Rheumatoid arthritis (RA) is a systemic autoimmune disease that affects more than just the joints, with emerging evidence indicating abnormalities in the gut microbiome of RA patients. Research suggests that gut microorganisms may influence both the development of RA and patients’ responses to treatments, highlighting the personalized nature of the microbiome and its potential role in therapy effectiveness and side effects.
It is not uncommon for patients with autoimmune diseases to have some sort of abnormality in the gut, according to Renuka Nayak, MD, PhD, Assistant Professor, University of California, San Francisco. Literature even suggests that the microorganisms that live in the gastrointestinal (GI) tract may play a role in the development of the disease.
During the Tuesday, October 28, session Gastrointestinal Manifestations of Connective Tissue Diseases: Diagnosis, Treatment, and Emerging Research, Dr. Nayak will join a multidisciplinary panel to review clinical and translational aspects of GI tract involvement in autoimmune rheumatic diseases. The session will take place from 8:30–10 a.m. in Room W375C of McCormick Place.
Christopher Rooney, MD, PhD, MRCP, Clinical Lecturer in Medical Microbiology, University of Leeds, United Kingdom, will discuss the impact of the gut microbiome in individuals at risk of RA. Elizabeth Volkmann, MD, MS, Associate Professor, Division of Rheumatology, University of California, Los Angeles, will explore how nutrition affects the gut microbiome, highlighting dietary modifications that may ameliorate GI systems in rheumatic diseases.
“My team’s research focuses on how those microbes may also play a role in treatment response,” Dr. Nayak said. “Our lab is looking at how gut microorganisms metabolize RA drugs, if they are contributing to disease, and how they may act on the microbiome to reduce inflammation.”
Because an individual’s microbiome is very personalized, it may account for some of the variations in clinical response observed with different therapies. Ultimately understanding and paying attention to the community of GI microorganisms may allow physicians to better treat patients.
Complex Interaction
Dr. Nayak said there are three different scenarios for the mechanism at work in the gut of RA patients.
“In the first scenario, the microbes are contributing to disease, so in that sense the treatment might actually be working through its effects on the microbiome,” she said. In that scenario, treatment could target the microbes without having to immunosuppress the patient.
In a second scenario, treatment (e.g., methotrexate) may act on the microbes to cause unwanted side effects, leading patients to discontinue the drug. “If we could determine the microbes are being affected by the drug, we could replenish those microbes to avoid side effects,” Dr. Nayak said.
Scenario number three is that the microbes do not harm the patient, but they do prevent optimal uptake of the medication. “In that case, the aim would be to perhaps design a therapeutic regimen that prevents the microbes from breaking down the drug,” Dr. Nayak explained.
Many patients suffer from side effects, inadequate responses to therapies, or from flares, which frequently happen even to patients who are generally satisfied with their medication. Although the field’s emphasis historically has rightfully been on the immune system, gut microbes also play a role.
“There may be a real interaction between the microorganisms and the immune system that researchers can manipulate to improve patients’ quality of life,” Dr. Nayak said.
Diet as Therapy
GI health is an issue that is top of mind for many RA patients. They want to know if there are diet and lifestyle changes that can help them manage their disease, Dr. Nayak said.
“When patients come into the clinic asking about dietary interventions, it is very hard to give personalized advice because everybody’s microbiome is different,” she noted. “We need to be thinking about personalized medicine and eventually, personalized nutrition.”
Still, when it comes to making recommendations to RA patients, general, universally applicable dietary advice is relevant for the sake of the overall health and for the microbiome: Avoid highly processed food, and excessive sugar and fat. Consume mostly plant-based, high-fiber, and nutrient-dense foods.
On-demand access to recorded presentations will be available to registered participants of ACR Convergence following the annual meeting through October 31, 2026.
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