Analysis of gut microbiota in discordant monozygotic twins with IBD to dissect the influence of genetic determination and environmental triggers

Abstract

INTRODUCTION: Although gut microbiota is known to be involved in inflammatory bowel diseases (IBD: Crohn´s disease (CD) and ulcerative colitis (UC)), the bacterial equilibrium leading to gut homeostasis and health remains unclear. Genetic predisposition has been clearly established in CD and gut microbiota could be important to understand the triggering events. We study monozygotic twins discordant for IBD who by definition share the same genetic background to search for bacterial species protecting the healthy twin or, alternatively, analyse bacterial dysbiosis in the diseased one. AIMS & METHODS: Six pairs of monozygotic (MZ) twins discordant for IBD (2 MZ-CD, 4 MZ-UC) and 12 pairs of healthy twins (6 MZ-H, 6 dizygotic (DZ-H)) were included. Local ethic committees approved the study. 16S rDNA libraries (4,200 clones) were constructed from sigmoid biopsies. Sequences were clustered in taxonomic units (OTUs) for each of the 36 libraries and assigned to their closest relatives using NCBI Blast. Diversity and statistical analyses were performed using DOTUR software and RDP library compare. [...].