Advances in research on the modulatory effects of tea-based beverages on gut microbiota composition and immune homeostasis

Tea was recognized as a traditional beverage rich in various bioactive components， such as polyphenols， polysaccharides， tea pigments， and theanine， and its health benefits were closely associated with the modulation of gut microbiota. The metabolic characteristics of these major components were systematically reviewed， and the mechanisms by which tea consumption improved host health through reshaping the structure and diversity of gut microbiota and maintaining intestinal immune homeostasis were deeply explored. The immunomodulatory effects of tea based on gut microbiota regulation were particularly elucidated from three aspects： The enhancement of intestinal physical and immune barrier functions was achieved by promoting the expression of tight junction proteins； The regulation of immune cell differentiation and balance was mediated by the microbial metabolite short‑chain fatty acids； The systemic inflammatory responses were attenuated by inhibiting inflammatory signaling pathways such as TLR/NF‑κB. On this basis， the roles and molecular mechanisms of tea bioactive components in regulating gut microbiota homeostasis， improving intestinal metabolism， and alleviating inflammation‑related diseases were summarized. The scientific evidence was provided for gut microbiota‑targeted research on the health effects of tea and new strategies for promoting public health.