Prevalence of Bacteroides and Prevotella spp. in ulcerative colitis.

The resident bacterial flora of the large intestine has become increasingly recognized as an essential component in the pathogenesis of ulcerative colitis (UC). However, it is still not known whether the bacterial flora in general or certain bacterial species of the intestinal microbial flora contribute to the pathogenesis of the disease. In order to investigate the composition of the mucosa-associated microbial flora in UC, mucosal tissue samples from patients with active UC and from control subjects with non-inflammatory conditions were analysed and compared.