The Different Effects And Mechanisms Between Whole Foods Diets And Purified Diets On Lipid And Glucose Metabolism In Mice

Objective: This study aimed to investigate the difference between the effects of whole foods diet(whole foods diet,WFD)and the purified diet(purified diet,PD)on the glycolipid metabolism in the liver of C57BL/6J male mice as well as their mechanisms.To explore whether PD model could scientifically replace WFD model in the glycolipid metabolism study of animal models,and to provide a reference for the correct selection of feed models in related animal models.Methods:(1)Sixty 8-week-old C57BL/6J male mice were randomly divided into four groups(n =15/group),which were fed PD supplemented with lard(PD-LO),and soybean oil(PD-SO),as well as WFD supplemented with lard(WFD-LO)and soybean oil(WFD-SO).The growth performance data was collected during the entire trial period,and the body fat rate,blood lipids,liver and kidney function index and liver lipids deposition were measured after 16 weeks of feeding.(2)Sixty 8-week-old C57BL/6J male mice were randomly divided into four groups(n =15/group),which were fed the same oil and fat energy level is 25% PD(PD-25)and WFD(WFD-25),as well as fat energy level is 45% PD(PD-45)and WFD(WFD-45).The growth performance data was collected during the entire trial period,after 24 weeks of feeding,the body fat rate,blood lipids,liver and kidney function index,liver lipid deposition,the m RNA and protein relative expression of glucolipid metabolism-related genes in liver tissue as well as lipid absorption related genes in the small intestine tissues were measured.Result:(1)The results based on the PD conditions showed that the intake of soybean oil could increase the body weight,white fat weight,body fat percentage,serum cholesterol and liver triglyceride content when compared with lard(P<0.05).However,there were no significant effects on glucose tolerance of mice(P>0.05).The results based on the WFD conditions showed that compared with soybean oil,the intake of lard significantly increased body weight,body fat percentage,cholesterol and triglyceride contents in liver of mice(P<0.05),as well as significantly increased serum lipid content of mice(P<0.01).In conclusion,the WFD supplemented with lard is more likely to cause obesity and glucolipid metabolism disorders in mice.When compared with the PD at high lipid level(45%),the intake of WFD significantly increased body weight,body fat percentage,blood glucose as well as lipid levels,and liver triglyceride content(P<0.01),leading to more severe fatty liver and liver injury in mice.In addition,the mice insulin secretion capacity and sensitivity were weakened more easily when fed the WFD(P<0.01).(3)At high lipid level,compared with the PD,the WFD mainly induced lipid accumulation in the liver through two pathways: upregulating the m RNA expression of lipid absorption and transport-related proteins in the small intestine and liver,as well as activating the IRS1-PI3K-Akt-MTOC1 pathway to significantly upregulate the expression of fatty acid biosynthesis related genes(4)(4)At high lipid levels,compared with the PD,the intake of WFD was more likely to induce mice insulin resistance,which resulted in decreased glucose absorption and enhanced gluconeogenesis,and led to a significant increase in blood glucose levels of mice(P<0.01).Conclusion: The effect of WFD and PD with the same dietary oil on glucolipid metabolism in mice was significantly different or extremely significant under the conditions of low and medium fat energy(25%)as well as high fat energy(45%).Compared with the PD,the high fat WFD was more likely to cause glucolipid metabolism disorder in mice.The mechanism is mainly to promote the synthesis of fatty acids and increase the absorption and transport of fatty acids in intestinal epithelial cells via the activation of IRS1-PI3K-Akt-m TOR signaling pathway.Therefore,there may be some systematic errors or errors in the conclusions of glucolipid metabolism study by simply replacing the WFD with PD.