title: A Microbiological Map of the Healthy Equine Gastrointestinal Tract.
abstract: Horses are exquisitely sensitive to non-specific gastrointestinal disturbances as well as systemic and extraintestinal conditions related to gut health, yet minimal data are available regarding the composition of the microbiota present in the equine stomach, small intestine, and cecum and their relation to fecal microbiota. Moreover, there is minimal information regarding the concordance of the luminal and mucosal microbial communities throughout the equine gut. Illumina-based 16S rRNA gene amplicon sequencing of the luminal and mucosal microbiota present in seven regions of the gastrointestinal tract of nine healthy adult horses revealed a distinct compositional divide between the small and large intestines. This disparity in composition was more pronounced within the luminal contents, but was also detected within mucosal populations. Moreover, the uniformity of the gut microbiota was much higher in the cecum and colon relative to that in the stomach, jejunum and ileum, despite a significantly higher number of unique sequences detected in the colon. Collectively, the current data suggest that while colonic samples (a proxy for feces) may provide a reasonable profile of the luminal contents of the healthy equine large intestine, they are not informative with regard to the contents of the stomach or small intestine. In contrast to the distinct difference between the highly variable upper gastrointestinal tract microbiota and relatively uniform large bowel microbiota present within the lumen, these data also demonstrate a regional continuity present in mucosal microbial communities throughout the length of the equine gut.
authors.affiliation: University of Missouri Metagenomics Center, Department of Veterinary Pathobiology, University of Missouri, 4011 Discovery Drive, Columbia, MO, 65201, United States of America.|College of Veterinary Medicine, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.
authors.forename: Aaron C
authors.identifier: http://orcid.org/0000-0002-3053-7269
authors.initials: AC
authors.lastname: Ericsson
authors.affiliation: College of Veterinary Medicine, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.|Department of Veterinary Medicine and Surgery, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Johnson
authors.affiliation: College of Veterinary Medicine, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.|Department of Veterinary Medicine and Surgery, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Lopes
authors.affiliation: College of Veterinary Medicine, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.
authors.forename: Sonja C
authors.initials: SC
authors.lastname: Perry
authors.affiliation: College of Veterinary Medicine, University of Missouri, 1600 Rollins Road, Columbia, MO, 65211, United States of America.
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Lanter
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D015373:Bacterial Typing Techniques; D002432:Cecum / Q000382:microbiology; D003106:Colon / Q000382:microbiology; D004386:Duodenum / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000235:genetics*; D014644:Genetic Variation; D006736:Horses / Q000382:microbiology*; D007082:Ileum / Q000382:microbiology; D007583:Jejunum / Q000382:microbiology; D008297:Male; D009928:Organ Specificity; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D013270:Stomach / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology
chemical_list: D012336:RNA, Ribosomal, 16S