羊源解淀粉芽孢杆菌fsznc-06对小鼠生长和免疫功能的影响

Effects of Bacillus amyloliquefaciens fsznc⁃06 Isolated from Goats on Growth and Immune Function of Mice

本试验旨在探究羊源解淀粉芽孢杆菌fsznc-06对小鼠生长和免疫功能的影响。选取36只健康的小鼠,随机分为3组,每组3个重复,每个重复4只。低剂量组(JD1组)和高剂量组(JD2组)每2 d灌胃1次浓度分别为1×10^8和1×10^10CFU/mL的羊源解淀粉芽孢杆菌fsznc-06菌悬液,灌胃量为0. 3 mL/只;对照组(DZ组)每2 d灌胃1次0. 9%生理盐水,灌胃量为0.3 mL/只。试验期为28 d。测定各组小鼠生长性能、血清生化指标、生长和免疫相关基因表达量以及肠道菌群多样性。结果表明:1)与DZ组相比,JD1组第7、14、21和28天体增重显著或极显著提高(P<0.05或P<0.01),JD2组第7和14天体增重显著或极显著提高(P<0.05或P<0.01)。与DZ组相比,JD1组第1~7天、第8~14天、第15~21天和第22~28天料重比显著或极显著降低(P<0.05或P<0.01),JD2组第1~7天、第15~21天和第22~28天料重比显著或极显著降低(P<0.05或P<0.01)。2)与DZ组相比,JD1组心脏、小肠指数以及JD2组心脏、脾脏、胸腺、大肠指数显著或极显著提高(P <0. 05或P <0. 01), JD1组血清总超氧化物歧化酶(T-SOD)、碱性磷酸酶(AKP)活性以及JD2组血清AKP活性显著或极显著提高(P<0.05或P<0.01)。3)与DZ组相比,JD1组脾脏胰岛素样生长因子-1(IGF-1)基因表达量和JD2组脾脏IGF-1和干扰素α11(IFNα11)基因表达量显著或极显著提高(P<0.05或P<0.01),JD1组脾脏白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)和JD2组IL-1β、白细胞介素-6(IL-6)、一氧化氮合酶(iNOS)和TNF-α基因表达量显著或极显著降低(P<0.05或P<0.01)。4)与DZ组相比,JD1和JD2组小鼠肠道菌群多样性和双歧杆菌属的相对丰度均明显提高,优势物种相对丰度也明显提高。由此可见,羊源解淀粉芽孢杆菌fsznc-06可促进小鼠生长,提高免疫功能,且JD2组效果相对更佳。

This experiment was conducted to investigate the effects of Bacillus amyloliquefaciens fsznc⁃06 iso⁃lated from goats on growth and immune function of mice.Thirty⁃six healthy mice were randomly divided into 3 groups with 3 replicates per group and 4 mice per replicate.Mice in low dose group(JD1 group)and high dose group(JD2 group)were given 1×10^8 and 1×10^10 CFU/mL Bacillus amyloliquefaciens fsznc⁃06 isolated from goats by gavage once every 2 days,and the gavage volume was 0.3 mL per mouse;mice in the control group(DZ group)were given 0.9%normal saline by gavage once every 2 days,and the gavage volume was 0.3 mL per mouse.The experiment lasted for 28 days.The growth performance,serum biochemical index,ex⁃pression levels of growth and immune related genes and intestinal flora diversity of mice were measured.The results showed as follows:1)compared with the DZ group,the body weight gain on days 7,14,21 and 28 of JD1 group was significantly increased(P<0.05 or P<0.01),and the body weight gain on days 7 and 14 of JD2 group was significantly increased(P<0.05 or P<0.01).Compared with the DZ group,the feed to gain ratio on days 1 to 7,days 8 to 14,days 15 to 21 and days 22 to 28 of JD1 group was significantly decreased(P<0.05 or P<0.01),and the feed to gain ratio on days 1 to 7,days 15 to 21 and days 22 to 28 of JD2 group was significantly decreased(P<0.05 or P<0.01).2)Compared with the DZ group,the indexes of heart and small intestine of JD1 group and indexes of heart,spleen,thymus and large intestine of JD2 group were signifi⁃cantly increased(P<0.05 or P<0.01),the activities of total superoxide dismutase(T⁃SOD),alkaline phos⁃phatase(AKP)in serum of JD1 group and serum AKP activity of JD2 group were significantly increased(P<0.05 or P<0.01).3)Compared with the DZ group,the spleen insulin⁃like growth factor⁃1(IGF⁃1)gene ex⁃pression level of JD1 group and expression levels of IGF⁃1 and interferon alpha 11(IFNα11)in spleen of JD2 group were significantly increased(P<0.05 or P<0.01),and the expression levels of interleukin⁃1β(IL⁃1β),tumor necrosis factor⁃α(TNF⁃α)in spleen of JD1 group and expression levels of IL⁃1β,interleukin⁃6(IL⁃6),nitric oxide synthase(iNOS)and TNF⁃αin spleen of JD2 group were significantly decreased(P<0.05 or P<0.01).4)Compared with the DZ group,the intestinal flora diversity and relative abundance of Bifidobacteria of JD1 and JD2 groups were increased,and the relative abundance of dominant species was also increased.In conclusion,Bacillus amyloliquefaciens fsznc⁃06 isolated from goats can promote the growth and improve the immune funtion of mice,and JD2 group has a relatively better effect.