流感病毒感染对小鼠肠道菌群的影响及桑叶的调节作用

The influence of influenza virus infection on the mice intestinal flora and the regulation action of mulberry leaf during the treatment of influenza in mice

目的探讨流感病毒对肠道菌群的影响以及桑叶提取物在治疗小鼠流感时对肠道菌群的调节作用。方法将36只小鼠随机分为4组,正常对照组滴鼻生理盐水,其余以流感病毒鼠肺适应株FM1滴鼻3 d,建立流感小鼠模型后,正常对照组和病毒对照组灌胃生理盐水,另2组分别以高剂量(500 mg/kg)和低剂量(100 mg/kg)灌胃桑叶提取物,连续5 d。每天检测小鼠体重,并于病毒感染前、感染后及灌胃处理后3次无菌收集小鼠粪便,培养并计数小鼠粪便中肠杆菌、肠球菌、乳酸杆菌和双歧杆菌。结果小鼠在感染病毒后体重明显降低,桑叶提取物治疗后体重降低的趋势有所减缓。小鼠肠道菌群在感染流感后有明显的变化,但桑叶提取物治疗后肠道菌群的恢复不明显。结论流感病毒感染能引起小鼠肠道菌群的失调,桑叶不显示调节肠道菌群的效果,表明其对流感的治疗不通过调节肠道菌群平衡来发挥作用。

Objective To discuss the influence of influenza virus on the intestinal flora in mice and the regulation of mulberry leaf extract （MLE） in the infected mice. Methods 36 mice were randomly divided into four groups. The mice in influenza virus group, MLE high dose group and low dose group were inoculated influenza virus mouse lung-adapted strain FM1 by nasal inhalation while the normal group raice were inoculated with normal saline （NS） for 3 days. Then the mice were intragastric garaged （ig） with MLE （high dose： 500 mg/kg, low dose ： 100 mg/kg） or NS in normal group and virus control group for 5 days respectively. Weighed the mice every day, col- lected feces of the mice before viral infection, post-infection and after cured with MLE or NS. The enteric bacilli, enterococcus, lactoba- cillus and bifidobaeterium in the feces were counted and analyzed after culture. Results The body weight of the mice in virus control group decreased distinctly, and the MLE slowed down the trend of the decrease. The intestinal flora changed obviously after influenza virus infection, but MLE did not show any regulatory effect on it. Conclusion Infection of influenza virus will alter the intestinal flora, and MLE hasn＇ t ability to recover the balance of intestinal flora, so the therapeutical effect of MLE on influenza A virus should be due to other mechanisms.