Study On The Efficacy And Mechanism Of Compound Lactobacillus Powder In Improving Mouse Allergy

Allergic disease is a common disease that seriously threatens human health,especially in the early childhood.In this study,we will select Lactobacillus fermentans RA3 and Lactobacillus plantarum A5,B2 and C4 with independent intellectual property rights from Xinjiang traditional sour horse milk,and select the compound Lactobacillus with the best anti allergy potential.By optimizing the combination of cold shock conditions and freeze-drying protectors,the survival rate of freeze-drying was improved,and the composite Lactobacillus powder with high activity was prepared.In order to reveal the effect and mechanism of complex Lactobacillus powder in improving mouse allergy,the effect of complex Lactobacillus powder on improving mouse allergy and the change of intestinal microflora structure were studied.The main results are as follows:1.Screening and proportion determination of compound Lactobacillus.Four kinds of lactic acid bacteria were screened from Xinjiang sour horse milk,and they were mixed into different compound lactic acid bacteria in the ratio of 1:1.Then the compound Lactobacillus were used to the performance test with potential antiallergic effect.The results showed that the diameter of bacteriostatic circle,acid producing ability,autolysis,proteolysis ability and aminopeptidase activity were 23.87 mm,1.29,34.27%,3.117 U/mL and 10.612 U/mL.They were significantly higher than that of other complex bacteria(P<0.05),which had potential anti allergy characteristics.Therefore,this complex bacteria,which was mixed from the lactic acid bacteria RA3 and C4,was selected for subsequent tests.2.Preparation of complex Lactobacillus powder.With Lactobacillus acidophilus(L.acidophilus)as the model strain,cold shock pretreatment was carried out before freeze-drying,combined with the method of adding complex freeze-drying protectors during freeze-drying,the best treatment conditions for improving the survival rate of freeze-drying were obtained:collecting the bacteria at 10 hours of culture,cold shock treatment at 8°C and 15h.Combined with the composite freeze-drying protectant,the survival rate of the strain after freeze-drying can be increased to 96.64%.By using this method,the complex Lactobacillus powder with high activity of RA3 and C4 can be prepared.3.Study on the effect of complex Lactobacillus powder on mice allergy.Application of compound Lactobacillus powder in the treatment of allergic mice.The results showed that there were no abnormal changes in body weight,physical signs,behavior and organ coefficient of mice fed with complex Lactobacillus powder;The spleen and thymus coefficients of mice in the low-dose bacterial powder group,the medium-dose bacterial powder group and the high-dose bacterial powder group were significantly higher than those in the human allergic group(P<0.01),and the total Ig E(T-Ig E)level of mice in the high-dose bacterial powder group was 351.8 ng/mL,it was significantly lower than that of human allergic group(P<0.01);IFN-?was 1119.5 pg/mL,TNF-?was 639.0 pg/mL,IL-6 was 54.16 pg/mL and IL-12 was 11.05 pg/mL in low-dose bacterial powder group,they were significantly higher than those in the human allergic group(P<0.01);IL-10 was 53.28 pg/mL in high-dose bacterial powder group,it was significantly higher than that of the human allergic group(P<0.01);the high-dose bacterial powder group could increase the expression of IL-6 mRNA in the spleen of mice(P<0.05);the low-dose bacterial powder group,the medium-dose bacterial powder group and the high-dose bacterial powder group could increase the number of lymphocytes in the spleen tissue and restore the normal tissue structure.Therefore,the compound Lactobacillus can improve the immune function of mice and ameliorate the allergic effect of mice,the high dose(1×10~8 CFU/mL)is the most effective.4.Effect of complex Lactobacillus powder on the structure of intestinal flora in mice.Compared with the allergenic group,in the low,medium and high dose group,with the increase of the amount of complex Lactobacillus powder,the phylum of sclerenchyma decreased in turn,while Bacteroidetes increased gradually.In the high dose group,the phylum of Proteus almost disappeared completely.Among them,Bacteroides has the ability to inhibit the growth of allergens and kill pathogenic bacteria,while Proteus has the potential to cause allergy,which is a pathogenic flora.In conclusion,the high activity complex Lactobacillus powder prepared in this experiment can enhance the immune function of mice,regulate the structure of intestinal flora of mice,and improve the allergic symptoms of mice.It has theoretical significance and practical application value for the development of microecological agents with hypoallergenic effect.