Differential Expression Effects On High Fat Diet With Different Doses Of Resistant Starch

With the rapid development of the economy and the improvement of living standards,the number of people with high-fat diets rich in saturated fat is increasing in China,which leads to rapid weight growth,overweight or even obesity,and increased risk of some chronic diseases such as diabetes and cardiovascular diseases.Resistant starch can increase the dietary fiber content in foods,improve sensory properties,meanwhile people have higher acceptance of food adding resistant starch.The aim of this study was to evaluate the differential expression effect of high-fat diet with different doses of resistant starch by intervening normal SD rats with high-fat fodder adding 10%,15%,20%high-amylose corn starch.Due to feed different fodder,thirty normal SD rats randomly were divided into five groups,including normal diet group,high fat diet group,low-dose resistant starch group,medium-dose resistant starch group,high-dose resistant starch group,of which three intervention groups were added high-amylose corn starch with dose of 10%,15%,20%respectively.The rats’ body weight situation was recorded during the 36 weeks intervention.Hepatic and colon paraffin sections were prepared by HE staining;serum TG,T-CHO,HDL-C,LDL-C content,AKP,GPT,GOT activity,insulin,leptin,GLP-1,YY peptide concentration were measured;the content of short chain fatty acids in feces was determined by gas chromatography;the 16S rDNA amplicon sequencing of feces and the transcriptome analysis of liver were performed;the relative expression of genes related to glucose and lipid metabolism in the liver were determined.The different doses of high-amylose corn starch had a slowing effect on the weight gain of high-fat diet rats.Through observation of the animal organization slice,the intervention group can reduce the accumulation of fat in the liver,and maintain the integrity of the colon structure.The three intervention groups all reduced the levels of TG,T-CHO and LDL-C in serum of rats with high-fat diet,and increased the content of HDL-C;the activity of AKP,GPT,GOT and the concentration of insulin and leptin in serum were all decreased;the concentrations of GLP-1 and PYY were all increased.The MRS group had the best improvement.High-amylose corn starch is beneficial to reduce the content of isobutyric acid in the feces of rats on high-fat diet,which to some extent indicates that the protein fermentation reaction in the intestinal tract is reduced,thus regulating the intestinal environment.Compared with other groups,the MRS group had a higher butyric acid ratio,which may promote the lipodieresis.The beneficial bacteria that can produce short chain fatty acids in intestinal microbes have higher relative abundance in the intervention group,while the Ruminococcaceae that can cause obesity and the Desulfovibrio that can destroy the intestinal barrier have lower relative abundance.The expression of genes related to glucose and lipid metabolism in liver indicate that high-amylose corn starch can inhibit the glycolysis/gluconeogenesis pathway and act the biosynthesis of cholesterol,fatty acids and triglycerides.In conclusion,high-amylose corn starch has a good intervention effect on high-fat diet,especially the dose of 15%shows a better intervention effect,which provides a theoretical basis for the application of high-amylose corn starch in food to improve the health status of people with high-fat diet structure and the appropriate amount of addition.