Polyphenols from Fu Brick Tea Reduce Obesity via Modulation of Gut Microbiota and Gut Microbiota-Related Intestinal Oxidative Stress and Barrier Function

Fu brick tea (FBT) is a microbial-fermented tea, which is produced by the solid-state fermentation of tea leaves. Previous studies have proved that FBT aqueous extracts could attenuate obesity and gut microbiota dysbiosis. However, the bioactive components in FBT that contribute to these activities remain unclear. In this study, we aimed to investigate the effects of FBT polyphenols (FBTPs) on obesity, gut microbiota, and gut microbiota-related intestinal oxidative stress and barrier function and to further investigate whether the antiobesity effect of FBTPs was dependent on the alteration of gut microbiota. The results showed that FBTP supplementation effectively attenuated obesity in high-fat diet (HFD)-fed rats. FBTP supplementation improved the intestinal oxidative stress and intestinal barrier function, including intestinal inflammation and the integrity of the intestinal barrier. Furthermore, FBTP intervention significantly attenuated HFD-induced gut microbiota dysbiosis, characterized by increased phylogenetic diversity and decreased Firmicutes/Bacteroidetes ratio. Certain core microbes, including Akkermansia muciniphila, Alloprevotella, Bacteroides, and Faecalibaculum, were also found to be improved by FBTPs. Moreover, the antiobesity effect of FBTPs was gut microbiota-dependent, as demonstrated by a fecal microbiota transplantation experiment. Collectively, we concluded that FBTPs reduced obesity by modulating the gut microbiota and gut microbiota-related intestinal oxidative stress and barrier function. Therefore, FBTPs may be used as prebiotic agents to treat obesity and gut microbiota dysbiosis in obese individuals.