Berberine Alleviates Chronic Restraint Stress‐Induced Depression‐Like Behavior by Modulating Gut Microbiota and SCFA Production in Mice

The exact mechanism by which berberine alleviates depression remains unclear. In this study, we explored the relationship between the antidepressant effect of berberine and the microbiota-brain-gut axis. The levels of IL-1β, TNF-α, IL-6, corticosterone, serotonin, and brain-derived neurotrophic factor (BDNF) were quantified using enzyme-linked immunosorbent assays (ELISA) and Western blotting. Variations in the composition of the gut microbiota were examined using 16S rRNA gene sequencing. Berberine significantly mitigated depressive behaviors in mice with CRS, as manifested by increased total distance traveled and central zone duration in the open-field examination, increased time and number of entries into the outstretched arms during the elevated and maze tests, and an increase in the exercise time during the tail suspension and forced swimming tests. Histopathological analysis indicated that berberine ameliorated CRS-induced hippocampal and colonic damage in mice. Additionally, berberine substantially restrained the generation of proinflammatory cytokines and corticosterone in mice with CRS, while increasing the levels of BDNF and serotonin. Importantly, berberine significantly ameliorated CRS-induced depression-like behaviors (p < 0.01) and restored gut microbial diversity and short-chain fatty acid (SCFA) levels (fold-change: acetate 1.8-fold, butyrate 2.2-fold; p < 0.05). Furthermore, berberine restored the CRS-induced alterations in SCFA production. Our results indicate that berberine may exert antidepressant effects via a pleiotropic mechanism that modulates the microbiome-brain-gut axis.