The Regulation Effect And Metabolic Analysis Of Atractylodis Rhizoma Polysaccharide On Intestinal Microbes In T2DM Patients

Type 2 diabetes mellitus accounts for more than 90%of diabetes mellitus,and has become a global public health problem that seriously endangers human physical and mental health.Intestinal microorganisms and their metabolites are important factors that mediate its occurrence and development.Atractylodis Rhizoma,as a traditional Chinese medicine which can be used as health food,has a good hypoglycemic effect.However,there are few reports on the treatment of diabetes with Atractylodis Rhizoma polysaccharide on intestinal microbes regulation.Therefore,this study took Atractylodis Rhizoma polysaccharide（ARP）as the research object,based on the in vitro fermentation model,using 16S r RNA gene sequencing,GC-MS and HPLC-MS techniques to explore the effects of Atractylodis Rhizoma polysaccharide on intestinal microbes,gas production and metabolites of T2DM patients,and to evaluate its potential antioxidant and anti-glycosylation capabilities.So as to expand the understanding of the functional activity of Atractylodis Rhizoma polysaccharides,and provide a theoretical reference for the development and utilization of plant-derived homologous polysaccharides.The specific research contents and results are as follows:1.Simulated digestion of Atractylodis Rhizoma polysaccharide in vitro:After simulated gastrointestinal digestion,only 1.092%of Atractylodis Rhizoma polysaccharide was degraded,and the molecular weight of Atractylodis Rhizoma polysaccharide decreased obviously after in vitro fermentation,which indicated that Atractylodis Rhizoma polysaccharide was hardly degraded when it passed through stomach and small intestine,and could reach the interaction between colon and intestinal microorganisms.2.Antioxidant capacity of Atractylodis Rhizoma polysaccharide in vitro fermentation broth:Atractylodis Rhizoma polysaccharide can significantly improve the total reduction capacity of feces in vitro fermentation broth of healthy people（normal group）and patients with type 2 diabetes（disease group）,and can effectively remove DPPH free radical and hydroxyl free radical in feces in vitro fermentation broth.3.Atractylodis Rhizoma polysaccharide regulates the gas production of intestinal bacteria in vitro fermentation:The gas production of the disease group without adding Atractylodis Rhizoma polysaccharide is lower than that of the normal group,and the in vitro fermentation of Atractylodis Rhizoma polysaccharide increases the gas production volume of the two groups.Among them,the volume of H₂S in the normal group decreased,while the volumes of CO₂,H₂and CH₄ increased.The volumes of four gases in the disease group all increased.4.Atractylodis Rhizoma polysaccharide regulates intestinal microbial community:Atractylodis Rhizoma polysaccharide can regulate the microbial structure of human feces in vitro fermentation,increase the abundance of Firmicutes and Bacteroides in normal group and disease group,and decrease the abundance of Proteobacteria.In addition,the levels of Bifidobacterium,Faecalibacterium,Megamonas,Bifidobacterium pseudocatenulatum DSM20438 JCM 1200 LMG 10505 and Bacteroides vulgatus increased,while the levels of Escherichia-Shigella and Escherichia coli decreased.This is closely related to Biosynthesis of amino acids,ABC transporters and other metabolic pathways.5.Atractylodis Rhizoma polysaccharide regulates intestinal microbial metabolism:Atractylodis Rhizoma polysaccharide jointly increased the contents of acetic acid,propionic acid,4-aminobutyric acid and inositol in the in vitro fermentation broth of feces in normal and disease groups.And the contents of L-5-oxoproline,lactic acid,alanine and threonine in normal group,and butyric acid,lactic acid in disease group were increased respectively.At the same time,Atractylodis Rhizoma polysaccharide decreased the contents of isovaleric acid,butyric acid,isobutyric acid,5-aminovaleric acid and phenylacetic acid in normal group,and the contents of valine,leucine,isoleucine,alanine,putrescine,glutamic acid,phenylalanine and ornithine in disease group.They are mainly related to amino acid metabolic pathways such as phenylalanine metabolism,arginine biosynthesis,arginine and proline metabolism,and inositol phosphate metabolism.6.Atractylodis Rhizoma polysaccharide regulates the anti-glycation effect through intestinal microbial metabolism:Atractylodis Rhizoma polysaccharide and three metabolites inositol,acetic acid and propionic acid can inhibit the generation of AGEs;Inhibit the carbonylation of protein;The content of free sulfhydryl in protein was increased,but the effect was not significant;Inhibit the formation of amyloidβ-cross-linked structure;To some extent,the hydrophobicity of protein caused by glycosylation was inhibited;Prevent the conformational changes ofα-helix andβ-sheet induced by glycosylation.To sum up,the hypoglycemic mechanism of Atractylodis Rhizoma polysaccharide may be related to increasing the abundance of Bifidobacterium,Faecalibacterium,Megamonas,decreasing the abundance of Escherichia-Shigella and Escherichia coli,regulating microbial gas production,and further improving antioxidant activity and anti-glycosylation ability by increasing microbial metabolites such as acetic acid,propionic acid,inositol and 4-aminobutyric acid,so as to exert the hypoglycemic effect together.