P675. Alterations in composition and diversity of the intestinal microbiota in Korean Crohn's disease patients
C.S. Eun1, D.S. Han1, A.R. Lee1, D.I. Park2, S.-K. Yang3, 1Hanyang University Guri Hospital, Gastroenterology, Guri, Korea, Republic of, 2Sungkyunkwan University, Gastroenterology, Seoul, Korea, Republic of, 3Ulsan University, Gastroenterology, Seoul, Korea, Republic of
An altered intestinal microbial composition (dysbiosis) is associated with intestinal inflammation in inflammatory bowel disease, which are characterized by decreased bacterial diversity and an altered ratio of beneficial and aggressive bacterial species. We analyzed intestinal microbial profiles of feces and mucosal tissues from Korean Crohn's disease (CD) patients and healthy controls (HC) using high-throughput sequencing.
Fecal or mucosal tissue DNA were isolated from 35 CD patients and 31 HC. Variable regions V1-V3 of the 16S rRNA gene were amplified from all samples. PCR products were sequenced using 454 GS FLX Titanium sequencing. The composition, diversity and richness of microbial communities were determined and compared between CD and HC.
Intestinal microbial profile of fecal samples in Korean HC was similar to Western HC data with predominant proportions of phyla Firmicutes and Bacteroidetes. Global structure and individual bacterial abundance were different between feces and ileal tissues in HC. Ileal tissues of active CD patients had higher level of phylum Proteobacteria, lower level of phylum Firmicutes, and decreased bacterial diversity compared to HC. The proportion of phylum Fusobacteria was significantly higher in active CD patients compared to HC and CD patients in remission.
Our 16S rRNA sequence data demonstrates a community-level dysbiosis in Korean IBD patients. Fecal microbiota analysis does not effectively reflect ileal bacterial community structure.