Best Supplements for Improved Gut Health
Ranked by research evidence. Compare 38 supplements across 58 papers from the biomedical literature, with effect direction, evidence strength, and dose range for each.
Top picks by evidence
- Low evidence6 studies
Across 6 studies, all reported beneficial effects on gut health for Lactobacillus salivarius UCC118, with effect sizes predominantly small (4 small, 2 moderate). No studies reported statistically significant findings, and the evidence base consists entirely of review articles and one in silico/animal study on a related strain. Dose ranges and populations were not consistently reported.
- Low evidence5 studies
All 5 studies reported beneficial effects for improved gut health, with 3 showing a moderate effect size and 2 showing a small effect. Only 1 study reached statistical significance. Evidence comes exclusively from animal studies (livestock and pets) and reviews; no human trials or consistent dose/duration data were reported.
- Low evidence3 studies
Across 3 review papers, all reported beneficial effects of Lactobacillus fermentum HA-179 on gut health, with effect sizes ranging from small to moderate. One study indicated a moderate-sized benefit, specifically showing an increase in beneficial fecal bacteria (lactobacilli and bifidobacteria) and a reduction in potentially harmful bacteria (clostridia and enterobacteria). No dose, duration, population, or form data were consistently reported, limiting specificity.
- LowLactobacillus salivarius UCC118Across 6 studies, all reported beneficial effects on gut health for Lactobacillus salivarius UCC118, with effect sizes predominantly small (4 small, 2 moderate). No studies reported statistically significant findings, and the evidence base consists entirely of review articles and one in silico/animal study on a related strain. Dose ranges and populations were not consistently reported.6 beneficial6 studies
- LowLactobacillus acidophilus L-92All 5 studies reported beneficial effects for improved gut health, with 3 showing a moderate effect size and 2 showing a small effect. Only 1 study reached statistical significance. Evidence comes exclusively from animal studies (livestock and pets) and reviews; no human trials or consistent dose/duration data were reported.5 beneficial5 studies
- LowLactobacillus fermentum HA-179Across 3 review papers, all reported beneficial effects of Lactobacillus fermentum HA-179 on gut health, with effect sizes ranging from small to moderate. One study indicated a moderate-sized benefit, specifically showing an increase in beneficial fecal bacteria (lactobacilli and bifidobacteria) and a reduction in potentially harmful bacteria (clostridia and enterobacteria). No dose, duration, population, or form data were consistently reported, limiting specificity.3 beneficial3 studies
- Very lowKefir CultureAcross 3 studies, all reported beneficial small-sized effects of kefir culture on gut health. However, no studies reported statistically significant findings, and all three are review or characterization studies rather than controlled trials in humans. The evidence is preliminary and based on indirect or theoretical benefits.3 beneficial3 studies
- Very lowBifidobacterium animalis subsp. lactis BB-12Across 3 studies (all of which are review papers), all reported beneficial effects, with effect sizes ranging from small to moderate (predominantly moderate). The evidence base consists entirely of reviews rather than primary interventional trials, and no dose, duration, form, or population data were reported in the included studies. None of the studies provided statistical significance data, and study durations were not consistently reported.3 beneficial3 studies
- Very lowLactobacillus rhamnosusAcross 3 review studies, all reported beneficial effects of Lactobacillus rhamnosus on gut health, with moderate effect sizes in two studies and a small effect in one. Evidence is derived from animal and aquaculture populations, with no human-specific data. Doses, forms, and study durations were not reported, limiting applicability to human supplementation.3 beneficial3 studies