Lacticaseibacillus rhamnosus LR.KY16 improves depression by promoting intestinal secretion of 5-HTP and altering the gut microbiota

Increasing researches suggest a connection between gut microbiota and depressive disorders. Targeted changes to the intestinal flora may contribute to alleviating anxiety and depression. This study aimed to identify probiotics that could attenuate stress-induced abnormal behavior and explore potential mechanisms..BALB/c male mice chronically exposed to stress were supplemented with viable Lacticaseibacillus rhamnosus LR.KY16 for 5 weeks. Mouse behaviors; serum corticosterone, inflammation cytokines, and 5-hydroxytryptophan (5-HTP) or 5-hydroxytryptamine (5-HT) levels; and fecal microbial composition were measured. Additionally, antibiotic susceptibility test and hemolysis test were performed to evaluate the safety of LR.KY16 in vitro.