Kimberly Eyer
Self-Balance of Intestinal Flora in Spouses of Patients With Rheumatoid Arthritis Original paper
Kimberly Eyer
What was studied?
Rheumatoid ArthritisThis study examined the composition of intestinal microbiota in individuals with rheumatoid arthritis (RA), their cohabiting spouses, and healthy controls to evaluate the relative contributions of environmental versus genetic factors to RA-associated dysbiosis. Utilizing 16S rRNA gene sequencing, the researchers compared microbial diversity and taxonomic profiles across the three groups and explored associations with clinical parameters to assess whether shared environments shape microbiota similarly in spouses of RA patients.
Who was studied?
The study cohort consisted of 30 RA patients, 30 of their cohabiting spouses (SPs), and 20 healthy control individuals (HCs). All RA participants fulfilled the 2010 ACR diagnostic criteria and tested positive for anti-cyclic citrullinated peptide (anti-CCP) antibodies. To control for environmental influences, RA-SP pairs were required to have lived together for a minimum of one year and to have similar dietary patterns. Participants were excluded if they had recent exposure to antibiotics or probiotics, autoimmune comorbidities, or known gastrointestinal disorders.
What were the most important findings?
The intestinal microbiota of RA patients differed significantly from that of healthy controls, and the microbiota of their cohabiting spouses exhibited an intermediate profile. A reduced Bacteroidetes-to-Firmicutes ratio was observed in both RA patients and spouses, driven by an enrichment of Firmicutes—particularly Streptococcus and Blautia—and a depletion of butyrate-producing, anti-inflammatory genera such as Roseburia and Lachnoclostridium. The microbial signatures of the spouses indicate that environmental factors, likely related to diet and shared living conditions, contribute to shaping gut dysbiosis in RA. Notably, Lachnoclostridium abundance positively correlated with patient age and RA disease duration, suggesting potential as a microbial marker for disease progression.
| Microbial Feature | RA Patients | Spouses | Healthy Controls | Clinical/Pathogenic Implications |
|---|---|---|---|---|
| Streptococcus spp. | Increased | Increased | Low | Pro-inflammatory; linked to autoimmune activation |
| Blautia spp. | Increased | Increased | Low | Associated with cytokine upregulation (IL-8, TNF-α) |
| Roseburia spp. | Decreased | Decreased | High | Butyrate producer; anti-inflammatory; marker of eubiosis |
| Lachnoclostridium spp. | Decreased | Decreased | High | Butyrate producer; inversely correlated with RA severity |
| Bacteroidetes:Firmicutes Ratio | Reduced | Reduced | Balanced | Indicator of metabolic dysregulation and inflammation |
| β-diversity (community structure) | Distinct from HC | Similar to RA | Distinct from RA/SP | Environmentally influenced; reflects dysbiotic convergence |
What are the greatest implications of this study?
The findings emphasize the significant role of shared environmental exposures in modulating intestinal microbiota and their potential impact on RA development. The intermediate dysbiotic profile observed in spouses supports the concept of a microbiota-mediated “pre-disease” state, which may predispose genetically susceptible individuals to immune dysregulation. The consistent enrichment of pro-inflammatory taxa (Streptococcus, Blautia) and loss of beneficial butyrate-producing genera (Roseburia, Lachnoclostridium) reinforce their classification as Major Microbial Associations (MMAs) in RA. These results suggest that microbiome-modifying strategies—such as personalized nutrition or probiotic supplementation—may be beneficial not only in RA management but also as preventive tools for at-risk populations. The study also supports incorporating microbiome profiling into RA risk assessment, particularly for first-degree relatives and long-term cohabitants.