Variations in oral microbiome profiles in rheumatoid arthritis and osteoarthritis with potential biomarkers for arthritis screening Original paper
Researched by:
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Kimberly Eyer
ID
Kimberly Eyer
Kimberly Eyer, a Registered Nurse with 30 years of nursing experience across diverse settings, including Home Health, ICU, Operating Room Nursing, and Research. Her roles have encompassed Operating Room Nurse, RN First Assistant, and Acting Director of a Same Day Surgery Center. Her specialty areas include Adult Cardiac Surgery, Congenital Cardiac Surgery, Vascular Surgery, and Neurosurgery.
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Rheumatoid Arthritis
Rheumatoid Arthritis
OverviewRheumatoid arthritis (RA) is a systemic autoimmune disease marked by chronic joint inflammation, synovitis, and bone erosion, driven by Treg/Th17 imbalance, excessive IL-17, TNF-α, and IL-1 production, and macrophage activation. Emerging evidence links microbial dysbiosis and heavy metal exposure to RA, [1][2] with gut microbiota influencing autoimmune activation via Toll-like receptor (TLR) signaling, inflammasome activation, […]
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Kimberly Eyer
Researched by:
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Kimberly Eyer
ID
Kimberly Eyer
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Kimberly Eyer
What was studied?
This study investigated the differences in oral microbiome composition among patients with rheumatoid arthritis (RA), osteoarthritis (OA), and healthy controls to identify potential oral microbial biomarkers for arthritis screening. Using 16S rRNA gene sequencing of saliva samples, the authors profiled the oral microbiota of 110 RA patients, 67 OA patients, and 155 healthy controls. They aimed to differentiate RA from OA through taxonomic and functional microbial differences and to evaluate the predictive power of selected taxa as diagnostic biomarkers.
Who was studied?
Saliva samples were obtained from 332 individuals: 110 diagnosed with RA, 67 with OA, and 155 healthy subjects. All RA participants met the 2010 ACR/EULAR criteria, and OA patients fulfilled the 1995 revised ACR classification criteria. Subjects with active periodontal disease or recent antibiotic/probiotic use were excluded to minimize confounding effects on microbial composition. Samples were standardized in collection conditions and processed using high-throughput sequencing for comparative microbial analysis.
What were the most important findings?
The study found that oral microbial diversity was elevated in both RA and OA compared to healthy controls. Specific microbial signatures differed between the two diseases. RA patients had greater relative abundances of Neisseria, Haemophilus parainfluenzae, Prevotella, Veillonella dispar, and Actinobacillus. In contrast, OA patients exhibited enrichment of Streptococcus, Actinomyces, Rothia, and Granulicatella. Functional predictions revealed metabolic pathway differences—most notably in lipopolysaccharide biosynthesis and glycolysis/gluconeogenesis—between RA and OA microbiota. A classifier based on eight distinct operational taxonomic units (OTUs) yielded an AUC of 0.8756 for differentiating RA from OA, demonstrating potential for non-invasive microbial diagnostics. Many of the identified taxa (e.g., Prevotella, Haemophilus, Veillonella) are Gram-negative anaerobes linked to mucosal inflammation and may influence systemic immune activation.
| Feature | Rheumatoid Arthritis (RA) | Osteoarthritis (OA) | Key Implications |
|---|---|---|---|
| Enriched Genera | Prevotella, Veillonella dispar, Neisseria, Haemophilus | Streptococcus, Actinomyces, Rothia, Granulicatella | Potential microbial biomarkers for disease discrimination |
| Functional Pathways | Increased LPS biosynthesis, glycolysis/gluconeogenesis | Distinct from RA, lower LPS biosynthesis | Functional shifts reflect inflammatory vs. degenerative mechanisms |
| Microbial Diversity | Elevated vs. healthy controls | Also elevated | Suggests broader dysbiosis across arthritis subtypes |
| AUC for Biomarker Model | 0.8756 | N/A | High predictive value for non-invasive screening |
| Major Microbial Associations (MMAs) | Prevotella, Haemophilus, Veillonella | Streptococcus, Rothia | Useful for microbiome-targeted diagnostics or interventions |
What are the greatest implications of this study?
This study highlights the value of the oral microbiome as a diagnostic reservoir for systemic autoimmune and inflammatory joint diseases. The differentiation between RA and OA via salivary microbiota offers a non-invasive screening avenue that could complement or improve upon existing serological markers. From a microbiome signature perspective, Prevotella, Veillonella dispar, and Haemophilus parainfluenzae represent key Major Microbial Associations (MMAs) in RA, whereas Streptococcus and Rothia were associated with OA. Functional distinctions in microbial metabolic pathways may also reflect pathophysiological differences, such as enhanced inflammatory signaling in RA. The findings support integrating oral microbiota profiles into arthritis diagnostics and reinforce the systemic relevance of mucosal microbiomes in chronic disease pathology.