The intestinal microbiome, a key to predicting rheumatoid arthritis?

Can we anticipate rheumatoid arthritis by observing the evolution of the intestinal microbiome? This is what a new study led by the University of Leeds (United Kingdom) would suggest: by identifying specific changes in the microbiome of people at risk, researchers reveal potential mechanisms for triggering the disease.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints, making them painful, stiff and swollen. Affecting more than 18 million people worldwide, this pathology causes daily suffering and impairs quality of life. If current treatments aim to limit the symptoms, it remains essential to better understand its causes and its first manifestations for earlier treatment.

The gut microbiome as a warning signal

As part of their work, published in the Annals of the Rheumatic Diseasesresearchers analyzed intestinal samples from 124 individuals with specific antibodies associated with the risk of developing RA (called anti-CCP), and musculoskeletal symptoms without joint swelling. Of these participants, followed over a period of 15 months, 30 ultimately developed RA.

The results show a notable difference in the presence of certain bacteria, notably the family of Prevotellaceaein individuals who developed the disease. Researchers observed marked instability in the microbiome of people progressing to RA, which intensified approximately ten months before the onset of clinical symptoms. This upheaval of the microbiome could thus constitute a “alert signal” before the visible manifestation of the disease, according to a press release.

Better identify people at risk of rheumatoid arthritis

Bacteria Prevotellaceaealthough present in greater quantities in certain individuals at risk, do not have an exclusive role in the onset of RA. Rather, variations in this bacterial family appear to correspond to changes in amino acid metabolism within the microbiome. Thus, some strains are enriched while others decrease, depending on each person’s risk profile and the time remaining before disease progression.

These findings highlight the importance of microbiome dynamics in the transition from at-risk state to RA onset. This bacterial evolution could explain contradictions in previous research on the abundance of Prevotellaceae. From now on, the intestinal microbiome could become a diagnostic and prevention tool, making it possible to identify individuals most likely to develop the disease.