Clinical and experimental observations in animal models indicate that intestinal commensal bacteria are
involved in the initiation and amplification of inflammatory bowel disease (IBD). As the majority of colonic
bacteria cannot be identified by culture techniques, the aim of this study was to use sequence-based methods
to investigate and characterize the composition of the dominant fecal microbiota in both patients with
inflammatory bowel disease and healthy subjects. Fecal microbiota was isolated and quantified using realtime
quantitative polymerase chain reaction. Denaturing gradient gel electrophoresis (DGGE) of 16S rDNA
was used to evaluate the diversity of the dominant species. Analysis of individual bacterial groups showed a
greater change in the fecal microbiota of patients with IBD, especially in those with active ulcerative colitis
and active Crohn's disease. DGGE demonstrated the diversity of microbial flora in ulcerative colitis and
Crohn's disease was less than in healthy subjects. Our results provide a better understanding of changes in
fecal microbiota among patients with inflammatory bowel disease.