| The antibiotics can improve the economic efficiency of the livestock industry, but it also carries serious harms to human beings with the bacterial resistance and waste of medical resources.The lactobacillusused as probiotics,can effectively improve animal production performance and immune function, and it is hopeful to replace antibiotics because of the advantages of the innocuity, harmlessnes and non-polluting to environment.The bacteria have a special presence status, which is "Viable But Non-Culturable"(VBNC),and it makes the researchers better understand the bacteria. At present,the studies on the VBNC are commonly found in terms of pathogens, while few studies about VBNC state of Lactobacillus.But now more and more researchers start to concern widely and study deeply the Lactobacillus with VBNC state.The influence of Lactobacillus with VBNC state on immune functions of mice was studied by using Lactobacillus mutants with VBNC state and normal Lactobacillus,with PBS as the control group.There were three groups: ZTVBNC group, Z group and PBS group in this study.The mice(4 weeks) were fed with different Lactobacillus,and it was about 1×109cfu for each mouse every time.The mouse blood were collected and centrifuged, and sera were collected weekly.The immune indexes were detected by ELISA, including IL-10, TNF-α, IgG and sIgA.The lymphocyte transformation test was performed by mouse spleen.And the phagocytic activity of leucocytes was measured by anticoagulant.The results showed that sIgA content of serum increased, anti-inflammatory cytokine IL-10 secretion was promoted and anti-inflammatory cytokines TNF-αcontent was down-regulated in Lactobacillus mutant group.In addition, the phagocytic activity of leucocytes and lymphocytes proliferation assay have also been enhanced.The weight change curve displayed that Lactobacillus mutants and normal Lactobacillusboth could promote the weight of mice.The results of all the immune indexes showed that the comprehensive immune effects of ZTVBNC group were better than Z group and PBS group.In summary, ZTVBNC could improve production performance and immune function of mice. These results will provide the theoretical basis and new methods for development and preparation of new probiotics. |
