Beneficial effects of tea water extracts on the body weight and gut microbiota in C57BL/6J mice fed with a high-fat diet

Accumulative evidence has suggested that tea consumption has benefits in reducing body fat and alleviating metabolic syndrome. We hypothesize that benefits of tea consumption can be partially mediated by modulating intestinal microbiota via inhibiting the formation of lipopolysaccharides (LPS) and promoting the production of short chain fatty acids (SCFAs). C57BL/6J mice were fed a high fat diet with the addition of 1% water extracts of green tea, oolong tea and black tea. Results showed that the dietary supplementation of three tea water extracts equally improved the glucose tolerance and reduced a high fat diet-induced gain in weight, hepatic lipids, and white adipose tissue weights. This was accompanied by a significant reduction in plasma LPS and a significant increase in the production of SCFAs. The metagenomic analyses showed that the tea extracts changed the overall composition of gut microbiota and decreased the relative abundance of family Rikenellaceae and Desulfovibrionaceae. In addition, tea water extracts could also change the abundance of key operational taxonomic units (OTUs) including OTU473 (Alistipes), OTU229 (Rikenella), OTU179 (Ruminiclostridium) and OTU264 (Acetatifactor). In conclusion, three tea extracts could improve the glucose tolerance, induce the production of SCFAs and inhibit the production of endotoxin LPS, most likely mediated by modulating gut microbiota.