INS and type 2 diabetes mellitus: Using age- and sex-adjusted linear models in 58 health traits, Wang et al. noted 199 significant correlations of gut microbial vitamin pathways with diabetic traits: B2 and B9 biosynthetic pathways were inversely correlated with HOMA-IR, insulin, glucose, T2DM status, low density lipoprotein (LDL)-cholesterol, triglycerides, C-reactive protein (CRP), and body mass index (BMI), whereas B1 and B12 pathways remained positively correlated with HOMA-IR and insulin levels.