Rheumatoid arthritis (RA) is a chronic autoimmune condition and while the exact cause of RA remains elusive, researchers have discovered a potential link between gut bacteria and the development of this debilitating disease. Emerging evidence suggests that imbalances in the gut microbiome may play a role in triggering and exacerbating RA symptoms.

Here is what we know about the connection between gut bacteria and rheumatoid arthritis:

The Gut Microbiome: The gut microbiome comprises trillions of microorganisms, including bacteria, viruses, and fungi, residing in the gastrointestinal tract. This complex ecosystem plays a crucial role in maintaining immune function, digestion, and overall health. Studies have shown that alterations in the composition and diversity of the gut microbiota may contribute to the development of autoimmune conditions like rheumatoid arthritis.

Leaky Gut and Immune Dysregulation: One proposed mechanism linking gut bacteria and rheumatoid arthritis is increased intestinal permeability, commonly known as “leaky gut.” When the intestinal barrier becomes compromised, it allows harmful bacteria and their byproducts to enter the bloodstream. This triggers an immune response, leading to chronic inflammation and potentially setting the stage for autoimmune diseases like RA. Evidence suggests that the gut microbiota can influence the integrity of the intestinal barrier, potentially contributing to the development of RA.

Microbial Dysbiosis and Immune Activation: Research indicates that individuals with rheumatoid arthritis tend to have an altered gut microbiota composition compared to healthy individuals. The imbalance, known as microbial dysbiosis, involves a decrease in beneficial bacteria and an increase in potentially harmful bacteria. Dysbiosis can disrupt the delicate immune balance in the gut, leading to the activation of immune cells that may mistakenly target joint tissues, triggering inflammation and joint damage.

Role of Molecular Mimicry: Molecular mimicry is another potential mechanism linking gut bacteria and rheumatoid arthritis. Some bacterial species in the gut produce proteins that resemble proteins found in the joints. When the immune system mounts an attack against these bacterial proteins, it may also mistakenly attack similar proteins in the joints, leading to chronic inflammation and joint damage. This phenomenon highlights the intricate relationship between gut bacteria and the immune system’s response in RA.

Researchers are still studying the gut microbiota’s role in rheumatoid arthritis, but the following interventions targeting the microbiota show promising results for treating and potentially preventing the condition:

Probiotics and Prebiotics: Probiotics are beneficial bacteria that can restore gut microbial balance, while prebiotics act as fuel for the growth of beneficial bacteria. A randomized controlled trial published in Joint Bone Spine demonstrated that a specific probiotic strain (Lactobacillus casei) reduced disease activity and improved clinical outcomes in rheumatoid arthritis patients.

Dietary Modifications: Certain dietary patterns, such as the Mediterranean diet and high-fiber diets, have been associated with a more diverse and beneficial gut microbial profile. Incorporating more fruits, vegetables, whole grains, and fermented foods into the diet can positively influence the gut microbiota and potentially aid in RA management.

Sources:

• Scher, J. U., Sczesnak, A., Longman, R. S., Segata, N., Ubeda, C., Bielski, C.,… & Abramson, S. B. (2021). Expansion of intestinal Prevotella copri correlates with enhanced susceptibility to arthritis. eLife, 2, e01202.
• Zhang, X., et al. (2021). Gut microbiota alterations in patients with rheumatoid arthritis: A systematic review. Journal of Clinical Rheumatology, 27(1), 19-25.