Hypoglycemic and Hypolipidemic Mechanism of Tea Polysaccharides on Type 2 Diabetic Rats <i>via</i> Gut Microbiota and Metabolism Alteration

Background: Diabetes mellitus is a serious threat to human health. Tea is cultivated around the world and its polysaccharide components are reported to be an effective approach for managing type 2 diabetes with fewer adverse effects than medication.Methods: To examine the therapeutic effect of tea polysaccharides on diabetes, a type 2 diabetic rat model was generated and 16S rRNA sequencing and metabolomics were used to investigate the variation of gut microbiota and the metabolites profiles of diabetic rats after intervention of tea polysaccharides.Findings: We showed that tea polysaccharides remarkably decreased fasting blood glucose and the levels of total cholesterol, total triglyceride, low-density lipoprotein cholesterol and free fatty acid of type 2 diabetic rats. And tea polysaccharides maintained the diversity of gut microbiota and restored the relative abundance of some bacterial genera (Lachnospira, Victivallis, Roseburia and Fluviicola) which was reduced by diabetes. According to metabolomics analysis, we found that amino acid and other related metabolites was influenced by tea polysaccharides intervention.Interpretation: Correlation analysis among metabolites, gut microbiota, and parameters of hypoglycemic indicated that tea polysaccharides had hypoglycemic and hypolipidemic effect on type 2 diabetes via the modulation of gut microbiota and the improvement of host metabolism.Funding Statement: The financial support from National Natural Science Foundation of China for4 Distinguished Young Scholars (31825020), the Program for National Key R&D Program of China (2017YFD0400203), the Project of Academic Leaders of the Major Disciplines in Jiangxi Province (20162BCB22008), Outstanding Science and Technology Innovation Team Project in Jiangxi Province (20165BCB19001), Collaborative Project in Agriculture and Food Field between China and Canada (2017ZJGH0102001), Graduate Student Innovation Special Fund Support in Jiangxi Province (YC2018-S004), is gratefully acknowledged.Declaration of Interests: The authors declare that no conflict of interests.Ethics Approval Statement: All animals and laboratory conditions in this study were performed according to the National Institutes of Health Guidelines on the Use of Laboratory Animals (NIH publication No. 85-23, revised 1996). All experiments were approved by the Animal Care Review Committee, Nanchang University.