FN1 and rheumatoid arthritis: Compared with the normal group, the expressions of MMP3 (Figure 8L) and Fibronectin (Figure 8M) in the synovial tissue and the CRP (Figure 8N) and RF (Figure 8O) levels in serum of CIA mice were increased, and HQC-FMT reversed the above indexes, The above results further indicated that HQC played an anti-RA role by regulating intestinal flora.