Abstract: Polyphenols, a class of plant secondary metabolites, are widely present in the human diet and can be divided into three categories: phenolic acids, polymer tannin and flavonoids. Polyphenols and their gut flora metabolites can selectively adjust the growth of susceptible microorganisms in the gut, promote the growth of beneficial bacteria (such as lactic acid bacteria), and inhibit the proliferation of harmful bacteria, thus causing intestinal micro-ecological changes. Such changes have an important impact on host energy metabolism, which may be achieved through the following aspects: 1) changes in intestinal microbial number and species alter microbial metabolism and the types and quantities of produced enzymes; 2) polyphenol metabolites can also act on bacterial cell surface to inhibit enzyme activities, thereby influencing energy metabolism and reducing fat deposition; 3) polyphenols regulate energy metabolism by interfering with the human intestinal flora, which can provide new ideas to prevent and treat obesity and related diseases. In this paper, we review the mechanism by which polyphenols can reduce the incidence of obesity by modulating the intestinal flora.

Key words: polyphenols, intestinal flora, energy metabolism