P118 Identification of colitis-associated bacteria in intestine of inflammatory bowel disease patients

• Published in: Journal of Crohn's and Colitis Vol. 12; no. supplement_1; p. S152
• Main Authors: Seishima, J, Iida, N, Mizukoshi, E, Kaneko, S
• Format: Journal Article
• Language: English; Japanese
• Published: UK Oxford University Press (OUP) 16.01.2018; Oxford University Press
• ISSN: 1873-9946; 1876-4479
• DOI: 10.1093/ecco-jcc/jjx180.245

Abstract Background Dysbiosis of intestinal flora in patients of inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn’s disease (CD) is closely related to intestinal inflammation. To clarify relationship between bacteria and colitis, it is necessary to use the stools of patients to reproduce colitis in animals. In this study, we clarified the characteristics of IBD intestinal flora by metagenomic analysis and identified bacteria causing intestinal inflammation in a mouse model. Methods Whole genome shotgun sequencing was performed on the stool DNA of 16 UC patients, 8 CD patients, and 13 healthy donors (HD). The composition of bacterial flora was compared by linear discriminant analysis (LDA). Intestinal flora of IL10-deficient mice, a model mouse of spontaneous colitis, was sterilised using antibiotics, and the feces of the subjects were transplanted into mice. We compared body weight change, intestinal pathology score, and expression of inflammatory cytokines (tnf, il6, il1b, il12b, il17, and il23a) of intestinal tissue using real-time PCR at 28 days after transplantation. We characterised the bacterial flora of the mice after stool transplantation using amplification sequencing of the 16S rRNA region. In addition, we administered specific bacteria to mice and observed inflammation and body weight change. Results Compared with the bacterial flora of the HD patients, there were 43 different bacterial taxonomies in the UC patients and 56 differences in the CD patients (p < 0.05). In particular, Enterococcus faecium in UC and E. coli in CD had the highest LDA scores. In addition, weight gain was less in the UC group than in the HD group, but there was no significant difference between the CD group and the HD group. The pathology score was higher in the UC group than in the HD group, and the expression levels of tnf, il1b, and il17 increased in the UC group. In the bacterial flora of the UC group after transplantation, bacteria of the Enterococcus genus were significantly more abundant than those of the HD group (p < 0.05). Mice administered E. faecium showed less weight gain, higher pathology score, and higher expression levels of tnf, il1b, il12b, and il17 than those administered the HD feces. Conclusions The intestinal bacterial flora of UC patients induces colitis and E. faecium might be one of the bacteria causing intestinal inflammation.