Screening And Functional Study Of Lactic Acid Bacteria In Fermented Foods That Can Prevent And Treat Metabolic Diseases

Metabolic disease is a kind of chronic physiological disease caused by the disorder of nutrient metabolism.Intestinal microorganisms,especially the Lactic acid bacteria(LAB)can affect the metabolism of the host by their own metabolism.Through the directional function selection,we unearthed the LAB which has the function of participating in the metabolism of potentially dangerous substances,which can effectively control the occurrence and development of metabolic diseases.Compared with the traditional medicine which can treat metabolic disease,LAB have the characteristics of wide antimicrobial spectrum,high stability and good safety,which make LAB have immensely applied prospects.In this study,we used fermentation food collected from Heilongjiang province which has special natural environment and traditional fermented food as materials and screened out 60 strains of LAB through separation and purification of useing MRS media.We established a screening library of LAB which were identified by physiological and biochemical identification.In the screening of LAB on different metabolic diseases,through ?-glucosaccharase inhibition test,cholesterol absorption test,the degradation of inosine and guanosine test,we established three screening model which can regulate blood sugar level,decrease serum uric acid,and reduce blood fat in vitro respectively.After that,we screened out 8 candidate strains which have the function of preventing metabolic diseases.Animal models were established in terms of type?diabetes,Hypercholesterolemia and Hyperuricemia for secondary screening from eight strains by the determination of fasting blood-glucose,blood-cholesterol and blood uric acid.The results show that blood-cholesterol content of S1401 group decreased by 14.23% and 14.06% on prevention and treatment of hypercholesterolemia respectively,which is significantly different compared with other strains(p<0.05).In addition strains S0701 and S1001 were capable in prevention of increasing blood-glucose compared with positive control(p<0.05),and the S1402 result in decline of uric acid on prevention and treatment which is account for 8.93% and 30.58% respectively.Aimed at the affects of S1402 on gut microorganism,high throughput sequencing method was carried out for analyzing intestinal microbial diversity.The results show that S1402 can remarkably influence abundance of three gut microbial species in hyperuricemia group.Finally,genetic and physiological and biochemical identification of S1402 was carried out by 16 Sr DNA sequencing and APi50 CH respectively,then a blast with known sequences prove that S1402 is Lactobacillus rhamnosus.A good strains evaluation following animal acute toxicity test and histology sections both verify the security of S1402.Furthermore,the S1402 was capable in inhibition of Escherichia.coli and Staphylococcus aureus by antimicrobial test.The test of antibiotic sensitivity,Hydrophobicity,acid resistance and bile salt-resistance prove that S1402 can adapt to the special environment in the gut.The results apply theory support for the strains S1402 on application research.