Skip to main content
Research article - Peer-reviewed, 2008

Molecular analysis of the gut microbiota of identical twins with Crohn's disease

Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt; Apajalahti, Juha; Engstrand, Lars; Jansson, Janet K.


Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independent of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n = 6 and concordant n 4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group-specific primers. The microbial communities were also profiled based on their percentage G + C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and higher relative abundances of B. ovatus and B. vulgatus. Our results suggest that genetics and/or environmental exposure during childhood, in part, determine the gut microbial composition. However, CD is associated with dramatic changes in the gut microbiota and this was particularly evident for individuals with ileal CD.


Crohn's disease; terminal-restriction fragment length polymorphism (T-RFLP); discordant twins; concordant twins; Bacteroides

Published in

ISME Journal
2008, volume: 2, number: 7, pages: 716-727

Authors' information

Swedish University of Agricultural Sciences, Department of Microbiology
Halfvarson, Jonas
Örebro University Hospital
Swedish University of Agricultural Sciences, Department of Microbiology
Järnerot, Gunnar
Örebro University Hospital
Tysk, Curt
Örebro University Hospital
Apajalahti, Juha
Alimetrics Ltd
Engstrand, Lars
Swedish Institute for Infectious Disease Control
Jansson, Janet
Swedish University of Agricultural Sciences, Department of Microbiology
Jansson, Janet
Lawrence Berkeley National Laboratory (Berkeley Lab)

UKÄ Subject classification


Publication Identifiers


URI (permanent link to this page)