In ET-L, gut bacteria in the T2DM group were positively correlated with glycolysis and gluconeogenesis, pyruvate metabolism, the tricarboxylic acid (TCA) cycle, and fat digestion and absorption, while carbohydrate metabolism, including starch, fructose, and mannose as well as galactose metabolism, pentose phosphate metabolism, amino acid metabolism, nucleotide metabolism, insulin signaling, and adenosine 5′ monophosphate-activated protein kinase (AMPK) signaling were negatively correlated (p < 0.00005; Figure 6A). This evidence concerns the gene INS and type 2 diabetes mellitus.