Topical Area: Energy and Macronutrient Metabolism, Obesity
Previously we developed the Total Western Diet (TWD), a diet formulated by translating data from NHANES to a rodent diet using the concept of nutrient density. The TWD provides micro and macronutrients at the 50th percentile of daily American intake levels for both macro and micronutrients. To extend the model, the TWD for pigs was formulated and fed to pigs to determine the effects of the TWD on the plasma and follicular fluid (FF) lipidomes and the hepatic lipid profile.
Ten female, mature pigs were assigned to either the TWD (n=5) or a control, low-fat commercial sow diet (n=5). Pigs were fed for 12 weeks and allowed ad lib access to diets. Weights and food intake were measured weekly. Plasma and FF samples were collected at the end of the study to determine effects of treatment on the plasma and FF lipidomes as analyzed by LC-MS. Liver samples were also taken at the terminus of the study and the hepatic lipid profile was measured by GC-MS.
Pigs fed the TWD gained significantly more weight, 92.8 ± 9.5 vs. 54.2 ± 11.2 kg (p < 0.001) and had an increased fasted blood glucose, 123.2 ± 13.7 vs 91.4 ± 7.9 mg/dl (p < 0.01) compared to control pigs. There were 23 plasma lipid metabolites that were significantly affected by dietary treatment (p < 0.05). Interestingly, out of that total, 14 of those were sphingomyelin species, which were all increased in the TWD fed pigs. Similarly, in the FF, eight lipid metabolites were significantly different between treatments, including four sphingomyelin species, which were all higher in the TWD fed pigs. Pigs fed the TWD had significantly more hepatic non-esterified fatty acids (p < 0.05) compared to controls. Moreover, dihomo-gamma-linolenic acid was significantly higher in the triglyceride and free fatty acid lipid classes in pigs fed the TWD relative to pigs fed the control diet (p < 0.05).
Conclusions : These data demonstrate that some features of human metabolic syndrome are recapitulated in pigs fed a diet that emulates the American dietary pattern. Furthermore, these features are accompanied by changes to the plasma and FF lipidome, as well as the hepatic lipid profile in female pigs. These data suggest that sphingomyelin species in plasma and FF may be associated with overfeeding and metabolic syndrome.
Funding Sources :
Utah State University SPARC Award and Utah Agricultural Experiment Station