Microecology of tongue coating flora in patients with rheumatoid arthritis

Objective To investigate the relationship between disease progression and microecology of tongue coating flora in patients with rheumatoid arthritis (RA). Methods A total of 30 tongue coating flora swabs were collected from 20 RA patients, including 10 in the active stage (OP group) and 10 in the remission stage (OR group), and 10 healthy individuals (OHC group).The total DNA extracted by rapid oral swab genomic DNA extraction kit was amplified with 16S rRNA and sequenced with high throughput Illumina MiSeq. The results were analyzed by microecology. Results There was no statistical difference in the diversity of 3 groups of samples (P>0.05). All the 3 groups of samples had their own unique genera, including 7 genera in OP group, 4 genera in OR group, and 10 genera in OHC group; The samples from 3 groups had the same composition of dominant flora, but obvious difference was seen in the composition of flora, mainly in p_Firmicutes, p_Actinobacteria, p_Episilonbacteraeota, p_Proteobacteria, g_Neisseria, g_Actinomycetes, g_Campylobacter, and g_Porphyromonas (all P < 0.05). Through PCA analysis and hierarchical cluster analysis, OP group and OHC group can gather together well with significant differences. Conclusion There are differences between the flora of tongue coating in RA patients and healthy individuals. The abundances of Actinomycetes and Campylobacter are increased, while those of Neisseria and Porphyromonas are decreased.