枯草芽孢杆菌可提高兔的免疫力和抗病性
Title：
Bacillus subtilis Improves Immunity and Disease Resistance in Rabbits
Abstract：
Probiotics such as Lactobacillus and Bifidobacterium have been successfully used to promote growth and prevent diseases. Previous reports have demonstrated that Bacillus subtilis (B. subtilis) was a potential probiotic for animals. In this research, 180 B. subtilis were isolated from the soil, identified, and investigated in vitro. Furthermore, five B. subtilis were selected and mixed to investigate their effect on growth performance, immune response, intestine microbiota, and disease resistance in rabbits. Rabbits with a diet of 106 CFU g−1 mixed B. subtilis exhibited the best growth performance and higher serum IgG and IgA than controls (P < 0.05). Moreover, dairy with B. subtilis can promote the balance of intestinal flora. The major proinflammatory factor and β-defensin were upregulated compared with the controls. After 7 weeks of feeding, the survival rate of the rabbits fed with B. subtilis was significantly higher than those in the control groups postinfected with Escherichia coli. At the same time, this study detected higher expression of β-defensin and reduced bacteria contents of the heart and cecal contents from the diet mixed with B. subtilis compared with the control groups. In conclusion, dietary supplementation with B. subtilis for rabbits could improve growth performance, intestinal homeostasis, and immune organ index and enhance innate immune response as well as disease resistance. These findings showed that the induction of β-defensin by B. subtilis might be an interesting new therapeutic strategy to strengthen innate defense mechanisms.
All Authors：
Mengjiao Guo, Fahao Wu, Guangen Hao, Qin Qi, Rong Li, Ning Li, Liangmeng Wei, Tongjie Chai
First Authors：
Mengjiao Guo
Correspondence：
Liangmeng Wei, Tongjie Chai
内容要点：
1、动物研究表明，枯草芽孢杆菌是一种潜在的益生菌；
2、从土壤中分离鉴定180种枯草芽孢杆菌，筛选5种菌混合进行体外研究，探讨其对兔生长性能、免疫反应、肠道菌群与抗病性的影响；
3、 饮食中含有枯草芽孢杆菌混合菌株的兔表现出相对对照组兔更好的生长情况，且有着更高的血清IgG及IgA；
4、含有枯草芽孢杆菌的乳制品可促进肠道菌群的平衡，可上调主要的促炎因子及β-防御素；
5、相对与对照组兔，喂食枯草芽孢杆菌的兔在感染大肠杆菌后存活率更高。