500 mg up to four times daily (for diarrhea). Many studies did not specify form or duration, but when reported, capsule form and 14-day courses were common.
Population insights
Most evidence comes from clinical populations: patients with H. pylori infection, children with acute gastroenteritis, hospitalized patients on antibiotics, and those undergoing pelvic radiotherapy. Benefits in healthy individuals or for general prevention are not well studied.
Notable caveats
- Publication bias is flagged across nearly all syntheses — null results are less likely to be published.
- Study durations are often short (median 14 days); long-term effects are unknown.
- Doses and supplement forms are inconsistently reported, limiting practical guidance.
- Generalizability to non-clinical populations is uncertain.
Frequently asked
What is Saccharomyces boulardii good for according to research?
The strongest research support is for reducing diarrhea — 9 studies found moderate beneficial effects in clinical populations. Other promising areas include improving Helicobacter pylori eradication rates (5 of 7 studies, small effect) and reducing abdominal distension and constipation (each 3 of 3 studies, large effect). However, evidence strength varies, and most studies are in specific patient groups.What dose of Saccharomyces boulardii is typically used in studies?
The most common reported doses are 250 mg twice daily (for H. pylori and stool frequency outcomes) and 250 mg to 500 mg up to four times daily (for diarrhea). Many studies did not consistently report dose, form, or duration, so these ranges come from the subset that did. Capsule form is mentioned in some diarrhea studies.Who benefits most from Saccharomyces boulardii?
Research primarily shows benefits in clinical populations: patients with H. pylori infection (both children and adults), children with acute gastroenteritis, hospitalized patients on antibiotics, and those undergoing pelvic radiotherapy. Evidence for healthy individuals or general prevention is lacking.Are there caveats or limitations in the research on Saccharomyces boulardii?
Yes, multiple caveats are noted across studies. Publication bias is a concern — null results are less likely to be published. Most studies have short durations (often 14 days), and many do not report supplement form or consistent doses. Generalizability to healthy populations is uncertain.Does Saccharomyces boulardii help with H. pylori eradication?
Evidence suggests a small but consistent benefit. Two high-evidence syntheses show that adding Saccharomyces boulardii to standard therapy improves eradication rates by about 10–14 percentage points (risk ratios 1.09–1.14). Typical dose is 250 mg twice daily for 14 days, though neutral studies exist.Can Saccharomyces boulardii reduce abdominal pain or bloating?
Research indicates potential benefit for abdominal pain (4 of 5 studies beneficial, moderate-to-large effect) and abdominal distension (3 of 3 meta-analyses, large effect). All studies were in H. pylori patients, and doses were often not reported, so applicability to other causes of pain or distension is unclear.
- High evidenceReduced Diarrhea
- High evidenceImproved H Pylori Eradication Rates
- Moderate evidenceReduced Diarrhea Rate
- Moderate evidenceReduced Abdominal Pain
- Moderate evidenceIncreased Helicobacter pylori Eradication Rate
- Moderate evidenceReduced Duration of Diarrhea
- Moderate evidenceReduced Abdominal Distension
- Moderate evidenceReduced Constipation
- Low evidenceReduced Stool Frequency
- Reduced Antibiotic-Associated Diarrhea