Green tea polyphenols reduce obesity in high-fat diet-induced mice by modulating intestinal microbiota composition

In this study, the modulatory effect of green tea polyphenols (GTP) on human intestinal microbiota was investigated. Firstly, germ-free mice were inoculated with faecal suspension derived from healthy volunteers to obtain human flora-associated (HFA) mice model. When the high-fat diet-induced obese mice model was successfully established, they were randomly divided into high-fat diet group (HFD) and high-fat diet group with GTP (HFD-GTP), and the shifts in relative abundance of the dominant taxa at the phylum, family and genus levels were studied by high-throughput sequencing. The diversity of the total bacterial community reached the maximum after GTP treatment for 3weeks, and then decreased when the mice were fed without GTP. Despite interindividual variation, the relative abundance of Bacteroidetes increased from 0.56 +/- 0.06 (1st week) to 0.60 +/- 0.05 (3th week), while Firmicutes decreased from 0.42 +/- 0.06 to 0.37 +/- 0.02. Interestingly, certain bacterial communities such as Bacteroidetes and Proteobacteria still increased and Firmicutes showed a decreasing trend when the mice were fed without GTP (4th week). The results showed that GTP benefits the stability of certain gut microbiota, especially in an environment-triggered microbial imbalance; therefore, it may have prebiotic-like activity contributing to the prevention of obesity.