Reduced diversity of faecal microbiota in Crohn's disease revealed by a metagenomic approach.

Gut 2006 Feb 27;55(2):205-11. Epub 2005 Sep 27.

Unité d'Ecologie et de Physiologie du système Digestif, INRA-UEPSD, 78350 Jouy-en-Josas, France.

Background And Aim: A role for the intestinal microbial community (microbiota) in the onset and chronicity of Crohn's disease (CD) is strongly suspected. However, investigation of such a complex ecosystem is difficult, even with culture independent molecular approaches.

Methods: We used, for the first time, a comprehensive metagenomic approach to investigate the full range of intestinal microbial diversity. We used a fosmid vector to construct two libraries of genomic DNA isolated directly from faecal samples of six healthy donors and six patients with CD. Bacterial diversity was analysed by screening the two DNA libraries, each composed of 25,000 clones, for the 16S rRNA gene by DNA hybridisation.

Results: Among 1190 selected clones, we identified 125 non-redundant ribotypes mainly represented by the phyla Bacteroidetes and Firmicutes. Among the Firmicutes, 43 distinct ribotypes were identified in the healthy microbiota, compared with only 13 in CD (p<0.025). Fluorescent in situ hybridisation directly targeting 16S rRNA in faecal samples analysed individually (n=12) confirmed the significant reduction in the proportion of bacteria belonging to this phylum in CD patients (p<0.02).

Conclusion: The metagenomic approach allowed us to detect a reduced complexity of the bacterial phylum Firmicutes as a signature of the faecal microbiota in patients with CD. It also indicated the presence of new bacterial species.

Download full-text PDF

Source
http://dx.doi.org/10.1136/gut.2005.073817DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856500PMC
February 2006
1 Read

Publication Analysis

Top Keywords

metagenomic approach
8
crohn's disease
8
intestinal microbial
8
comprehensive metagenomic
4
clones 16s
4
approach investigate
4
25000 clones
4
range intestinal
4
full range
4
investigate full
4
time comprehensive
4
approachesmethods time
4
dna hybridisationresults
4
culture independent
4
hybridisationresults 1190
4
difficult culture
4
independent molecular
4
gene dna
4
composed 25000
4
rrna gene
4

Similar Publications