Effects Of Lactobacillus Casei YBJ02 On Lipid Metabolism In Hyperlipidemic Mice

With the improvement of living standards,lifestyle changes,hyperlipidemia can induce atherosclerosis,and become the primary risk factors,and high blood sugar,high blood pressure,nonalcoholic fatty liver disease,cholelithiasis and other diseases are closely related,serious harm to human life and health,is known as one of "the three major killers." The development of probiotics with potent hypolipidemic function is significant to alleviate the problem of high blood lipids in humans.Traditional fermented yak yogurt as Tibetan dairy products,not only has a wealth of nutritional value,but also contains a wealth of probiotics resources.A probiotic strain with potential effect was isolated from yak yoghurt,then the animal model of hyperlipidemia was measured by blood index and the expression of lipid metabolism in mice,to evaluate the effect and mechanism of Lactobacillus casei YBJ02 on lipid metabolism in hyperlipidemic mice(1)Through molecular biology identification of 18 untransformed Lactobacillus preserved in laboratory,there were four strains of Lactobacillus casei strain,nine strains of Lactobacillus fermentum strain and 5 strains of Lactobacillus plantarum strain.No.1 strain(Lactobacillus casei strain)was screened as an excellent strain by antacid,anti-bile salt,hydrophobic and cholesterol-lowering experiments.The survival rate of artificial gastric juice was 93.92 %,the tolerance of bile salt was 16.93 %,the hydrophobic capacity was 41.43 %,and the cholesterol removal rate was 58.22 %.Relative to other strains,No.1 strain has a strong bile salt hydrolase activity.The strain was identified as Lactobacillus casei by morphological analysis and carbohydrate fermentation experiments and named as Lactobacillus casei YBJ02(2)Lactobacillus casei YBJ02 strain was found to be non-toxic to mice by high fat mouse animal model test.Different concentrations of bacteria had certain inhibitory effect on the increase of blood lipid level in mice.Especially high concentration of bacteria can reduce the cholesterol,triglycerides,low density lipoprotein content,but no significant impact on high density lipoprotein of the body.Through the determination of cholesterol in mice liver,cholesterol and water content in the feces of mice,we can see that high fat diet can increase fat accumulation in the liver,excess cholesterol absorbed by mice is discharged with feces,and high concentration of bacteria can effectively increase the amount of cholesterol with the excretion of feces.High fat diet caused feces dry of mice,lactic acid bacteria can increase the water content of mice feces.(3)The gene that affected mouse obesity was determined by the experimental results in mice.It was found that the expression of PPAR?,CEBP / ?,SREBP-1c and FAS could improve because of the high-fat diet in kidney fat.Different concentrations of bacteria could also decrease there impression,especially the high concentration of bacteria could suppress the expression of PPAR?,CEBP / ? and SREBP-1c,but the expression of FAS was not significantly inhibited.In the liver,PPAR?,FAS expression was low,had no significant difference.The expression of CEBP / ? and SREBP-1c in mouse liver was further detected by western blot.The expression of CEBP / ? was very low and could not be detected.Although the protein expression of SREBP-1c was not very high,but there was significant difference in each group,high-fat diet caused the expression of SREBP-1c in the liver increased,feeding bacteria group can inhibit its expression,and high concentration bacteria liquid group had a better inhibitory effect.