Our correlation analysis of gut microbiota with clinical biochemical indices revealed that Megasphaera enriched in normal-weight T2DM was positively correlated with FBG, HbA1c, hs-CRP, and MCP-1, Negativicutes was positively correlated with FBG and HbA1c, and Acidaminococcus was negatively correlated with HDL-C. Here, CCL2 is linked to type 2 diabetes mellitus.