title: Characterization of the microbial communities along the gastrointestinal tract of sheep by 454 pyrosequencing analysis.
abstract: OBJECTIVE
  The gastrointestinal tract of sheep contain complex microbial communities that influence numerous aspects of the sheep's health and development. The objective of this study was to analyze the composition and diversity of the microbiota in the gastrointestinal tract sections (rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum, colon, and rectum) of sheep.
  
  
  METHODS
  This analysis was performed by 454 pyrosequencing using the V3-V6 region of the 16S rRNA genes. Samples were collected from five healthy, small tailed Han sheep aged 10 months, obtained at market. The bacterial composition of sheep gastrointestinal microbiota was investigated at the phylum, class, order, family, genus, and species levels.
  
  
  RESULTS
  The dominant bacterial phyla in the entire gastrointestinal sections wereFirmicutes,Bacteroidetes, andProteobacteria. In the stomach, the three most dominant genera in the sheep werePrevotella, unclassifiedLachnospiraceae, andButyrivibrio. In the small intestine, the three most dominant genera in the sheep wereEscherichia, unclassifiedLachnospiraceae, andRuminococcus. In the large intestine, the three most dominant genera in the sheep wereRuminococcus, unclassifiedRuminococcaceae, andPrevotella.R. flavefaciens,B. fibrisolvens, andS. ruminantiumwere three most dominant species in the sheep gastrointestinal tract. Principal Coordinates Analysis showed that the microbial communities from each gastrointestinal section could be separated into three groups according to similarity of community composition: stomach (rumen, reticulum, omasum, and abomasum), small intestine (duodenum, jejunum, and ileum), and large intestine (cecum, colon, and rectum).
  
  
  CONCLUSIONS
  This is the first study to characterize the entire gastrointestinal microbiota in sheep by use of 16S rRNA gene amplicon pyrosequencing, expanding our knowledge of the gastrointestinal bacterial community of sheep.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Tianjin Institute of Animal Husbandry and Veterinary Research, Tianjin 300384, China.|Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Fan
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Han
authors.affiliation: Tianjin Kuntai Environment & Energy Science and Technology Development Co., Ltd, Tianjin 300191, China.
authors.forename: Jinzhao
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Zhijiang
authors.initials: Z
authors.lastname: Zhou
keywords: Gastrointestinal Tract Sections; Microbiota; Pyrosequencing; Sheep