Faecal microbiota and serum inflammatory markers in dogs with chronic enteropathy diagnosed with inflammatory bowel disease and small-cell lymphoma

Abstract

Dogs diagnosed with chronic enteropathy (CE), which includes inflammatory bowel disease (IBD) and small-cell lymphoma (SCL), exhibit marked differences in faecal microbiota and organic acid profiles compared with healthy dogs, as well as immune abnormalities in intestinal mucosal tissue. However, few studies have analysed trace organic acids, such as succinic acid, which have been suggested to be associated with IBD in humans. Therefore, in this study, we compared the faecal microbiota and organic acid profiles as well as serum inflammatory markers between dogs with CE (n = 11; 6 with IBD and 5 with SCL) and healthy controls (n = 16). We also performed machine learning and correlation analysis to obtain more detailed insights into the characteristics of affected dogs. These results revealed that dogs with CE had lower levels of Erysipelotrichaceae (e.g. Turicibacter and Allobaculum), exhibited abnormalities in the succinic acid metabolism (i.e. succinic acid accumulation and decreased levels of Phascolarctobacterium as succinic acid-utilising bacteria) and increased levels of pathogenic bacteria such as Escherichia-Shigella. Additionally, the presence of Dubosiella was significantly negatively correlated with Canine Inflammatory Bowel Disease Activity Index scores. These findings are expected to aid the development of microbiome-based medications and/or supplements, although further verification is needed.