Bacterium behind gum infection may increase rheumatoid arthritis risk

Researchers at the University of Louisville's School of Dentistry have identified the bacteria responsible for gum disease linked to early onset of rheumatoid arthritis.

According to the study, the bacterium produces an enzyme that reacts with certain protein in the body, which often leads to chronic inflammation responsible for bone and cartilage destruction within the joints.

The researchers have based their findings on the results of a clinical trial that showed that the bacteria, P. gingivalis, produce a unique enzyme called peptidylarginine deiminanse (PAD). The enzyme in turn enhances a collagen-induced arthritis (CIA), similar to rheumatoid arthritis. PAD reacts with the residues of certain proteins and converts them into citrulline.

The body considers these citrullinated proteins intruders and leads an immune attack to resist their presence, resulting in chronic inflammation.

On the same breath, the researchers also tested one more oral bacterium, Prevotella intermedia, which did not produce PAD or trigger the subsequent consequences.

The researchers are hopeful their study will help evolve a new line of treatment for rheumatoid arthritis patients.

However, the researchers claim further interventions are required before the findings are put into practice.

"Taken together, our results suggest that bacterial PAD may constitute the mechanistic link between P. gingivalis periodontal infection and rheumatoid arthritis, but this ground-breaking conclusion will need to be verified with further research," Dr. Jan Potempa, from the University of Louisville School of Dentistry Oral Health and Systemic Diseases and the lead author of the study, said in a press release.

Previous studies have revealed a correlation between periodontal disease and rheumatoid arthritis. To prevent gum infections, health experts suggest brushing twice a day, flossing and maintaining a balanced diet.