Reduction in diversity of the colonic mucosa associated bacterial microflora in patients with active inflammatory bowel disease.
OBJECTIVE
The intestinal bacterial microflora plays an important role in the aetiology of inflammatory bowel disease (IBD). As most of the colonic bacteria cannot be identified by culture techniques, genomic technology can be used for analysis of the composition of the microflora.


METHODS
The mucosa associated colonic microflora of 57 patients with active inflammatory bowel disease and 46 controls was investigated using 16S rDNA based single strand conformation polymorphism (SSCP) fingerprint, cloning experiments, and real time polymerase chain reaction (PCR).


RESULTS
Full length sequencing of 1019 clones from 16S rDNA libraries (n = 3) revealed an overall bacterial diversity of 83 non-redundant sequences-among them, only 49 known bacterial species. Molecular epidemiology of the composition of the colonic microflora was investigated by SSCP. Diversity of the microflora in Crohn's disease was reduced to 50% compared with controls (21.7 v 50.4; p<0.0001) and to 30% in ulcerative colitis (17.2 v 50.4; p<0.0001). The reduction in diversity in inflammatory bowel disease was due to loss of normal anaerobic bacteria such as Bacteroides species, Eubacterium species, and Lactobacillus species, as revealed by direct sequencing of variable bands and confirmed by real time PCR. Bacterial diversity in the Crohn's group showed no association with CARD15/NOD2 status.


CONCLUSIONS
Mucosal inflammation in inflammatory bowel disease is associated with loss of normal anaerobic bacteria. This effect is independent of NOD2/CARD15 status of patients.
Ott
S J
SJ
Department of General Internal Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
Musfeldt
M
M
Wenderoth
D F
DF
Hampe
J
J
Brant
O
O
Fölsch
U R
UR
Timmis
K N
KN
Schreiber
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D001421:Bacteria, Anaerobic / Q000302:isolation & purification; D002352:Carrier Proteins / Q000235:genetics; D003106:Colon / Q000382:microbiology*; D003424:Crohn Disease / Q000235:genetics / Q000382:microbiology; D005260:Female; D015723:Gene Library; D005838:Genotype; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000382:microbiology; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D018807:Polymorphism, Single-Stranded Conformational; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D012336:RNA, Ribosomal, 16S