Comparative Study Of Gut Microbiota In Patients With Rheumatoid Arthritis And In Healthy Controls

Objective: The 16 SrDNA gene sequencing method was used to compare the intestinalflora of RA patients with healthy people.The structure and diversity of intestinal flora in RA patients will be initially explored,which provid a theoretical basis for RA diagnosis and treatment.Methods: In this study,the fecal samples from 15 newly diagnosed rheumatoid arthritis patients and 10 healthy controls were immediately concentrated with dry ice to the laboratory under low temperature conditions.The total bacterial DNA in the stool samples was extracted using a gene extraction kit,amplified by PCR,and sequenced by HiSeq.The results were analyzed by Operational taxonomic units(OTUs)clustering and species classification analysis,species annotation,?-diversity analysis,and ?-diversity analysis.Finally,the difference in intestinal flora between RA patients and healthy controls was compared.Results: 1.There were no statistically significant differences in gender,age,and BMI between rheumatoid arthritis patients and healthy controls(P>0.05).2.A total of 3851 OTUs were obtained by OTU cluster analysis.At the level of phylum,the abundance of Oxyphotobacteria and Fusobacteria increased in rheumatoid arthritis group(P<0.05).The abundance of Proteobacteria,Chloroflexi,Acidobacteria,and Fibrobacteres was decreased(P<0.05).At the genus level,the abundance of Faecalibacterium,Bacteroides,and Erysipelatoclostridium increased in the rheumatoid arthritis group,but decreased in unidentified_Lachnospiraceae,Megasphaera,and Macromonas(P<0.05).At the species level,the abundance of Erysipelatoclostridium_ramosum was significantly increased in the rheumatoid arthritis group(P<0.01),while the abundance of Bacteroides_plebeius and Megasphaera_elsdenii was significantly reduced(P<0.01).3.?-diversity analysis indicated that the sequencing depth of this study was reasonable,and the intestinal flora richness and diversity of rheumatoid arthritis patients were lower than those of healthy controls.4.In the ?-diversity analysis,the PCoA analysis indicated that the intestinal flora of the rheumatoid arthritis group was significantly different from the healthy control group(P<0.05).The UPGMA clustering map suggests that the phylogenetic relationship between the two groups is far away,and the community structure is significantly different.The samples in the same group were clustered together,and the flora structure was similar.5.LEfSe analysis found that there were 16 biomarkers,9 of them were enriched in rheumatoid arthritis,and 7 of them were enriched in healthy controls,The three most important biomarkers belong to Clostridium,Clostridium,Ruminococcaceae(P<0.05).Conclusion: Dysbiosis occured in patients with rheumatoid arthritis.Compared with healthy controls,the richness and diversity of intestinal flora decreased in RA,In the intestinal of patients with rheumatoid arthritis,the abundance of Clostridia,Clostridiales,and Ruminococcaceae was significantly increased,and the abundance of Proteobacteria,Gammaproteobacteria,Selenomonadales was significantly reduced.