Across 3 studies (all beneficial), moderate to small effects were observed for improved gut microbiota composition with Lactobacillus rhamnosus. No consistent dose, population, or study duration was reported, and all studies were either reviews or an animal model. The evidence base is too limited to define a typical effect magnitude or applicable population.
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). None of the included studies reported statistical significance — effect may be smaller than the predominant direction suggests. Two of the three studies were reviews (not human trials) and one was an animal study, limiting direct applicability to humans.
consuming Lactobacillus rhamnosus lysate powder ... improved gut microbiota composition
how the new approach could be involved in the gut microbiome modulation to prevent and treat gut dysbiosis
CDEE modulated gut microbiota that altered by HFD through an increased abundance of Lactobacillus reuteri compared with the HFD group
pretreatment with BL improved CR-induced gut microbiota dysbiosis by reducing the content of Proteobacteria, while increasing the content of Lactobacillus.