Fecal microbiome in dogs with inflammatory bowel disease and intestinal lymphoma

Marie OMORI, Shingo MAEDA, Hirotaka IGARASHI, OHNO Koichi, Kosei SAKAI, Tomohiro YONEZAWA, Ayako HORIGOME, Toshitaka ODAMAKI, Naoaki MATSUKI

Although alteration of commensal microbiota is associated with chronic gastrointestinal (GI) diseases such as inflammatory bowel disease (IBD) in dogs, the microbiota composition in intestinal lymphoma, an important differential diagnosis of canine IBD, has not been investigated. The objective of this study was to compare the fecal microbiota in dogs with IBD, dogs with intestinal lymphoma, and healthy dogs. Eight dogs with IBD, eight dogs with intestinal lymphoma, and fifteen healthy dogs were included in the study. Fecal samples were analyzed by 16S rRNA gene next-generation sequencing. Rarefaction analysis failed to reveal any difference in bacterial diversity among healthy dogs and diseased dogs. Based on PCoA plots of unweighted UniFrac distances, the bacterial composition in dogs with intestinal lymphoma was different from those observed in dogs with IBD and healthy dogs. When compared with healthy dogs, intestinal lymphoma subjects showed significant increases in organisms belonging to the Eubacteriaceae family. The proportion of the family Paraprevotellaceae and the genus Porphyromonas was significantly higher in dogs with IBD compared to healthy dogs. These observations suggest that dysbiosis is associated with intestinal lymphoma as well as IBD in dogs.