title: Comparative analysis of gastrointestinal microbiota between normal and caudal-related homeobox 2 (cdx2) transgenic mice.
abstract: OBJECTIVE
  Caudal-related homeobox 2 (Cdx2) is expressed in the human intestinal metaplastic mucosa and induces intestinal metaplastic mucosa in the Cdx2 transgenic mouse stomach. Atrophic gastritis and intestinal metaplasia commonly lead to gastric achlorhydria, which predisposes the stomach to bacterial overgrowth. In the present study, we determined the differences in gut microbiota between normal and Cdx2 transgenic mice, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR).
  
  
  METHODS
  Twelve normal (control) and 12 Cdx2 transgenic mice were sacrificed, and the gastric, jejunal, ileac, cecal and colonic mucosa, and feces were collected. To quantitate bacterial microbiota, we used real-time qRTPCR with 16S rRNA gene-targeted, species-specific primers.
  
  
  RESULTS
  The total numbers of bacteria in the gastric, jejunal, ileac, cecal, and colonic mucosa of the Cdx2 transgenic mice were significantly higher than those of the normal mice. The Bacteroides fragilis group and also Prevotella were not detected in the stomach of the normal mice, although they were detected in the Cdx2 transgenic mice. Moreover, the Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, and Prevotella were not detected in the jejunum or ileum of the normal mice, although they were detected in the Cdx2 transgenic mice. The fecal microbiota of the normal mice was similar to that of the Cdx2 transgenic mice.
  
  
  CONCLUSIONS
  Our results showed the differences in composition of gut microbiota between normal and Cdx2 transgenic mice, which may be caused by the development of gastric achlorhydria and intestinal metaplasia in Cdx2 transgenic mice.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Yakult Honsha Co., Ltd., Yakult Central Institute, Kunitachi, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Asahara
authors.affiliation: Yakult Honsha Co., Ltd., Yakult Central Institute, Kunitachi, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Chonan
authors.affiliation: Yakult Honsha Co., Ltd., Yakult Central Institute, Kunitachi, Japan.
authors.forename: Norikatsu
authors.initials: N
authors.lastname: Yuki
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mutoh
authors.affiliation: Department of Microbiology, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Hayashi
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sugano
keywords: 16S rRNA; Cdx2; Gastric achlorhydria; Intestinal metaplasia; Microbiota