Faecal Bacterial Communities in Healthy Controls and Ulcerative Colitis Patients

Ulcerative colitis (UC) is an idiopathic inflammatory bowel disease (IBD) that is characterized by chronic inflammation of the colonic mucosa. The aetiology of IBD is not well understood, however the commensal intestinal microbiota is thought to play an important pathogenetic role. Hence, a detailed knowledge about the composition of the intestinal microbiota may be critical to unravel the pathogenesis of IBD. The aim of this study was to examine if the faecal microbiota of patients with UC differs from that of healthy subjects. Faecal samples were collected from healthy subjects and from UC patients with either clinically inactive or active disease. To analyse the composition of the faecal microbiota, we performed quantitative PCR (qPCR) using species and group-specific primers targeting Bifidobacterium spp., Lactobacillus spp., Firmicutes, Bacteroidetes and Faecalibacterium prausnitzii. Denaturing Gradient Gel Electrophoresis (DGGE) analysis using a universal primer targeting bacterial 16S rRNA genes were carried out in order to identify differences in species composition. The results obtained from the qPCR showed that the UC patients, irrespective of the stage of disease activity had a significantly lower amount of Bacteroidetes compared to the healthy controls (p