Independent, evidence-first guides to probiotics, the microbiome & weight-management research.
Strain hub

Probiotic Strains Guide

One of the biggest mistakes in probiotic marketing is treating all members of a species—or all probiotics—as if they have the same evidence.

Reviewed for source accuracy: September 8, 2026 · Evidence can change as new research is published.

Species are not the end of the name

A probiotic's identity can include genus, species and strain. Clinical findings may apply only to the strain actually tested.

Why this matters for weight research

NIH ODS summarizes a trial of Lactobacillus gasseri SBT2055 and a different trial of Lactobacillus rhamnosus CGMCC1.3724. The outcomes were not identical. That is a concrete reminder that “Lactobacillus” is not one intervention.

Featured strain guides

Lactobacillus gasseri →
Lactobacillus rhamnosus →

How to evaluate a study

Match the strain, dose, delivery format, population, duration and outcome to the claim being made. If several of those differ from the product in front of you, the evidence is indirect.