The results of this study demonstrate that asiaticoside can improve the gut microbial structure in CUMS mice, alter SCFA metabolism, regulate the HPA axis and inflammatory factor levels, upregulate hippocampal BDNF and 5-HT1A protein expression, and increase serum 5-HT concentration, thereby improving depression-like behavior in CUMS mice. Here, HTR1A is linked to depressive disorder.