Study Probes Gut Health as Missing Link Between Diet and Rheumatoid Arthritis Activity
A new Arizona-based research project aims to clarify why many people with rheumatoid arthritis (RA) struggle to reach sustained remission by testing whether diet influences disease activity indirectly through gut health and inflammation, according to an article published in JMIR Research Protocols.
RA, an autoimmune disease affecting about 1.3 million Americans, causes episodic but persistent inflammation that can lead to chronic pain, fatigue, disability, and irreversible joint damage. Even with modern medications designed to bring patients to remission, many do not achieve that goal, leaving them vulnerable to complications such as hypertension, depression, and cardiovascular disease, along with major financial and work-related burdens.
The funded study, launched in February 2024, is built on an evidence-based Biopsychosocial Model of Disease Experience in RA that links biological, psychological, and social drivers of disease activity. Investigators hypothesize that common factors such as stress, socioeconomic status, obesity, smoking, medication use, age, gender, and ethnicity interact with diet and gastrointestinal (GI) health to shape inflammation and symptoms. “This study uses a cross-sectional design to describe associations between background factors and diet quality and to test 2 a priori hypotheses regarding the relationship between diet quality, gut microbiome diversity, and GI inflammation on disease activity in RA,” explained Maureen McGarrity-Yoder, RN, PhD, College of Nursing, Northern Arizona University, Flagstaff, United States, and coauthors.
Patient interest in diet is high, but prior research has produced mixed results, in part because diet is often self-reported and because studies rarely incorporate biological measures that could explain how food affects inflammation. This study focuses on the gut microbiome and GI inflammation as potential bridge mechanisms. People with RA are more likely to have gut dysbiosis, and certain bacterial patterns have been linked to mucosal inflammation and may play a role in RA development. The study will also measure fecal calprotectin, a marker of intestinal inflammation, alongside blood-based inflammatory markers used in RA care.
The researchers plan to recruit at least 96 adults aged 18 and over with RA across Arizona through rheumatology clinics, universities, community health sites, and the Arthritis Foundation with materials available in English and Spanish and dedicated outreach days for Spanish-speaking participants. Participants complete surveys and dietary assessments, undergo joint exams for Disease Activity Score-28 (DAS-28), provide blood samples for ESR and high-sensitivity CRP, and submit stool samples for 16S rRNA sequencing to quantify microbiome composition and diversity.
Reference
McGarrity-Yoder M, Cope EK, Wayment HA, Rodriguez-Pla A, Crane TE. Biopsychosocial determinants, diet quality, gastrointestinal health, and disease activity in adults with rheumatoid arthritis: cross-sectional descriptive study. JMIR Res Protoc. 2026;15:e79889. doi:10.2196/79889
