Interactive tool · Strain lookup
Strain-to-Evidence Lookup
The Probiotic Strain Finder starts from a goal. This tool starts from a strain — one you read on a label, saw in an ad, or heard about — and shows exactly what the human evidence supports for it, with an honest grade, across all 16 strains in our roster.
This is a general educational guide, not medical advice, and not a product recommendation. Probiotic effects are small, strain-specific, and individual — they are not drugs and do not replace diet, exercise, or prescribed treatment. The evidence below belongs to a specific strain at a specific dose, which is rarely the same as a product on a shelf. If you are immunocompromised, critically ill, pregnant, have a central line, or have a serious GI condition, probiotics can carry real risks — talk to a licensed clinician or registered dietitian before starting anything.
- Akkermansia muciniphila (pasteurized, Muc₁₀₀₀₀₀)Modest
Blood sugar / metabolicModest
A small 3-month RCT in overweight/insulin-resistant adults found pasteurized Akkermansia improved insulin sensitivity and some metabolic markers. One short, single trial.
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- Bifidobacterium & Lactobacillus blendsModest
General gut healthModest
Common, well-tolerated, broadly studied for general digestive comfort; benefits are individual and often subtle in people without symptoms.
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- Bifidobacterium lactis B420Modest
Blood sugar / metabolicModest
In a 6-month RCT, B420 modestly reduced body-fat mass versus placebo; metabolic read-throughs were secondary and smaller.
Read the evidence →Weight / body fatModest
The best single-strain body-fat trial here: ~6 months of B420 modestly lowered fat mass and waist size versus placebo.
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- Bifidobacterium lactis DN-173 010Moderate
Constipation / regularityModerate
Studied as a fermented-milk product; improves transit time and stool frequency, especially in women, in several trials.
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- Bifidobacterium lactis HN019Moderate
Constipation / regularityModerate
Multiple RCTs show HN019 shortens whole-gut transit time and improves regularity — among the strongest strain-specific constipation data.
Read the evidence →Bloating / gasModest
Best evidenced for speeding gut transit (constipation-type bloating); shortening transit can reduce the trapped-gas kind of bloat for some.
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- Clostridium butyricum CBM588Thin
Blood sugar / metabolicThin
A butyrate-producing strain with mechanistic and early human data relevant to metabolism; direct metabolic-endpoint RCTs in this context are limited.
Read the evidence →Bloating / gasThin
A butyrate-maker studied mostly for GI-infection and antibiotic-related symptoms; bloating-specific human data is limited.
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- Dietary fiber + fermented foods (first line)Moderate
General gut healthModerate
Increasing fiber and fermented-food variety has the most consistent human evidence for a healthier, more diverse microbiome — stronger than any single supplement strain.
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- Hafnia alvei HA4597Thin
Weight / body fatThin
An “appetite” strain built on a ClpB / α-MSH mimicry mechanism, with one small weight-management RCT. Intriguing but early.
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- Lactobacillus gasseri SBT2055Modest
Weight / body fatModest
A 12-week RCT in adults with an obese tendency reported a small reduction in abdominal (visceral) fat that partly rebounded after stopping.
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- Lactobacillus rhamnosus GGModerate
Post-antibiotic recoveryModerate
One of the most-studied strains for reducing antibiotic-associated diarrhea, particularly in children; effect sizes are real but modest.
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- Multi-strain blends (for GLP-1 GI upset)Thin
Bloating / gasThin
Evidence that a probiotic eases GLP-1-related nausea or bloating is indirect; some people improve, others get more gas. Start low and judge by your own response.
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- Multi-strain blends (meta-analytic)Modest
Blood sugar / metabolicModest
Meta-analyzes of probiotics in type-2 diabetes show a small average drop in fasting glucose and HbA1c, but with high heterogeneity across strains and products.
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- Probiotics in general (meta-analytic)Modest
Weight / body fatModest
Pooled RCTs show a statistically real but tiny average effect on body weight and BMI — on the order of under a kilogram. Don’t expect a visible change.
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- Saccharomyces boulardii (a beneficial yeast)Moderate
Post-antibiotic recoveryModerate
Among the best-evidenced agents for preventing antibiotic-associated diarrhea in meta-analyzes. Note it is a yeast, not a bacterium, so antibiotics don’t kill it.
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- Spore-based (Bacillus) probioticsThin
General gut healthThin
Survive stomach acid well and are heavily marketed for gut health, but the human metabolic/general-health evidence is still early and thin.
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- Whole-diet fiber + fermented foods (not a pill)Modest
Post-antibiotic recoveryModest
Recovery of the broader community after antibiotics is driven mostly by dietary fiber, fermented foods, and time — a single probiotic won’t “reset” it.
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How to read the grades. Moderate = at least one solid randomized trial with a meaningful, replicated-direction result (still modest by drug standards). Modest = one or two small or short trials, or a noisy pooled signal. Thin = mostly mechanistic, animal, or early human data — a hypothesis, not a recommendation. A strain shows its strongest grade across the goals it is evidenced for; the per-goal grade underneath may be lower.
How this is built
Every strain, evidence note, grade, and citation link here is drawn from the same goal-by-goal mapping behind the Probiotic Strain Finder — this tool only re-indexes it by strain name instead of by goal, so a strain evidenced under more than one goal (weight and blood sugar, for example) shows every goal-scoped note rather than being flattened into one. Grades stay deliberately conservative: Moderate means at least one solid randomized trial with a meaningful result (still modest by drug standards), Modest means one or two small trials or noisy pooled data, and Thin means mostly mechanism or early data. Most probiotic claims land at Modest or Thin, and we would rather say so than oversell.
This tool is informational and not medical advice. It summarizes published human evidence at a population level and cannot account for your individual health, medications, immune status, or GI conditions. Probiotics are not a treatment for any disease. Talk to a licensed clinician or registered dietitian before starting, stopping, or changing any supplement.