An application of nuclear magnetic resonance spectroscopy to study faecal canine metabolome

Metabolomics provides a description of the phenotype of an organism and complementary biochemical information to genomics and proteomics. The purpose of this research was to depict the metabolite profile of faecal samples from dogs fed three different diets through NMR spectroscopy analysis. Samples were collected from 14 dogs fed a commercial extruded diet, 18 dogs fed a homemade diet and 16 dogs fed a raw meat-based diet. The average BCS for all dogs was 4–5 and the average Faecal Score was 2–3. Only healthy animals were considered, as assessed from the clinical evaluation of the veterinarians. Faecal samples were prepared using phosphate buffer (pH 7.1) combined with deuterated water and analysed with NMR spectroscopy using a Bruker Avance III HD 400 MHz spectrometer. Principal component analysis of the spectra signals demonstrated clustering of dogs according to diet, with 57.8% of the variance explained by the first three components. Targeted metabolome analysis was also performed on 56 metabolites of interest, selected from a database of 558 metabolites. Our data suggest that metabolome analysis using NMR is a promising approach to describe the phenotypic variation that occurs among dogs fed different diets. The metabolomic approach is becoming always more important in the evaluation of the functional responses of animals to dietary intervention. NMR-metabolomics has emerged as a non-destructive technique that allows a simpler data interpretation compared to other techniques. NMR metabolome analysis resulted to be a promising approach to describe the phenotypic variation that occurs among dogs fed different diets.