Differences in the Oral Microbiome in Patients With Early Rheumatoid Arthritis and Individuals at Risk of Rheumatoid Arthritis Compared to Healthy IndividualsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study tested whether the oral microbiome and periodontal condition differ in early rheumatoid arthritis and in people at risk of the disease. The idea being probed is that rheumatoid arthritis may originate at mucosal surfaces such as the mouth. Subgingival plaque, saliva, and tongue coating were profiled by 16S ribosomal DNA amplicon sequencing. Community differences between groups were tested with permutational multivariate analysis of variance.
Who was studied?
The cohort was 150 adults in the Netherlands, 50 per group. Group one had early rheumatoid arthritis diagnosed within the prior year, group two had arthralgia plus rheumatoid arthritis autoantibodies, and group three were healthy controls matched by sex and age. Mean age was about 51 to 52 years, and roughly three quarters were female in each group. A single trained dentist performed all periodontal exams and sampling.
What were the most important findings?
Periodontal measures did not differ across groups. Bleeding on probing, pocket probing depth, and periodontal inflamed surface area gave p values of 0.70, 0.30, and 0.57. Saliva and tongue coating composition differed significantly by group (saliva F = 2.08, p = 0.0002; tongue F = 2.04, p = 0.008), but subgingival plaque did not (F = 0.948, p = 0.51). Early rheumatoid arthritis and at-risk groups did not differ from each other. Prevotella in saliva and Veillonella in saliva and tongue coating were more abundant in early rheumatoid arthritis and at-risk individuals than in controls. Porphyromonas gingivalis was not discriminative.
What are the greatest implications of this study?
Early rheumatoid arthritis and at-risk individuals shared an oral profile enriched for potentially proinflammatory species, hinting at a link between the oral microbiome and disease onset. The overlap between diagnosed and at-risk groups is notable. The absence of plaque and periodontal differences argues against periodontitis-specific pathogens as the trigger. Because the data are cross-sectional and most patients were already on treatment, a reverse pathway where inflammation favors these microbes cannot be ruled out.