Electroacupuncture prevents CUMS induced depressive-like behaviors by inhibiting microglia-mediated synaptic pruning induced by gut dysbiosis

Rationale Electroacupuncture (EA) has been widely used for depression treatment. Microbiota-gut-brain (MGB) axis plays a vital role in regulating emotional behaviors. However, the potential role of MGB axis in EA-mediated protective effects remains unclear. Methods The protective effects of EA in chronic unpredictable mild stress (CUMS) induced mice were evaluated, and the gut microbiota and metabolic profiles were analyzed. Fecal microbiota transplantation (FMT) was utilized to explore the role of MGB axis in the protective effects of EA. Analyses related to synaptic pruning mediated by microglia were conducted to explore the molecular mechanisms. Results In this study, EA treatment prevented depressive-like behaviors in CUMS mice. Mechanistically, EA ameliorated CUMS-induced gut microbiota dysbiosis and inflammation, and partially restored gut microbial metabolism, particularly affecting the abundance of Alistipes and taurine metabolism. Furthermore, EA significantly reduced systemic and hippocampal inflammation. It also attenuated aberrant synaptic pruning in the hippocampus. Moreover, FMT from CUMS mice induced depressive-like behaviors, gut inflammation and microglia-mediated aberrant synaptic pruning, whereas FMT from EA-treated donors exerted protective effects against these impairments. Conclusion Collectively, our findings suggest that EA prevented CUMS-induced depression-like behaviors and support the involvement of the MGB axis in its protective effects.