Electroacupuncture Improves Myocardial Fibrosis in Association With Intestinal Flora and Metabolic Modulation in Mice

<b>Objective:</b> This study investigates the reparative effect of electroacupuncture on myocardial fibrosis (MF) in mice and explores its impact on intestinal flora and metabolism profile. This examines an investigation into the biological mechanisms underlying electroacupuncture's efficacy in treating MF in mice. <b>Methods:</b> Twenty-four male Kunming mice (27-34 g) were randomized into three groups: normal control (NC, <i>n</i> = 8), MF model (MF, <i>n</i> = 8), and electroacupuncture treatment (EA, <i>n</i> = 8). MF and EA groups received daily subcutaneous ISO injections (25 mg/kg) at the nape for 5 days; NC mice received saline. The EA group underwent 14 days of EA at PC6 (Neiguan). Cardiac function, intestinal flora, and metabolites were assessed post-treatment. <b>Results:</b> EA significantly reduced cardiac weight index (CWI), collagen volume fraction (CVF), and serum procollagen III N-terminal propeptide (PIIINP) and improved left ventricular ejection fraction (LVEF) and shortening fraction (LVFS) (<i>p</i> < 0.05). Gut microbiota analysis revealed distinct composition shifts: EA restored <i>Bacteroidota</i> abundance and lowered <i>Firmicutes</i>/<i>Bacteroidota</i> ratios, resembling NC profiles. Notably, differential bacteria (e.g., <i>Staphylococcus lentus</i>, <i>Xylanophilum</i>) correlated with PIIINP, CVF, and cardiac function. Metabolomics identified reduced TMAO, phenylalanine, acetone, and lactic acid in EA vs. MF (<i>p</i> < 0.05). Negative correlations included <i>Stricto-1</i> vs. phenylalanine and <i>Rodentium</i> vs. acetone. <b>Conclusion:</b> EA ameliorates ISO-induced MF in mice by modulating gut microbiota structure and metabolic profiles, suggesting a microbiota-metabolite axis mediates its therapeutic effects.