<i>Bacillus subtilis</i> -Fermented <i>Cynanchum atratum</i> Ameliorates Lipid Accumulation in Mice with Obesity Induced by High-Fat, High-Fructose Diet: Implications for Gut Microbiota and Peripheral Serotonin

Objective: The aim of this study was to evaluate the effects of Bacillus subtilis -fermented Cynanchum atratum (BSCA) on excessive lipid accumulation using a mouse model. Methods: The anti-fatty liver and anti-hyperlipidemic potentials of BSCA were evaluated in mice fed a high-fat, high-fructose diet (HFHFD) for 10 weeks. Results: In long-term HFHFD-fed mice, BSCA treatment resulted in notable decreases in body, liver, and fat masses compared to those in the HFHFD control group. Additionally, BSCA lowered the serum levels of aspartate transaminase, alanine transaminase, triglycerides, and total cholesterol, with no significant changes observed in HDL or LDL levels. BSCA also restored the gut microbiota diversity and increased peripheral serotonin levels, which were reduced by the HFHFD. Conclusions: BSCA exhibits anti-fatty liver and anti-hyperlipidemic activities by inhibiting lipogenesis, a process associated with alterations in gut microbiota composition and increased serotonin levels. These findings suggest that fermented C. atratum holds promise as an herbal medicine for treating chronic metabolic disorders, including metabolic dysfunction-associated fatty liver disease, metabolic syndrome, and obesity.