Polysaccharides from Fu brick tea ameliorate obesity by modulating gut microbiota and gut microbiota-related short chain fatty acid and amino acid metabolism

Fu brick tea (FBT) is a traditional tea manufactured by solid-state fermentation of tea leaves (Camellia sinensis). Although anti-obesity effects have been reported for FBT, the associated role of FBT polysaccharides (PSs) and the underlying mechanisms remain unknown. In this study, we found that FBTPSs inhibited obesity, hyperlipidemia, and inflammation; improved intestinal barrier function; and alleviated gut microbiota dysbiosis in high-fat diet-fed rats. Akkermansia muciniphila, Bacteroides, Parasutterella, Desulfovibrio, and Blautia were the core microbes regulated by FBTPSs. FBTPSs regulated the production of gut microbiota-related metabolites, including short-chain fatty acids (SCFAs), branched-chain amino acids, and aromatic amino acids throughout the development of obesity, and regulated the SCFA-GPR signaling pathway. FBTPS-treated fecal microbiota transplant ameliorated obesity, alleviated gut microbiota dysbiosis, and improved gut microbiota-associated metabolites, suggesting that the anti-obesity effect of FBTPSs was gut microbiota-dependent. FBTPSs may serve as novel prebiotic agents for the treatment of obesity and dysbiosis of gut microbiota.