Biology of tongue coating in different disease stages of RA and its value in disease progression

Abstract

Objective: To assess and compare the composition of tongue coating microbiota among patients at different stages of rheumatoid arthritis (RA).

Methods: A total of 47 patients diagnosed with RA, as per the American College of Rheumatology criteria, and 10 healthy individuals were enrolled in this study. The RA patients were stratified considering their Disease Activity Score 28 (DAS28), a composite measure based on the 28 tender and swollen joint count and erythrocyte sedimentation rate (ESR). The study population was further categorized into active phase group (LMH group) and inactive phase group (RE group) according to their DAS28 values. DNA extraction was extracted from tongue coating samples. Subsequently, the V3-V4 16S rDNA region was selectively amplified and sequenced through high-throughput 16S rDNA analysis. The resulting data were then utilized to ascertain the microbial contents.

Results: Significant variations were observed in the tongue coating microbiota of patients with RA during active and inactive phases, in comparison to healthy individuals (p < 0.05). At the genus level, the presence of Prevotellan, Veillonella, Rothia, and Neisseria in RA patients was notably more evident than in the healthy control (HC) group. These disparities find support in existing research on gut and oral microbiota. During the active phase of RA, the relative abundance of Veillonella, Rothia, and Neisseria in the tongue coating microbiota of patients was significantly higher than in those with inactive RA. These findings underscore the need for further and in-depth research on the potential impact of these microorganisms on the progression of RA disease.

Conclusion: The results substantiate the hypothesis that tongue coating microbes actively contribute to the progression of RA.

Keywords: 16S rRNA; Disease activity; Rheumatoid arthritis; Tongue coating microbiota.