Novel markers to evaluate the disease activity of rheumatoid arthritis based on some intestinal flora imbalance, abnormal immune cells and cytokines

Objective: We aimed to investigate the changes of gut microbiota and analyze the correlation of gut microbiota with lymphocyte subsets, cytokines and clinical indicators in RA patients with active and remission stage, and to find new makers to evaluate disease activity of RA. Method: The intestinal flora of subjects was collected for 16SrRNA gene sequencing. Flow cytometry to detect the number of lymphocyte subsets and their ability to secrete cytokines. ELISA was used to test the serum levels of cytokines. Result: The richness and diversity of gut microbiota were significantly decreased in active and remission stages of RA patients compared to HCs. Most importantly, at the phylum level, the relative abundance of Bacteroidetes and Actinobacteria was decreased in RA patients with remission stage, while the relative abundance of Fusobacteria was increased in RA patients with active compared to HCs. At the genus level, the relative abundance of Ruminococcaceae_Ruminococcus and Bacteroides was decreased, while the abundance of Megamonas was increased in RA patients with active and remission stage compared to HCs. Intestinal flora was directly correlated with lymphocytes, cytokines and clinical indicators in active and remission stages of RA patients. Conclusion: These results suggest that the changes of gut microbiota can lead to imbalances of CD4 + T, CD8 + T, memory B-cell subsets and cytokines that influence disease activity of RA patients. Interestingly, some intestinal flora may be used as markers to evaluate disease activity in RA patients.