Supplement analysis backed by scientific evidence · PT

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Limited evidenceWeight management

Lactobacillus Gasseri

Marketed hard as a "belly fat probiotic" on the strength of two Japanese fermented-milk trials of strain SBT2055. The weight loss in those trials was about 1 kg over 12 weeks, it reversed completely after stopping, and independent replication in other populations is thin.

What the science says

  • Reduces abdominal visceral fat Limited evidence

    In a 12-week RCT of 87 adults with obese tendencies, fermented milk with L. gasseri SBT2055 at 100 million CFU/g reduced visceral fat area by about 4.6% and body weight by roughly 1.4% versus essentially no change on placebo. A larger 210-person trial confirmed similar magnitude (visceral fat area down 8.5% at 10 billion CFU/day), but abdominal fat returned toward baseline within 4 weeks of stopping.

  • Produces clinically meaningful weight loss Limited evidence

    The best-case result is roughly 1-1.5 kg over 12 weeks — below the ~5% threshold generally considered clinically meaningful, and smaller than what a modest calorie deficit achieves. Trials were conducted in Japanese adults using a dairy vehicle and mostly funded by the dairy manufacturer; results in Western populations and in capsule form are far less consistent.

  • Supports vaginal and urogenital health Limited evidence

    L. gasseri is a normal dominant species of the healthy vaginal microbiome and appears in multi-strain products for bacterial vaginosis recurrence, but trials are small, heterogeneous and usually combine it with L. rhamnosus or L. crispatus, so a specific effect for gasseri alone is not established.

  • Suppresses appetite via leptin or GLP-1 Limited evidence

    Mechanistic claims come from rodent studies and in vitro work showing altered fat emulsion size and increased fecal fat excretion. No human trial has shown meaningful appetite suppression, and this marketing angle outruns the data badly.

Dosage & safety

Studied doseThe trials used fermented milk providing roughly 10 billion CFU/day (SBT2055), taken as 200 g of drink twice daily for 12 weeks. Capsule products typically supply 1-10 billion CFU/day, which has not been separately validated. Benefits disappear within about 4 weeks of discontinuation, so it is an indefinite commitment, not a course.
SafetyWell tolerated, with transient bloating or gas. Avoid in severely immunocompromised, catheterized or critically ill people because of rare probiotic bacteremia. The dairy vehicle used in trials adds calories, lactose and sugar. No interactions with weight-loss drugs are established, and this should not be substituted for evidence-based obesity treatment.

Scientific references

Where to buy

Humanx, Lactobacillus Gasseri & Reuteri+, 30 Veggie Capsules

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