Across 10 studies, 8 reported beneficial effects of Saccharomyces boulardii on reducing diarrhea rates, with 2 showing neutral findings and none harmful. Effect sizes ranged from small to large, with a moderate effect size most common. The evidence primarily comes from children with acute gastroenteritis or Helicobacter pylori infection, with a median study duration of 60 days reported in one study. Most studies did not specify a consistent dose, though doses of 250 mg to 500 mg/day appeared frequently.
Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Two neutral RCTs (in pelvic radiotherapy patients and hospitalized patients) suggest the effect may not be universal. Most studies did not report duration or form, limiting dose-form inferences.
abdominal distention (RR = 0.39, 95% CI: 0.26-0.59)
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on Helicobaconstipation (RR = 0.32, 95% CI: 0.18-0.55)
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on HelicobaSpecifically, it reduced the incidence of some gastrointestinal adverse effects and nonspecific adverse effects, including diarrhea (RR = 0.28, 95% CI: 0.22-0.36)
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on Helicobathe treatment group experienced a significantly higher incidence of diarrhea at week 4 compared to the control group (p=0.03)
from: Impact of Saccharomyces boulardii on acute gastrointestinal toxicities in patients undergonausea (RR = 0.59, 95% CI: 0.36-0.97)
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on Helicobarash (RR = 0.49, 95% CI: 0.28-0.86)
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on Helicobano significant differences were found between the groups in terms of ... anti-diarrheal medication use
from: Impact of Saccharomyces boulardii on acute gastrointestinal toxicities in patients undergoOverall, no significant differences were found between the groups in terms of cumulative GI toxicities
from: Impact of Saccharomyces boulardii on acute gastrointestinal toxicities in patients undergoNone of the trials evaluated the effect of S boulardii on stool volume.
from: Systematic review with meta-analysis: Saccharomyces boulardii for treating acute gastroentThere were no adverse drug reactions in both groups.
from: Effectiveness and Safety of Saccharomyces Boulardii for the Treatment of Acute Gastroenterthis review and meta-analysis show that S. boulardii is safe
from: Efficacy and Safety of Saccharomyces boulardii for Acute DiarrheaThe drug was well accepted and tolerated. There were no reports of the side effects during treatment period.
from: Role of a probiotic (Saccharomyces boulardii) in management and prevention of diarrhoea.S. boulardii supplementation to bismuth quadruple therapy significantly improved H. pylori eradication rates (RR = 1.08, 95% CI: 1.04-1.12) and reduced the incidence of total adverse effects (RR = 0.53, 95% CI: 0.45-0.62).
from: Effect of Saccharomyces boulardii supplementation to bismuth quadruple therapy on HelicobaThere were no discernable adverse effects of yeast administration.
from: Prevention of antibiotic-associated diarrhea by Saccharomyces boulardii: a prospective stuAdverse effects were epigastric burning and constipation in M (53%) and M+SB (36%), and flatulence/diarrhea in SB (22%).
from: Effectiveness of Saccharomyces boulardii and Metronidazole for Small Intestinal BacterialS boulardii reduced the risk of diarrhoea on day 2 to day 7 (low quality of evidence).
diarrhea (n = 13 RCTs, 14.7% vs. 32.4%, RR = 0.46, 95% CI: 0.37-0.56, P < 0.00001)
Overall, no significant differences were found between the groups in terms of ... anti-diarrheal medication use
In the following two months, S. boulardii group had a significantly lower frequency of 0.54 episodes as compared to 1.08 episodes in control group.
Of C. difficile-positive patients, 31% (5/16) on placebo developed diarrhea compared with 9.4% (3/32) on S. boulardii; this difference was not statistically significant (p = 0.07).
day 4 (RR, 0.38; 95% CI, 0.24 to 0.59) after intervention compared with control
diarrhea (RR = 0.28, 95% CI: 0.22-0.36)
treatment with Saccharomyces boulardii reduced the average number of diarrhea after 3 days of treatment by about 1.03 (MD = -1.03, 95% CI: -1.53, -0.53)
The mean duration of diarrhoea was 6.16 days (range 2-13 days) in the placebo group and 4.70 days (range 2-10 days) in the S. boulardii group (p<0.05).
The SB and M + SB groups had decreased diarrhea, abdominal pain, and gas/bloating/flatulence, but M remained unchanged.