Research progress on the regulatory effect of tea components on gut microbiota and their health effects
Tea is one of the three popular beverages worldwide. According to different production and processing methods, tea can be divided into black tea, black tea, green tea, oolong tea, etc. Tea mainly contains chemical components such as tea polyphenols, alkaloids, amino acids, and polysaccharides, which have many activities such as lowering blood pressure, antioxidation, antibacterial, anti-inflammatory, anti fatigue, and lowering blood sugar, and can improve overall health. The nutritional components of tea have a bidirectional synergistic effect with the gut microbiota, jointly regulating the health of the body. Tea components are difficult to digest in the stomach and can be broken down by gut microbiota after entering the intestine, exerting a prebiotic effect. At present, research on the regulation of gut microbiota by tea components mainly focuses on tea polyphenols, tea polysaccharides, tea pigments, etc. These individual components or combinations can directly or indirectly regulate the host’s gut microbiota, thereby improving overall health.
The human gut has a large and complex microbial community, among which Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria are the main components of the gut microbiota. Moreover, there is a close relationship between intestinal flora and the health of biological organism. Disordered intestinal flora can induce obesity, diabetes and other diseases and their complications; The gut microbiota gut liver circulation directly affects the body’s absorption and metabolism of lipids; The gut microbiota can mediate the regulatory effect of the gut brain axis on brain neural activity, and may also have an impact on psychological disorders and their treatment. And the health promoting benefits of gut microbiota largely depend on the action of metabolites. The gut microbiota can metabolize and produce beneficial compounds, such as short chain fatty acids (SCFAs), which hinder pathogens, regulate immune responses, and promote the differentiation and proliferation of intestinal epithelial cells. It can also produce various metabolites such as bile acids, indole derivatives, and choline metabolites through metabolism, affecting gene expression and regulating downstream signaling pathways, thereby achieving a regulatory effect on the body’s health. The importance of gut microbiota for the physiological and psychological health of organisms is increasingly prominent. It forms a stable symbiotic relationship with the host, and any changes in the structure and abundance of the gut microbiota will have a significant impact on gut metabolic protection and other functions, thus directly affecting human health.
This article reviews the regulatory effects of tea polyphenols, tea pigments, tea polysaccharides, and tea seed saponins on gut microbiota and their health benefits. It elucidates the interrelationships between different tea components, gut microbiota, and body health, providing scientific references and theoretical basis for the systematic and scientific use of tea components to improve gut microbiota and enhance human health.

Various tea components such as tea polyphenols, tea polysaccharides, tea pigments, and tea saponins have prebiotic effects, which can improve body metabolism and promote health by regulating intestinal microbiota (see Figure 1). The main manifestation is that tea components can be converted into other bioactive substances by intestinal microbiota, thereby affecting body health. (2) Tea ingredients can promote the growth of beneficial bacteria and/or inhibit the growth of harmful bacteria, improving the gut microbiota. (3) The gut microbiota can produce specific metabolites and regulate the body’s metabolism through related signaling pathways, thereby affecting health. A new approach has been opened up to elucidate the health effects and mechanisms of tea components by targeting gut microbiota.
There are still some issues that need further in-depth research and exploration regarding the relationship between tea components, gut microbiota, and overall health. (1) The research on the regulation of gut microbiota by tea components mainly focuses on tea polyphenols, and there is relatively little research on the components such as tea polysaccharides and tea pigments. Whether there is synergy or mutual inhibition between different components in different types of tea still needs to be further studied. (2) The results of different studies using the same disease model show significant differences, and even contradictory outcomes. Further research is needed to clarify whether this is due to differences in intake doses or individual differences. (3) There are few reports on the complex bidirectional regulation between tea components and their transformation products and gut microbiota, as well as the regulatory mediators and underlying mechanisms. Existing research mostly focuses on phenomenological results, such as changes in bacterial abundance and host physiological and biochemical levels, with little exploration of the underlying mechanisms. However, the analysis of the underlying mechanisms by which tea components target gut microbiota to exert health regulatory effects is not deep enough, and the biochemical and molecular signaling pathways involved are particularly noteworthy. (4) Tea components can be broken down or transformed in the intestine, so combining metabolomics analysis can better capture changes in the intestinal metabolites of tea components and explain their potential mechanisms of action on host health. (5) Combining animal models with fecal fermentation can provide a more comprehensive understanding of the metabolism of tea components in the gut, as well as their impact on gut microbiota structure and overall health. In particular, the development of organoid culture technology will contribute to further research on the interaction mechanism between tea components and gut microbiota. (6) The continuous deepening of research on the gut microbiota and specific bacterial strains will help better elucidate the health effects of tea components targeting gut bacteria. In summary, accelerating the in-depth study of the mechanism by which tea components target gut microbiota to regulate body health will provide theoretical guidance for improving the human gut microbiota through tea drinking or tea products, thereby promoting body health, and provide scientific basis for the development of tea related health products.