Untargeted global metabolomic profiling of healthy dogs grouped on the basis of grain inclusivity of their diet and of dogs with subclinical cardiac abnormalities that underwent a diet change

Abstract

OBJECTIVE To compare metabolomic profiles of dogs eating grain-free (GF) versus grain-inclusive (GI) diets (1) for healthy dogs at baseline and (2) for dogs with subclinical cardiac abnormalities at 12 months after a diet change. SAMPLE Serum samples from 23 dogs eating GF diets and 79 dogs eating GI diets, of which 17 (8 eating a GF diet and 9 eating a GI diet) were reevaluated 12 months after a diet change. PROCEDURES Metabolomic profiles were developed by means of ultrahigh-performance liquid chromatography–tandem mass spectroscopy of serum samples. Baseline results for the GF group were compared with those for the GI group. Dogs from both groups with subclinical cardiac abnormalities were transitioned to a GI, pulse-free, intervention diet, and samples collected 12 months later were compared between diet groups. Statistical significance for biochemical group differences was defined as P < .05 with a false discovery rate (q) < .10. RESULTS Baseline differences in lipid metabolism and amino acid metabolism were found between the GF and GI diet groups. There were 46 metabolites that were higher and 82 metabolites that were lower in the GF group (n = 23), compared with the GI group (79). Comparison of the GF (n = 8) and GI (9) groups 12 months after the diet change showed only 6 metabolites that were higher and 11 metabolites that were lower in the GF group, compared with the GI group. CLINICAL RELEVANCE Metabolomic pathway differences between dogs eating GF versus GI diets highlight the important effect of diet in metabolomics analyses. The clinical importance of these differences and how they might relate to cardiac disease in dogs remains undetermined.

Metabolomic profiling in dogs with dilated cardiomyopathy eating non-traditional or traditional diets and in healthy controls

“…The unnamed metabolite, X-25419, was significantly higher in both the disease-and diet-based comparisons at baseline and decreased significantly after the 9-month intervention. The findings of higher X-25419 at baseline and significant decreases after a dietary www.nature.com/scientificreports/ intervention are consistent with results from our prior foodomics study, as well as from a recent study of apparently healthy dogs eating grain-free or grain-inclusive diets at baseline and, in a subset of dogs with subclinical cardiac abnormalities, 12 months after diet change 31 . Surprisingly, in that study, X-25419 levels remained higher after 12 months in dogs with subclinical cardiac abnormalities originally eating grain-free diets compared to those originally eating grain-inclusive diets.…”

Comparison of echocardiography, biomarkers and taurine concentrations in cats eating high- or low-pulse diets

“…12,17 Definitions for associated diets have varied among studies and have been refined over time as new data have been published on this disease. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]23 Highpulse diets in our study were defined as those having at least one pulse in the top-five ingredients or at least two pulses in the top-10 ingredients on the diet's ingredient list, whereas many of the studies in dogs have defined 'non-traditional' diets as those containing pulses/ potatoes in the top-10 ingredients or those classified as 'grain-free'. This definition might require further refinement, and the pulse score may be helpful in the future for defining study groups.…”

“…The current study’s median pulse and pulse/potato scores in the high-pulse group were lower than in previous studies of dogs with DCM or subclinical cardiac abnormalities eating non-traditional/grain-free diets. 8 , 16 Therefore, the ‘dose’ of pulses cats were receiving could have been insufficient to be associated with echocardiographic and cardiac biomarker differences.…”

“…Diet pulse and pulse/potato scores for each cat were calculated as previously described. 8 , 16 If a cat was eating more than one diet, the diet with the highest pulse score was used for that cat’s diet pulse score.…”

“…11 In addition to overt DCM, these diets have also been associated with earlier, subclinical abnormalities in cardiac size and function or elevated cardiac biomarkers. [12][13][14][15][16][17] Although the cause of this diet-associated DCM (daDCM) is unknown, it is speculated that it could be due to a deficiency or toxicity resulting from ingredients in these diets. In contrast to primary DCM, which is typically a progressive disease, many dogs with daDCM have improvements in cardiac size and function, or even resolution of heart disease after a diet change; dogs whose diets are changed also have a longer survival time than dogs with primary DCM.…”