The significant association between abundant Prevotella sp., particularly Prevotella copri, and RA and ankylosing spondylitis has been consistently demonstrated through the identification of sequence homology between RA-specific autoantigens (N-acetylglucosamine-6-sulfatase and filamin A) and epitopes (sulfatase proteins) in P. copri proteins.30 Additionally, we observed a significant increase in the abundance of intestinal B. fragilis after infection, particularly in the Abx group, which is a characteristic of the Prevotella-dominated gut environment. Here, FLNA is linked to rheumatoid arthritis.