Rheumatoid arthritis (RA) is a condition characterized by systemic inflammation. People suffering from RA experience pain, swelling, stiffness, and loss of function in their fingers, wrists, and/or other joints in the body. RA is an autoimmune disease, meaning that it is a result of the body’s own immune system mistakenly attacking its own tissues. In this case, the tissues being attacked include membranes that line the joints.
The cause of rheumatoid arthritis is not currently known. It could be genetic, or it could be a result of environmental or behavioral factors such as smoking, diet, and stress. All of these factors influence the activity of the immune system. Additionally, the immune system is heavily influenced by the microbiome, which is the collection of bacteria that live inside the human body. The microbiome includes both helpful and harmful bacteria, many of which live within the digestive tract.
Many studies have been conducted to discover the cause of rheumatoid arthritis. Some believe that the microbiome is a factor that can lead to the development of RA. One such study was conducted to see if the presence of a specific gut bacteria is linked to RA. The study was conducted by Dr. Dan Littman of NYU School of Medicine and a team of researchers. The results of the study were reported by Carol Torgan in her article “Gut Microbes Linked to Rheumatoid Arthritis” in the National Institutes of Health. The results of the study were published in eLife on November 5, 2013.
The researchers examined DNA in 114 stool samples from people suffering from rheumatoid or psoriatic arthritis and healthy individuals. The data showed that 75% of the people with new-onset, untreated rheumatoid arthritis had traces of Prevotella copri in the intestinal microbiome. The same bacteria was only found in 12% of people with treated RA, 38% of people with psoriatic arthritis, and 21% of healthy individuals. The report states “The researchers performed more complete DNA sequencing on a subset of samples and identified unique Prevotella genes that correlated with rheumatoid arthritis.”
Furthermore, Dr. Littman stated “At this stage, however, we cannot conclude that there is a causal link between the abundance of P. copri and the onset of rheumatoid arthritis. We are developing new tools that will hopefully allow us to ask if this is indeed the case.”