Green Tea Polyphenols Modulate Colonic Microbiota Diversity and Lipid Metabolism in High‐Fat Diet Treated HFA Mice

There is an increasing interest in the effect of dietary polyphenols on the intestinal microbiota and the possible associations between this effect and the development of obesity. However, limited information is available on how these polyphenols affect the gut microbiota and lipid metabolism. The co‐action of a high‐fat diet (HFD) and tea polyphenol (TP) on gut microbiota and lipid metabolism using a human flora‐associated (HFA) C57BL/6J mice model is studied. TP reduced serum total cholesterol, triglyceride, low density lipoprotein, glucose (GLU) and insulin (INS) levels of HFD mice in a dose‐dependent manner (P< 0.01). TP also significantly increased acetic acid and butyric acid levels in HFA mice. 16S rRNA V3 region Polymerase Chain Reaction‐Denaturing Gradient Gel Electrophoresis (PCR‐DGGE) profiles showed that HFD mice had significantly reduced microbial diversity. This reduction could be alleviated by TP, with a significant increase in the richness and diversity of colonic microbiota in the high‐fat diet with 0.2% TP (TPM) and high‐fat diet with 0.05% TP (TPL) groups (P< 0.05). 454 pyrosequencing analysis showed that the HFD group had a significant increase in the Bacteroidetes to Firmicutes (F/B) ratio (P< 0.001), which could effectively be reversed by TP. The results showed that the changes in composition and diversity of colonic microbiota by TP administration suppressed the host body weight and blood lipid increase in high‐fat diet HFA mice. A high fat diet significantly impacted gut microbiota composition and lipid metabolism in human flora‐associated mice, which were largely ameliorated by tea polyphenol (TP). Therefore, TPs may be effectively used in controlling or treating obesity, hyperlipidemia and other related metabolic diseases.