Rheumatoid Arthritis Starts in the Mouth?
The oral microbiome, RA and Periodontal Disease

Did you know there is a mouth-body connection? Research has demonstrated a link between periodontal (gum) disease and rheumatoid arthritis (RA), an autoimmune disease. Although oral health and joint pain may seem unrelated, what we are learning about the oral microbiome would tell us otherwise.`

Periodontal disease and the oral microbiome

The oral microbiome is the community of microbes that live in the human mouth. It turns out that we have a symbiotic relationship with these microbes. Thus, they create their own carefully balanced ecosystems in certain parts of our bodies. When in balance, these ecosystems promote our health. However, an unbalanced microbiome can lead to oral and even systemic diseases. See our post on Oral Microbiome Basics for Autoimmune Patients.

New research has found that the cause of periodontal disease may be a disruption of the oral microbiome. Periodontal disease, also known as gum disease, is a common condition that usually develops in a patient’s 30s or 40s. Major symptoms include bad breath, swollen gums, and loose teeth. Originally, dentists and periodontists thought that bad bacteria in dental plaque caused periodontal disease. But as we learn more about the oral microbiome, our initial understanding of periodontal disease begins to change.

We are just beginning to learn about the composition of this complex community, and how it might relate to autoimmunity. What we do know is that the oral microbiome connects to microbes all over our body. These microbes can go create their own communities in areas like the gut and lungs. Each microbiome has different microbe composition, but are all distinctly related to each other. Immune responses to unbalanced microbiomes may be related to autoimmune disease.

Rheumatoid arthritis and periodontal disease

Rheumatoid arthritis (RA) is an autoimmune disease that affects about 1.5 million people in the United States. It affects the joints, particularly the wrists and fingers, resulting in swelling, stiffness and pain. Rheumatoid arthritis differs from osteoarthritis in several ways. First, it’s an autoimmune disease, where immune cells mistakenly attack their own (self) cells and tissues. Consequently, RA may include symptoms, such as fevers and fatigue, not seen in wear-and-tear arthritis. Also, RA may attack tissues other than joints, most seriously heart valves. Symptom-wise, RA is symmetrical (if you have it in one hand, you are likely to have it in the other). On the other hand, osteoarthritis reflects asymmetrical use and handedness.

The microbiome may prove to be an important factor among the multiple causes of rheumatoid arthritis. Researchers have found that high exposure to bacterial antigens may trigger RA. Such bacterial antigens can enter the body through the mouth, gut and lungs. The key point here is that release of bacterial antigens is especially high in areas with periodontal lesions.

What’s the microbiome connection?

So what do periodontal disease and RA have in common? And how does that relate to the oral microbiome?

Recent studies have discovered that the microbiome may be a “trigger,” an “environmental factor that can influence autoimmune disease manifestation.” An examination of patients with new-onset RA found they had a much higher prevalence of gum disease than the general population. This was despite the fact that they were mostly young and non-smokers. But which way does the arrow of causality point? Gum disease could be a side effect of RA, or it may be a precursor or even a causal factor. If it is a precursor, it may serve as an early warning biomarker. Perhaps the advent of periodontal disease could tell us in advance whether or not an individual may develop rheumatoid arthritis.


Research to determine the exact relationship between the oral microbiome, periodontal disease, and rheumatoid arthritis is ongoing. If periodontal disease is a precursor to rheumatoid arthritis, we may be able to intervene earlier. We could treat the periodontal disease, treat the RA earlier, or even prevent autoimmune damage entirely.

Does this mean we will be able to treat and even prevent rheumatoid arthritis? Is the oral microbiome a new vital resource for determining and promoting total body health? Only time will tell.

Have you, or someone you know, been diagnosed with both advanced periodontal disease and rheumatoid arthritis? Tell us your story!

1 comment

  1. Periodontitis is a progressive disease of the periodontium with a complex, polymicrobial etiology. Recent Next-Generation Sequencing (NGS) studies of the microbial diversity associated with periodontitis have revealed strong, community-level differences in bacterial assemblages associated with healthy or diseased periodontal sites. In this study, we used NGS approaches to characterize changes in periodontal pocket bacterial diversity after standard periodontal treatment. visit https://thisoldtooth.com/

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