Abstract: Objective  To explore the effects of intestinal microecological modulators on the intestinal microbiome and immune microenvironment of patients with rheumatoid arthritis (RA). 
Methods  A total of 90 RA patients who were treated in our hospital were divided into 2 groups: control group (treated with oral methotrexate tablets, n=45) and observation group (treated with intestinal microecological modulators, n=45). The diversity of the intestinal microbiome was analyzed. The levels of immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) were detected by enzyme-linked immunosorbent assay (ELISA). The classification of diseases and disabilities in two groups was calculated before and after treatment. Disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR) and disease activity score 28 (DAS28) were used to assess overall health status. 
Results  After treatment, the evenness and richness of microbiome in two groups were increased compared with those before treatment, which were higher in the observation group than in the control group, IgA, IgM and IgG in two groups were increased compared with those before treatment, which were higher in the observation group than in the control group. The proportion of grade Ⅰ and Ⅱ patients in both groups was higher than that before treatment, and the proportion of grade Ⅲ and Ⅳ patients was lower than that before treatment (P＜0.05). After treatment, the significant efficiency and total effective rate in the observation group were higher than those in the control group, while the inefficiency in the observation group was lower than that in the control group; the disease activity score in the observation group was higher than that in the control group (P＜0.05). 
Conclusion  Intestinal microecological modulators can effectively control the occurrence and development of disease activities in RA patients by regulating the intestinal microbiome and immune microenvironment, which is a safe and effective treatment method.

Key words: rheumatoid arthritis, intestinal microbiome, immune microenvironment