title: Imbalance in intestinal microflora constitution could be involved in the pathogenesis of inflammatory bowel disease.
abstract: Since genetically engineered animal models of inflammatory bowel disease (IBD) do not develop colitis under germ-free conditions, the intestinal microflora is thought to be one of the most important environmental factors associated with IBD. To understand the involvement of intestinal microflora in the pathogenesis of IBD, we analyzed the constituents of intestinal microflora in IBD. Faecal samples from 73 patients with ulcerative colitis (UC) and 23 patients with Crohn's disease (CD) were analyzed by quantitative PCR using 16S rRNA gene-targeted group-specific primers for Bacteroides fragilis group, Bifidobacterium, Clostridium coccoides groups, Clostridium leptum subgroup, Atopobium cluster, and seven species of Bacteroides. We analyzed the distribution of the predominant microflora by fluorescence in situ hybridization (FISH) using group-specific probes. We also examined the concentration of faecal organic acids produced by intestinal microflora. Contrary to previous reports, we found that the B. fragilis group was significantly decreased in the faeces of patients with IBD. Moreover, B. vulgatus was the predominant microflora in healthy controls and relatively decreased among IBD patients. Most of the microflora adhering to the colonic mucosa surrounding the mucus layer comprised C. coccoides group and Bifidobacterium. B. fragilis group mainly inhabited the faeces, but did not adhere to or invade the mucosa. The concentrations of propionic and butyric acids in the faeces were significantly decreased in patients with IBD. These findings indicate that IBD is not caused by a specific intestinal bacterial cluster or species and that disordered intestinal microflora could be involved in the pathogenesis of IBD.
authors: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors: Hiromasa
authors: H
authors: Takaishi
authors: Takahiro
authors: T
authors: Matsuki
authors: Atsushi
authors: A
authors: Nakazawa
authors: Toshihiko
authors: T
authors: Takada
authors: Shoichi
authors: S
authors: Kado
authors: Takashi
authors: T
authors: Asahara
authors: Nobuhiko
authors: N
authors: Kamada
authors: Atsushi
authors: A
authors: Sakuraba
authors: Tomoharu
authors: T
authors: Yajima
authors: Hajime
authors: H
authors: Higuchi
authors: Nagamu
authors: N
authors: Inoue
authors: Haruhiko
authors: H
authors: Ogata
authors: Yasushi
authors: Y
authors: Iwao
authors: Koji
authors: K
authors: Nomoto
authors: Ryuichiro
authors: R
authors: Tanaka
authors: Toshifumi
authors: T
authors: Hibi
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D001439:Bacteroides / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001644:Bifidobacterium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D044822:Biodiversity; D020148:Butyric Acid / Q000032:analysis; D003013:Clostridium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D015169:Colony Count, Microbial / Q000379:methods; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015212:Inflammatory Bowel Diseases / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000382:microbiology; D007422:Intestines / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011422:Propionates / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D011422:Propionates; D012336:RNA, Ribosomal, 16S; D020148:Butyric Acid; C029658:propionic acid