CXCL8 and type 2 diabetes mellitus: In our previous studies, the relative abundance of 33 bacterial genera-level and 9 bacterial species-level OTUs showed significant differences between T2DM patients and HCs (Figs. S1 and S2), 21 bacterial genera-level and 10 bacterial species-level OTUs showed significant differences between the WIL8 and NIL8 T2DM subgroups (Figs. S3 and S4), and 18 bacterial genera were predictors of urinary IL-8 in a stepwise regression analysis (Table S1).