Synergistic Effects of Fu Brick Tea Extract and Millet on Antiobesity in High-Fat Diet-Fed Mice through Gut Microbiota Modulation and Activation of the Ffar2 – Gcg / Pyy Molecular Pathway

This study elucidates the antiobesity mechanism of the Fu brick tea extract–millet complex (FTE-M). FTE-M exhibited a dense and smooth microstructure, resulting in improved digestive properties compared with millet alone, including a reduced glycemic index and increased slowly digestible starch and resistant starch contents. In a 10-week high-fat diet mouse model, dietary supplementation with FTE-M inhibited small intestinal α-amylase activity, delayed starch digestion, and improved glucose and lipid metabolism while alleviating inflammation. FTE-M also modulated gut microbiota composition, normalized bile acid profiles, and enriched short-chain fatty acids (SCFAs)-producing bacteria, including Akkermansia, leading to a 2.49-fold increase in total SCFAs. Mechanistically, elevated SCFAs were associated with the activation of free fatty acid receptor 2 (Ffar2) and increased expression of glucagon (Gcg) and peptide YY (Pyy), contributing to enhanced satiety. These findings highlight the potential of combining traditional millet with bioactive components to enhance metabolic functionality, providing a theoretical basis for developing starch-based antiobesity foods.