Biodiversity of the mucosa-associated microbiota is stable along the distal digestive tract in healthy individuals and patients with IBD.
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.
Lepage
Patricia
P
National Institute for Agromonic Research, Digestive Tract Ecology and Physiology Unit, Research Center, Jouy en Josas, France.
Seksik
Philippe
P
Sutren
Malène
M
de la Cochetière
Marie-France
MF
Jian
Raymond
R
Marteau
Philippe
P
Doré
Joël
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000382:microbiology* / Q000473:pathology; D003424:Crohn Disease / Q000382:microbiology* / Q000473:pathology; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D004755:Enterobacteriaceae / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007082:Ileum / Q000382:microbiology* / Q000473:pathology; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000473:pathology; D007420:Intestine, Large / Q000382:microbiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged
D004269:DNA, Bacterial; D004275:DNA, Ribosomal