| Aflatoxin is derived from dihydrofuran coumarin produced by both Aspergillus flavus and Aspergillus parasitic,and be confirmed as class I carcinogens by International Agency for Research on Cancer（IARC）.Aflatoxin exposure is associated with but not limit,such as malnutrition,stunted growth,immunosuppression and cancer in vivo.In particular,aflatoxin cause serious impact on organs such as liver,kidney and intestinal tract.Lactobacillus rhamnosus is a gram-positive bacteria,which could regulate intestinal microecology,protect viscera,improve immunity and prevent cancer.Therefore,the purpose of this studyr is focus on the preventive ability of Lactobacillus rhamnosus on the animal model of chronic AFB1 poisoning with different supplement methods on the animal model of chronic AFB1 poisoning.The possible causes were discussed from the point of view of intestinal tract,and the intake and form of Lactobacillus rhamnoides in food were determined,aimed to provide theoretical and experimental basis for AFB1 metabolism by probiotics in human and animal bodies.The present study,4-week-old SD rats and BALB/C mouse were used as research objects.On the basis of pre-experiment and literature,the addition amount of AFB1 with diet was set as 50μg/kg.Three kinds of Lactobacillus rhamnosus were prepared:1)living liquid（After the culture medium was centrifuged and the supernatant was discarded,then re-suspended with sterile saline）,2)heat inactivated bacteria solution（15min heated at 121℃）,3)and the supernatant of fermentation（the supernatant was taken after centrifugation of the culture medium）.High,middle and low doses of Lactobacillus rhamnoides were selected to explore the effects of Lactobacillus rhamnoides on target organ injury prevention,immunosuppression prevention and intestinal flora regulation in rats and mice.The best intake mode and the dose of Lactobacillus rhamnoides were detected by the experimental.This study showed all of the three treatments of Lactobacillus rhamnosus had strong AFB1 adsorption abality,and the living Lactobacillus rhamnose solution of1010 cfu/m L showed the strongest adsorption capacity.With intragastric administration of 1010cfu/m L live Lactobacillus rhamnosus solution,the body weight of the experimental animals increased significantly,the growth and developmentwere promoted,the liver and kidney index were decreased,the related serum biochemical TP,ALB,ALT,AST,ALP,BUN,TC and TG secretion levels were improved,the AFB1 content in the liver and kidney of the related target organs were reduced,the related pathological symptoms were ameliorated,and the target organ damage caused by AFB1 were effectively inhibted.The thymus index of rats increased,the levels of serum immunoglobulin Ig A,Ig G and Ig M increased,the level of serum cellular immune factor IL-4decreased,IL-2 increased and TNF-αincreased,which enhanced humoral immunity and cellular immunity.Live Lactobacillus rhamnosus solution supplement decreased the secretion level of DAO and D-lactic acid in serum,increased the secretion level of colonic SIg A,and effectively prevented the injury of ileum and duodenum caused by AFB1.Protected intestinal mucosal barrier,improved intestinal mucosal immune function and the ability of intestinal barrier.Lactobacillus rhamnosus effectively increased the Alpha diversity and Beta diversity index,diversity and richness of mouse intestinal flora in mouse.In terms of species composition,Lactobacillus rhamnoides up-regulated the Firmicutes abundance of Bacteroides,and down-regulated the abundance of Actinobacteria and actinomycetes at the gate level;at the genus level,up-regulated the abundance of Lachnospiraceae NK4A136 group and Roseburia,and down-regulated the abundance of Staphylococcus.Lactobacillus rhamnosus effectively promoted the proliferation of intestinal beneficial bacteria,inhibited pathogenic bacteria,adjusted the proportion of bacteria,and promoted the health of intestinal microecology of mouse.The results of this study show that the best way to prevent target organ damage,immunosuppression and intestinal microecological imbalances caused by AFB1 is to take live Lactobacillus rhamnosus and ensure that the number of live bacteria ingested is not less than 10billion(1010 cfu/mL). |
