Fubrick tea attenuates high-fat diet induced fat deposition and metabolic disorder by regulating gut microbiota and caffeine metabolism

Fubrick tea aqueous extract (FTEs) has been reported to improve lipid metabolism and gut microbiota communities in mice and humans. However, it is still unclear how FTEs prevents obesity through gut microbiota, and whether some other regulatory mechanisms are involved in the process. Here, we found that FTEs supplementation effectively alleviated the body weight gain, visceral fat accumulation, dyslipidemia, and impaired glucose tolerance induced by a high-fat diet (HFD), and fecal microbiota transplantation (FMT) from FTEs-treated mice showed similar protective effects as FTEs supplementation in mice fed with a HFD. The results confirmed that gut microbiota played key roles in attenuating HFD-induced fat deposition and metabolic disorder. In particular, FTEs reversed HFD-induced gut microbiota dysbiosis via increasing the relative abundances of Bacteroides, Adlercreutzia, Alistipes, Parabacteroides, and norank_f_Lachnospiraceae, and reducing that of Staphylococcus. Interestingly, FTEs could still alleviate HFD-induced lipid accumulation in mice treated with antibiotics, which had increased relative abundances of Bacteroidetes, Bacteroides, and Bacteroides_uniformis sp. In addition, supplementation with FTEs also modified the serum metabolome, especially the "caffeine metabolism" pathway. Furthermore, FTEs supplementation increased the concentrations of caffeine, theophylline, and theobromine in serum, which were positively correlated with an abundance of norank_f_Lachnospiraceae. Overall, FTEs exerts beneficial effects against obesity induced by HFD, and the underlying mechanism is partially related to the reprogramming of intestinal microbiota, while the metabolism of caffeine in FTEs also played an important role in the process. This study provides a theoretical basis for the further study of the anti-obesity effects of FTEs and the consideration of gut microbiota as a potential target for the treatment of obesity induced by a HFD.