C2 and Other metabolic disease: norank_Erysipelotrichaceae, Roseburia, norank_f_Lachnospiraceae, Lachnospiraceae_UGC_006, unclassified_f_Ruminococcaceae, and Anaerotruncus were positively correlated with the genes encoded IgA (Ighvs), C2, Iftm1, pigR, and Anpep, which could result in metabolism disorder, stimulate pro-inflammatory cytokine production, and enhance the responses of T helper 17 cells.