Tea–Gut Microbiota Interactions: Mechanisms, Health Benefits, and Future Perspectives

Tea, derived from Camellia sinensis, is one of the most widely consumed beverages worldwide and is rich in bioactive compounds, particularly polyphenols, that exhibit significant health-promoting properties. Growing evidence indicates that tea polyphenols interact extensively with the human gut microbiota, a complex microbial ecosystem essential for maintaining intestinal homeostasis, metabolic regulation, and immune function. Tea polyphenols, including catechins and theaflavins, are poorly absorbed in the small intestine and reach the colon, where they undergo microbial biotransformation into bioactive metabolites. These interactions are bidirectional, as gut microorganisms metabolize tea polyphenols while tea-derived compounds selectively modulate the gut microbial community by promoting beneficial bacteria such as Bifidobacterium, Lactobacillus, and Akkermansia muciniphila and suppressing pathogenic microorganisms. Such microbial modulation enhances short-chain fatty acid production, strengthens intestinal barrier function, and contributes to improved metabolic health, immune regulation, and a reduced risk of several chronic diseases. Emerging evidence further suggests that the microbiota-modulating effects of tea vary among green, black, oolong, and fermented teas because of differences in their polyphenolic composition and processing methods. However, most available evidence is derived from in vitro and animal studies, whereas robust human clinical trials remain limited. Variations in tea composition, dosage, and individual gut microbial profiles further complicate the interpretation of existing findings. Collectively, current evidence supports tea as a promising dietary modulator of the gut microbiota, although further mechanistic and clinical investigations are required to establish its therapeutic potential and facilitate microbiome-based nutritional interventions