Probiotics

Do probiotics help you lose weight?

Updated 4 Nov 2026

Short answer

Only slightly, if at all, and the trials disagree.[1] Reviews of mixed strains found:

  • 15 trials with 957 people: 0.6 kg more weight lost than with placebo. The NIH fact sheet calls this effect small and of doubtful importance.[1]
  • 19 trials with 1412 people: a waist 0.82 cm smaller, and no change in weight or body mass index (BMI).[1]
  • 8 trials with 412 people with obesity: more weight lost and less belly fat, but no difference in BMI.[2]

Single strains also differ. In 210 adults with a lot of belly fat, fermented milk with Lactobacillus gasseri SBT2055 lowered belly fat by about 8% in 12 weeks.[1] In 125 adults with obesity, Lactobacillus rhamnosus CGMCC1.3724 for 24 weeks did not change weight loss overall, although women lost 2.6 kg more than with placebo.[1] See weight management.

Sources (2)

  1. Probiotics: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2025. ods.od.nih.gov
  2. Effects of oral supplementation of probiotics on body weight and visceral fat in obese patients: a meta-analysis and systematic review. Guo M, Li J, Zhang L, Chen C, Wei Y, Shen ZA Sci Rep, 2025. PMID 39984625

More about probiotics

What are probiotics?Do probiotics change your gut bacteria?Is a higher CFU count better?Which foods contain probiotics?What are probiotics used for?Do probiotics prevent diarrhea from antibiotics and C. difficile?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.