Physicochemical and anti-diabetic properties of Fu-brick tea proteins: the key role of amino acid metabolism and gut microbial transformation.

Source: PubMed, NCBI / U.S. National Library of Medicine

This study for the first time provides the chemical characterization of Fu-brick tea proteins (FTPr) and systematically investigates its metabolic fate and anti-diabetic mechanisms. FTPr is a protein-polyphenol complex containing 42.96% proteins with glutamate, aspartate and proline as predominant amino acids, and 13.19% bonded polyphenols. FTPr exhibits excellent thermal and solution stability, with a secondary structure comprising 37.60% α-helix and 24.80% β-sheet. In vitro gastrointestinal digestion metabolomics revealed that FTPr hydrolysis significantly altered amino acid metabolism, notably impacting tryptophan, arginine and branched-chain amino acid metabolism. Subsequent anaerobic fermentation by diabetic microbiota promoted the production of SCFAs and tryptophan-derived indoles. In vivo, FTPr ameliorated glucolipid disorders, insulin resistance, and hepatic steatosis in T2DM mice through gut microbiota remodeling and elevation of SCFAs and indoles. The defined chemical and functional properties of FTPr underscore its potential as a microbiota-targeting anti-diabetic agent and a strategy for tea waste utilization.