Treatment for Rheumatoid Arthritis Associated With Alterations in the Gastrointestinal Microbiota

Area of Science:

• Microbiome research
• Gastroenterology
• Rheumatology

Background:

• Rheumatoid arthritis (RA) is increasingly associated with intestinal dysbiosis.
• Understanding the gut microbiome's role in RA pathogenesis and treatment response is crucial.

Purpose of the Study:

• To prospectively evaluate changes in intestinal microbial composition in RA patients starting methotrexate (MTX) or tumor necrosis factor inhibitor (TNFi) therapy.
• To assess the relationship between microbial changes, disease activity, and treatment response.

Main Methods:

• A prospective pilot study involving 50 RA patients initiating MTX or TNFi therapy.
• Stool samples were collected at baseline and 3 months for microbiota analysis using the GA-map Dysbiosis Index Score (DIS).
• Fecal Prevotella copri (P. copri) abundance was quantified, and changes were correlated with disease activity scores.

Main Results:

• Baseline dysbiosis was observed in 66% of participants, more prevalent in those with RA >2 years.
• After 3 months, 28% showed improved DIS, with TNFi users demonstrating greater improvement than MTX users (P=0.031).
• Decreased P. copri abundance correlated with improved disease activity (r_s=0.30, P=0.036).

Conclusions:

• Dysbiosis is a characteristic feature of rheumatoid arthritis.
• RA therapies, specifically TNFi, may differentially modulate the gut microbiota.
• The association between P. copri and treatment response warrants further investigation.