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Research on probiotics for weight loss shows small average effects. Pooled analyses of randomized trials found differences of well under 1 kg (about 2 pounds) compared with placebo, usually over 3 to 12 weeks, and the results depend on the specific strain. A Cleveland Clinic gut microbiome researcher put it bluntly: available probiotics probably won’t help people lose much, if any, weight. No probiotic is FDA-approved for weight loss. This guide covers what the studies on probiotics and weight loss found, which strains were tested, and what products sold as a weight loss probiotic actually contain.
Peptide Labs sells probiotic supplements, and we mention three below. This article is general information, not medical advice.
Key Takeaways
- Meta-analyses report average weight differences of about 0.6 to 0.9 kg versus placebo.
- Most trials were short and many were funded by probiotic or dairy companies.
- Effects are strain-specific; a species name on a label does not mean the studied strain.
- Many weight-focused probiotics also contain green tea, berberine or other non-probiotic ingredients.
- Pendulum states its GLP-1 Probiotic is not intended for weight loss.
What studies show about probiotics for weight loss
Two large meta-analyses are cited most often:
| Review | What was pooled | Main result | Limits |
|---|---|---|---|
| Borgeraas et al., 2018 (Obesity Reviews) | 15 trials, 957 adults with overweight or obesity, 3 to 12 weeks | Weight 0.60 kg lower than placebo; BMI 0.27 lower; fat mass not significant | Authors called the effects small |
| Koutnikova et al., 2019 (BMJ Open) | 105 trial reports, 6,826 people | In people with overweight (not obesity) weight 0.94 kg lower; waist 1.3 cm smaller | Two authors worked for Danone; results influenced by trials from one country |
Both reviews found statistically significant but modest differences. Borgeraas and colleagues noted that fat mass did not change significantly. Koutnikova and colleagues described the improvements as minor but consistent, and found them in people with overweight rather than obesity. Neither review shows that any probiotic produces meaningful weight loss on its own.
Why researchers link gut bacteria and weight
The mix of gut bacteria differs between people with and without obesity, although Cleveland Clinic notes that the reasons remain unclear. Part of the interest comes from fecal transplants, which move a whole community of gut microbes from one person to another; Cleveland Clinic reports that some recipients without overweight became overweight over time. A probiotic capsule is very different. As Cleveland Clinic’s Gail Cresci explains, a supplement delivers one or a few microbes, a fraction of what a transplant carries. A 2020 study of synbiotics, which combine probiotics with prebiotic fiber, found no effect on weight loss or body composition. Cresci’s practical advice is about food: friendly gut bacteria thrive on high-fiber foods such as fruits, vegetables, whole grains and legumes.
Probiotics and weight loss: strains that have been tested
- Lactobacillus gasseri SBT2055: 87 Japanese adults drank fermented milk with or without the strain for 12 weeks. The probiotic group lost about 1.1 kg from baseline while the control group did not change significantly. The authors worked for Snow Brand, the dairy company behind the strain.
- Lactobacillus rhamnosus CGMCC1.3724: in a 24-week trial with Nestle researchers, obese adults followed a calorie-reduced diet. Weight loss did not differ overall; women taking the probiotic lost more than women on placebo, and men did not differ.
- L. curvatus HY7601 plus L. plantarum KY1032: 72 adults with overweight were randomized for 12 weeks. Weight fell by 0.47 kg with the probiotic and rose by 0.93 kg with placebo. Seven of eight authors worked at the Korean company that makes the strains.
- Akkermansia muciniphila: a 2019 pilot with 32 completers found a 2.27 kg weight difference that was not statistically significant. Two authors co-founded a company developing the bacterium. See our Akkermansia guide.
Each result applies to that strain, in that form, in that population. A capsule listing “L. gasseri” without a strain code is not the same as SBT2055 in fermented milk. Our guide to probiotics for women explains how to read strain names.
What weight loss probiotic labels contain
Products marketed for weight management often combine probiotics with other active ingredients. Here is what three labels we carry list:
| Product | Probiotic content | Other actives | Label notes |
|---|---|---|---|
| Physician's Choice Probiotics for Weight Management | Six species, no strain codes, no CFU count | Greenselect green tea extract, apple cider vinegar extract, cayenne, inulin, acacia, enzymes | Consult a professional if pregnant, lactating or on medication |
| SkinnyFit NLP-1 | 12-species blend, no strain codes | 1,000 mg berberine extract, chicory root, turmeric | Do not use if pregnant, nursing or trying to conceive |
| Pendulum GLP-1 Probiotic | C. butyricum WB-STR-0006, A. muciniphila WB-STR-0001, B. infantis | Chicory inulin | Refrigerate; brand says not intended for weight loss |
Counts are not always comparable. Pendulum states potency in AFU (active fluorescent units), a flow-cytometry count that is often higher than the CFU plate counts other brands use, and some labels give a blend weight or no count at all.
Physician’s Choice Probiotics for Weight Management gets its “weight” angle mostly from non-probiotic ingredients. Greenselect is a green tea extract, not a probiotic, and ODS notes that green tea extract has been linked to liver damage in some people. SkinnyFit NLP-1 contains 1,000 mg of berberine per serving, which interacts with diabetes medicines and other drugs; read our berberine side effects guide first. The Pendulum GLP-1 Probiotic lists coded strains, but the brand’s own footnote says its claims are based on preclinical studies and that it is not intended for weight loss. None of these are GLP-1 medicines; our guide to GLP-1 support supplements explains the difference.
How the FTC views weight-loss claims
Supplement makers do not need FDA approval for their claims, but the Federal Trade Commission (FTC) polices advertising. Its “Gut Check” guide for media lists weight-loss claims that cannot be true, such as substantial weight loss no matter what you eat, permanent weight loss after you stop using a product, and substantial weight loss for all users. Probiotic marketing has drawn FTC action before: in 2010 Dannon settled FTC charges over digestive and immune claims for Activia and DanActive and agreed to back some future claims with at least two well-controlled human studies. Supplement labels that describe effects on the body must also carry the FDA disclaimer printed at the end of this article. Any promise of effortless weight loss from a probiotic is a red flag.
Safety and who should ask first
- Gas and bloating are the most common complaints, especially in the first weeks.
- People with weakened immune systems or serious illness face a higher risk of infection, per ODS and NCCIH.
- Anyone taking prescription medicines, particularly with products that add berberine or green tea extract.
- People who are pregnant, nursing or trying to conceive; several labels say not to use them.
Diet, activity and sleep remain the foundation of weight management. If you want a probiotic for digestive reasons, our guide to probiotics for bloating covers that evidence, and our appetite control category lists the labels above.
Frequently Asked Questions
Do probiotics help you lose weight?
Only slightly, on average. Meta-analyses found differences of about 0.6 to 0.9 kg versus placebo in short trials, and results vary by strain.
Which probiotic strains have been studied for weight?
Examples include L. gasseri SBT2055, L. rhamnosus CGMCC1.3724, L. curvatus HY7601 with L. plantarum KY1032, and Akkermansia muciniphila. Many trials were small and industry-funded.
Is a weight loss probiotic the same as a GLP-1 drug?
No. Probiotics sold as GLP-1 support are dietary supplements, not GLP-1 medicines, and Pendulum says its product is not intended for weight loss.
How long did weight studies of probiotics last?
Most ran 3 to 12 weeks; one ran 24 weeks. Long-term effects are unknown.
Can probiotics cause weight gain?
The meta-analyses above did not report weight gain on average, but calories from gummies or drinks still count.
Are probiotics for weight loss safe?
Most healthy adults have mild side effects such as gas. Check other ingredients such as berberine or green tea extract, and ask a clinician if you take medicines.
Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed September 2026.
Related guides: Probiotics for Women: How to Read Strains, CFU and Probiotic Gummy Labels, Akkermansia Probiotic: What It Is, Live vs Pasteurized and How to Read the Label, What Are “GLP-1 Support” Supplements? Reading the Label Honestly.