哺乳人溶菌酶转基因乳汁提高仔鼠肠道健康水平

Consumption of human lysozyme transgenic milk improved intestinal health of mouse pups

为探究富含人溶菌酶的转基因乳汁对仔鼠肠道健康影响,以转基因母鼠代养普通仔鼠(试验组)和普通母鼠代养普通仔鼠(对照组)为研究对象,进行仔鼠肠道菌群数量检测、肠道形态观测和大肠杆菌攻毒腹泻模型等试验,采样和检测时间为第3、11、21、30天(D3,D11,D21,D30)。结果表明:1)试验组的仔鼠肠道菌群总菌数在D11、D21显著性低于对照组(P<0.05);试验组乳酸菌在D21显著性高于对照组(P<0.05),双歧杆菌在D11和D30均显著性高于对照组(P<0.05);试验组大肠杆菌在D21显著性低于对照组(P<0.05),链球菌在D11极显著性低于对照组(P<0.01)且在D21显著性低于对照组(P<0.05),肠球菌在D11极显著性低于对照组(P<0.01),梭菌在D11显著性低于对照组(P<0.05);2)试验组仔鼠肠道内容物溶菌酶活性为1 803±93 U/μg,对照组仅为73±23U/μg;试验组仔鼠半固体粪便在大肠近/中端形成(9/10),而对照组仔鼠半固体粪便在大肠中/末端形成(8/10);3)大肠杆菌攻毒腹泻模型中,试验组无仔鼠死亡,而对照组于攻毒144h后死亡9只(死亡率60%)。因此,转基因鼠乳汁来源的高浓度重组人溶菌酶,能在仔鼠小肠中保持较高的活性,显著提高其内容物中的有益菌数量和降低有害菌数量,促进大肠半固体粪便形成,从而为攻毒后的小鼠腹泻模型提供保护作用。

The aim of this study was to investigate the effect of human lysozyme transgenic milk on intestinal health.The mouse pups were nursed randomly by transgenic mother mice（PC group）and non-transgenic mother mice（NC group）,and the experiments as follows were performed on day 3,11,21,30（D3,D11,D21 and D30）：the number of intestinal bacterial flora was counted,the fecal morphology of mouse pups in different groups was observed,and the mice were induced to diarrhea models by injection of Escherichia coli.The results showed that：1）The total bacteria in PC group was significantly lower than that in NC group at D11 and D21（P 〈0.05）;The quantity of beneficial bacteria Lactobacillus spp.in PC group was significantly higher than that in NC group at D21（P 〈0.05）,and the Bifidobacterium spp.was also significantly higher than that in NC group at D11 and D30（P〈0.05）;The quantity of harmful bacteria E.coli in PC group was significantly lower than that in NC group at D21（P〈0.05）,the Streptococcus was very significantly lower than that in NC group at D11（P〈0.01）and significantly lower than that in NC group at D21（P〈0.05）,the Enterococcus was very significantly lower than that in NC group at D11（P〈0.01）,and theClostridium was significantly lower than that in NC group at D11（P〈0.05）.2）The lysozyme activities of small intestine contents were 1803±93 U/μg in PC group,while was only 73±23 U/μg in NC group;the semisolid stools were formed in the proximal/middle of colonin in PC group（9/10）,whereas in the middle/end of large intestine in NC group（8/10）.3）The mortality rate of diarrhea mice model in NC group was 60%,while in PC group was 0.Inconclusion,recombinant human lysozyme of the transgenic mice kept high activity in the small intestine of mouse pups,which significantly increased the number of beneficial bacteria,reduced the number of harmful bacteria in the intestine,promoted semisolid stool formation and provided protection for the mouse diarrhea model.