PSXIII-7 Effects of high fat diets on metabolic parameters and markers of colonic permeability in dogs

Obesity and nutritional factors like high-fat diets (HFD) are associated with metabolic alterations, which result from the diet, bodyweight change or both. The objective was to determine the effects of HFD consumed either at maintenance or excess energy levels on BW, metabolic parameters, and colonic permeability markers. A HFD (35% fat as fed, 4923 kcal/kg) was given for 8wks to 24 healthy Beagle dogs, 8 at 100% (G1.0) and 16 at 150% (G1.5) maintenance energy levels for each individual dog. At baseline and after 8wks, basal leptinemia, ghrelinemia, glycemia and insulinemia were measured, while postprandial glycemia and insulinemia were determined for 6h following a challenge test meal. Colonic mucosa biopsies were performed and the expression of proteins involved in permeability was analyzed using RT-rtPCR. Results were analyzed using linear mixed model (nlme package; R) with dog as a random term (data rank-transformed where residuals not normally distributed). Ethics approval was granted by the French Ministry of Research and Royal Canin’s Ethical Committee. In the G1.5 group, increases in bodyweight (15%; P < 0.001), leptinemia (5±2 vs 2±1 ng/ml; P < 0.01), and postprandial insulin AUC (10405±2316 vs 6232±1368 μU.min.ml-1; P = 0.03) were observed at 8wks compared to baseline, whereas ghrelinemia decreased (552±361 vs 633±413 pg/ml; P = 0.04). No such change were observed in the G1.0 group. In both groups at 8wks, mRNA levels of claudin 2 (G1.0: P < 0.05; G1.5: P < 0.01) and syndecan (G1.0: P < 0.01; G1.5: P < 0.01) were higher compared to baseline, while mRNA levels of TJP1 (P < 0.01) increased in the G1.5 group. The changes observed in the G1.5 group but not in the G1.0 group suggest that the metabolic and hormonal parameters are related to weight gain but not to HFD alone. Furthermore, the mechanisms behind the modifications to colonic permeability markers observed in both groups remains to be elucidated.