Diversity of mucosa-associated microbiota in active and inactive ulcerative colitis

Objective. Recent findings indicate that bacteria play an important role in the pathogenesis of inflammatory bowel disease (IBD). However, the exact role of bacteria in ulcerative colitis (UC) has still to be elucidated. The objective of the study was to investigate the potential differences in the intestinal microbiota between patients with UC and control subjects, using terminal restriction fragment length polymorphism (T-RFLP) analysis of the mucosa-associated microbiota from UC patients and non-IBD controls. Material and methods. Nine active UC patients and 11 non-IBD controls were included in the study. Seven patients with active UC who entered into the inactive phase after antibiotic combination treatment were also classified as patients with inactive UC. Mucosa-associated microbiota was compared between non-IBD controls and UC patients using T-RFLP analysis. Microbiota in both the active and inactive phase was also analyzed in UC patients receiving antibiotic treatment. Results. T-RFLP patterns of mucosa-associated microbiota differed between active UC patients and non-IBD controls. Microbial compositions of active UC patients were significantly less diverse. The difference resulted from loss of commensals. From the viewpoint of disease activity before and after antibiotic combination treatment, T-RFLP patterns were also different between the active and inactive phases in the identical patients. Inactive UC patients possessed more diverse microbial compositions. No specific terminal restriction fragments were observed in UC patients. Conclusions. T-RFLP analysis showed that the mucosa-associated microbiota of patients with active UC differed from that of non-IBD controls. Active UC patients possessed significantly fewer diverse microbial compositions.