PR000372 (Project)

Description:Introduction: The fecal microbiome is relevant to the health and disease of many species. The importance of the fecal metabolome has more recently been appreciated, but our knowledge of the microbiome and metabolome at other sites along the gastrointestinal tract remains deficient. Objective: To analyze the gastrointestinal microbiome and metabolome of healthy domestic dogs at four anatomical sites. Methods: Samples of the duodenal, ileal, colonic, and rectal contents were collected from six adult dogs after humane euthanasia for an unrelated study. The microbiota were characterized using Illumina sequencing of 16S rRNA genes. The metabolome was characterized by mass spectrometry-based methods. Results: Prevalent phyla throughout the samples were Proteobacteria, Firmicutes, Fusobacteria, and Bacteroidetes, consistent with previous findings in dogs and other species. A total of 530 unique metabolites were detected; 199 of these were identified as previously named compounds, but 141 of them had at least one significantly different site-pair comparison. Noteworthy examples include amino acids, which decreased from the small to large intestine; pyruvate, which was at peak concentrations in the ileum; and several phenol-containing carboxylic acid compounds that increased in the large intestine. Conclusion: The microbiome and metabolome vary significantly at different sites along the canine gastrointestinal tract.