Studies suggest rheumatoid arthritis connected to gut microbiome


Dear Doctor: I understand that there may be a connection between rheumatoid arthritis and your gut microbiome. I’m newly diagnosed with RA, so I’m very interested in learning more about that.

Dear Reader: Arthritis refers to a collection of diseases in which inflammation in the joints causes stiffness, swelling, pain and sometimes physical damage. There are more than 100 different types of arthritis and related conditions, and they affect people of all ages. In the case of rheumatoid arthritis, also referred to as RA, the symptoms arise because the immune system has gone awry. Instead of concentrating on protecting the body from foreign invaders, it begins to attack the body’s own tissues.

The onset of RA is typically marked by persistent tenderness or pain in the joints of the wrists and in the hands and feet. As the disease progresses, the joints may become red and swollen. This is often accompanied by a period of generalized stiffness upon arising in the morning. Fatigue, which can become severe, and a low-grade fever may also be present. It’s common for the symptoms of RA to ebb and peak. The periods of time when symptoms are severe are known as flares. These can last anywhere from several weeks to several months. Treatment, which is tailored to each person’s specific symptoms, focuses on medication, along with physical and occupational therapy. When RA results in joint damage or deformity, patients may be offered a range of surgical options.

Although the causes of RA are not yet understood, research continues to suggest that the disease is linked to the gut microbiome. That’s the collection of billions of microbes that live in the intestines. They play such a crucial role in our health and well-being that the gut microbiome is often thought of as another organ.

Elizabeth Ko, MD and Eve Glazier, MD

Studies into the gut microbiome have established that helping to regulate the immune system is one of its important functions. That led researchers to explore the ways in which imbalances or abnormalities in the microbial colonies in the gut could adversely affect immune function. A study published in 2013 found unusually high concentrations of a specific bacterium in stool samples taken from people newly diagnosed with RA. A subsequent mouse study found that the bacterium plays a role in setting off inflammation. New research has found evidence that so-called leaky gut, a digestive disorder that lets bacteria and toxins “leak” through the intestinal wall, may also play a role.

The results of a mouse study published last spring found a strong connection between joint inflammation and damage to the lining of the gut. Although, at this time, the evidence falls short of proving cause and effect between the gut and RA, it continues to offer a promising path. This includes using the gut itself as a therapeutic target. New research is focusing on how to restore the integrity of the gut lining in order to prevent the leakage of bacteria and toxins, as well as exploring ways to restore a healthful balance to the colonies of microbes living there. It’s a promising avenue of inquiry that may someday lead to new treatment options for RA.

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