Evaluation of Changes in Metabolites of Saliva in Canine Obesity Using a Targeted Metabolomic Approach

SIMPLE SUMMARY: The growing problem of obesity in dogs has become an epidemic that affects their quality of life. This study shows for the first time the changes in salivary metabolites in dogs with obesity using a targeted metabolomic approach. The analysis revealed alterations in 27 metabolites classified as amino acids, glycerides, sphingolipids, glycerophospholipids, and acylcarnitines. Some of the changes in the metabolites found in the saliva of obese dogs are associated with insulin resistance, which is usually related to obesity. These results indicate that saliva can show changes in its metabolites in canine obesity, making it a valuable source of biomarkers for this condition. ABSTRACT: Obesity is a common problem in pet dogs, affecting half of the general population in some countries. Excess body weight causes several disorders and has a negative impact on dogs’ quality of life. The use of metabolomics allows the identification of metabolite traces from the metabolic pathways involved in pathological processes. This study aimed to evaluate salivary metabolite variations in dogs with obesity. The salivary samples of 19 dogs were analyzed using a targeted metabolomic approach, through which 234 metabolites were quantified. Of these, multivariate analysis identified 27 different metabolites altered in dogs with obesity compared with control dogs. These metabolites were mainly classified as amino acids, glycerides, sphingolipids, glycerophospholipids, and acylcarnitines. Some of the changes in these metabolites reflect the insulin resistance status related to obesity in dogs. Overall, it can be concluded that the salivary metabolome of obese dogs reflects the metabolic changes occurring in obesity and could be a source of potential biomarkers for this complex condition.