While organs such as the lungs and skin are important in the pathogenesis of many diseases, it’s becoming more and more evident that the saying “All disease begins in the gut” is not far from the truth. It seems that most, if not all, chronic diseases of civilization are characterized by poor nutrition and gut health and that treating the symptoms locally (e.g., topical creams for acne) doesn’t address the underlying causes of the disease. The latest in a long list of health disorders associated with abnormal gut flora is rheumatoid arthritis, a common systemic autoimmune disease that affects 1.3 million americans.
A newly published study found that the onset of rheumatoid arthritis could be partly mediated by specific intestinal bacteria. Researchers found that patients with newly diagnosed rheumatoid arthritis had more of a species of bacteria called Prevotella copri in their guts compared to healthy individuals or patients with chronic, treated rheumatoid arthritis. DNA analysis also showed that an abundance of P. copri was associated with lower levels of beneficial bacteria.
While it’s to early to say if there’s a causal link between levels of P. copri and the risk of developing rheumatoid arthritis, studies in sterile mice have shown that colonization with bacteria such a P. copri increases gut inflammation and sensitivity to chemically induced colitis.
Patients who’ve received treatment for Rheumatoid arthritis carry smaller populations of P. copri, which could indicate that the treatment alters the balance of bacteria living in the GI tract. However, it could also mean that bacteria such as P. copri thrive in an inflammatory environment.
It’s likely that an inflammatory microbiota with an overgrowth of certain species of bacteria such as Prevotella copri and lower levels of beneficial bacteria supports the systemic immune response required for joint inflammation in conditions such as rheumatoid arthritis. A healthy gut flora significantly lowers the risk of developing autoimmune disease, but it remains to be seen whether dietary changes, probiotics and prebiotics can improve symptoms of chronic rheumatoid arthritis.