Oral Microbiome Different for Patients with Rheumatoid Arthritis

Patients with rheumatoid arthritis (RA) and those who are at high risk for the disease had a distinctly different oral microbiome compared to healthy controls, according to a study.

“It has been suggested that RA may originate at the oral mucosa. Our aim was to assess the oral microbiome and the periodontal condition in patients with early rheumatoid arthritis (ERA) and individuals at risk of RA,” the researchers explained.

Participants were stratified into three groups: patients with ERA, at-risk individuals with arthralgia and autoantibodies, and healthy controls; all three groups had 50 participants each. They were all examined by a dentist and scored for bleeding on probing (BOP), pocket probing depth (PPD), and periodontal inflamed surface area (PISA), and 16s rDNA amplicon sequencing was used to evaluate the microbial composition of subgingival dental plaque, saliva, and tongue coating of each patient.

There were no differences among the groups in terms of BOP (P=0.70), PPD (P=0.30), and PISA (P=0.56).

However, the microbial composition differed when looking at saliva (F=2.08, P<0.001) and tongue coating (F=2.04, P=0.008)—but not plaque (P=0.51), noted the authors.

The ERA and at-risk groups did not differ in terms of saliva (F=1.12, P=0.28) or tongue coating (F=0.834, P=0.59). ERA patients had higher relative abundance of Prevotella (saliva) and Veillonella (saliva and tongue coating) than healthy controls.

The study was published in Arthritis & Rheumatology.

“The results show similarities in the oral microbiome between ERA patients and at‐risk individuals, both presenting with increased relative abundance of potentially pro‐inflammatory species compared to healthy controls, suggesting a possible association between the oral microbiome and RA onset,” the study authors wrote in their conclusion.