Microbial Characterization, Metabolomic Profiling, and Bile Acid Metabolism in Healthy Dogs and Dogs with Chronic Enteropathy

Abstract

Chronic gastrointestinal disease in dogs can manifest itself in many different ways including vomiting, diarrhea, and weight loss. Bile acid dysmetabolism has recently been recognized as an important component of chronic gastrointestinal disease (e.g., Crohn’s disease, Ulcerative Colitis, Irritable Bowel Syndrome, and Inflammatory Bowel Disease) in humans. The aim of this research was to evaluate bile acid dysmetabolism in chronic enteropathy of dogs. An assay for the measurement of unconjugated fecal bile acids using gas chromatography coupled with mass spectrometry was developed.

The assay was accurate and reproducible. The percent of unconjugated secondary bile acids were significantly decreased in dogs with chronic enteropathy (p=0.0161), with approximately 60% of dogs having bile acid dysmetabolism. The percent of unconjugated secondary bile acids significantly increased in patients with chronic enteropathy after steroid therapy (p=0.0183). The effect of cholestyramine, a bile acid sequestrant, was evaluated for the ability to alter the fecal bile acid pool in healthy dogs. The concentration of secondary bile acids significantly increased in feces of healthy dogs administered cholestyramine (p=0.0183). These results demonstrate that a subset of dogs with chronic enteropathy show fecal bile acid dysmetabolism, and further studies are warranted to evaluate the use of bile acid sequestrants in clinical cases.