Biodiversity of the mucosa-associated microbiota is stable along the distal digestive tract in healthy individuals and patients with IBD

Inflamm Bowel Dis. 2005 May;11(5):473-80. doi: 10.1097/01.mib.0000159662.62651.06.


Background: The mucosa-associated microbiota, being very close to the inflammatory process associated with inflammatory bowel disease (IBD), may have a pathogenic role. We used a culture-independent method to analyze the mucosa-associated microbiota in IBD patients at various points of the distal digestive tract.

Methods: Thirty-five patients (20 with Crohn's disease, 11 with ulcerative colitis, and 4 controls) underwent colonoscopy. Biopsies (n = 126) were taken from 4 sites: the ileum, right colon, left colon, and rectum. Fecal samples were also obtained from 7 individuals. Temporal temperature gradient gel electrophoresis (TTGE) of 16S rDNA was used to evaluate dominant species diversity. TTGE profiles were compared using software that measures the degree of similarity.

Results: In a given individual, the overall similarity percentage between the 4 segments of the distal digestive tract was 94.7 +/- 4.0%, regardless of clinical status. The average similarity of all profiles for a given segment was 59.3 +/- 18.3% in the overall population. Dendrogram analysis showed that TTGE profiles did not cluster with clinical status. Differences were observed between the dominant fecal microbiota and the mucosa-associated microbiota of all 4 sites, with similarity percentages less than 92%.

Conclusions: These results confirm that the dominant species differ between the mucosa-associated and fecal microbiota. They also show that, in a given individual, the microbiota is relatively stable along the distal digestive tract, showing a slight evolution in dominant species diversity from the ileum to the rectum, in both healthy subjects and patients with IBD.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Colitis, Ulcerative / microbiology*
  • Colitis, Ulcerative / pathology
  • Crohn Disease / microbiology*
  • Crohn Disease / pathology
  • DNA, Bacterial / analysis
  • DNA, Ribosomal / analysis
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / isolation & purification*
  • Feces / microbiology
  • Female
  • Humans
  • Ileum / microbiology*
  • Ileum / pathology
  • Intestinal Mucosa / microbiology*
  • Intestinal Mucosa / pathology
  • Intestine, Large / microbiology*
  • Intestine, Large / pathology
  • Male
  • Middle Aged


  • DNA, Bacterial
  • DNA, Ribosomal