Alterations in fecal microbiota in patients with inflammatory bowel disease and enteropathic arthropathy

Objectives: Inflammatory arthritis or enteropathic arthropathy (EA) is a common extra-intestinal manifestation in patients with inflammatory bowel disease (IBD). We aimed to determine whether EA in patients with IBD was associated with changes in the gut microbiome. Methods: Consecutive patients with ulcerative colitis (UC) or Crohn's disease (CD) were prospectively recruited and characterized. Stool samples were collected and real-time polymerase chain reaction targeting 16S ribosomal RNA genes was used to quantitate specific communities of “beneficial”; (Clostridium coccoides, bifidobacteria, and lactobacilli) or “aggressive” (Bacteroides and Enterobacteriaceae) bacterial flora. In 12 patients with UC and 12 with CD, fecal 16S ribosomal RNA gene was subjected to next-generation sequencing (NGS) and bacterial taxa were enumerated and compared between IBD patients with and without EA. Results: Sixty-eight patients with UC and 60 with CD were included in the study. Arthropathy was noted in 13 (21.6%) patients with CD and 11 (16.1%) patients with UC. Arthritis was peripheral in 12, axial in 7, and mixed in the rest. The most prevalent commensal bacteria in IBD patients were Bacteroides and Bifidobacterium. Enterobacteriaceae count was significantly higher in patients with UC than in CD. UC patients with EA had relatively higher Enterobacteriaceae and lesser C. coccoides than UC patients without EA. The NGS analyses showed a significant reduction in alpha diversity in patients with EA compared to IBD without EA. Patients with EA had significantly greater abundance of enterococci compared to IBD without EA. Conclusions: EA in IBD patients is characterized by gut microbiome changes including dysbiosis, reduction in alpha diversity, and increased abundance of enterococci.