The gut microbiota and metabolomics in the pathogenesis of type 2 diabetes mellitus combined with coronary atherosclerotic heart disease

To investigate the characteristics of intestinal bacteria and their metabolites in healthy controls (CONs) compared with individuals with type 2 diabetes mellitus (T2DM) and individuals with type 2 diabetes mellitus combined with coronary atherosclerotic heart disease (T2DM-CAD). Thirty samples were collected from 10 healthy people, 10 T2DM patients, and 10 T2DM-CAD patients. We determined the gut bacterial composition via metagenomic sequencing analysis and analyzed the gut microbes and their metabolomic changes via metabolomics. The potential key gut microbes and metabolites were explored with random forest and receiver operating characteristic (ROC) curve analyses. Finally, Spearman correlation analysis and linear regression were used to identify the correlations between the gut bacteria and metabolites. Eight gut microorganisms with diagnostic significance were screened out, including Prevotella disiens, Bacteroides sp._AM25_34, Paraprevotella clara, Bacteroides sp._CAG_875, Sutterella wadsworthensis, Prevotella sp. 885, Ruminococcus sp. AM42_11 and Anaerobutyricum hallii. Meanwhile, eight characteristic metabolites were identified, including fructose, salicyluric acid, 12-ketoLCA, pyroglutamic acid, glutamic acid, suberic acid, gallic acid and adipic acid. Additionally, the correlations between the above differential gut microbiota and characteristic metabolites were clarified. Our study revealed that gut flora such as g-Bacteroides, Alistipes_putredinis_CAG_67, and Alistipes_putredinis may be key flora, and that fructose, gallic acid, sebacic acid, and 12-ketoLCA may be key metabolites involved in the pathology of T2DM and T2DM-CAD.