TFRC and arthritic joint disease: Mice intestinal luminal three SCFAs concentrations↑.Acetate, propionate: do not have a significant effect on arthritis.Butyrate: Tfr cell differentiation↑, Tfh cell differentiation↓, autophagy antibody IgG2a↓.Butyrate reduces the production of autoantibodies rather than immune complex induction to alleviate the development of arthritis; Restrict the development of GC during CIA initiation to inhibit the production of CII-specific IgG.