关键词: 茯砖茶多糖；2型糖尿病；肠道菌群；代谢物

Abstract: Objective: This study was designed to investigate the effects of Fu brick tea polysaccharides (FTP) on glucose and lipid metabolism in type 2 diabetes mellitus (T2DM) mice, providing a theoretical basis for the development of FTP-related functional foods. Methods: A mouse model of T2DM was established by feeding a high-fat diet combined with intraperitoneal injection of streptozotocin (50 mg/kg). The mice were divided into four groups: normal control (NC), model (T2DM), metformin (Met), and FTP. The NC and T2DM groups received saline by gavage, the Met group metformin (100 mg/kg), and the FTP group FTP (200 mg/kg). The administration period lasted for 8 weeks. Serum levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), glucagon-like peptide 1 (GLP-1), interleukin‑6 (IL‑6), and tumor necrosis factor‑α (TNF‑α) were measured to evaluate glucose-lipid metabolism and inflammatory responses. Additionally, the gut microbiota and metabolite composition were analyzed by 16S rDNA sequencing and untargeted metabolomics, respectively. Results: FTP inhibited body mass loss and hyperglycemia in T2DM mice, and improved disordered glucose and lipid metabolism and inflammatory responses. Compared with the T2DM group, FTP intervention decreased serum TC, TG, LDL‑C, IL‑6, and TNF‑α by 32.3%, 33.0%, 36.6%, 21.8%, and 15.3%, respectively and increased HDL‑C by 20.8%. In addition, FTP altered the composition and abundance of the gut microbiota, notably increasing the relative abundance of beneficial genera such as Bacteroides, Bifidobacterium, and Akkermansia, while decreasing the relative abundance of potentially harmful taxa including norank_f__Eubacterium_coprostanoligenes_group, Lachnospiraceae_UCG-006 and Allobaculum, thereby regulating pathways including linoleic acid metabolism; porphyrin metabolism, arginine biosynthesis; alanine, aspartate and glutamate metabolism; and cysteine and methionine metabolism. Moreover, it promoted the production of beneficial metabolites such as short-chain fatty acids (SCFAs), ultimately ameliorating diabetic symptoms. Conclusion: FTP ameliorated glucose and lipid metabolic disorders in T2DM mice by remodeling the gut microbiota and its metabolites. This finding will provide a new perspective and theoretical basis for the application of FTP in functional foods.

Key words: Fu brick tea polysaccharides; type 2 diabetes; gut microbiota; metabolites