摘要
本试验旨在研究枯草芽孢杆菌RZ001的早期定植对乳鼠早期生长、肠道发育、肠道菌群和Wnt信号通路相关基因表达的影响。选择4窝数量相同的新出生的C57BL/6小鼠乳鼠,分为2个组(对照组和试验组),每组2个重复。从出生后第2天开始,试验组乳鼠连续14 d灌胃10μL枯草芽孢杆菌RZ001(1×10^7 CFU/d),对照组乳鼠连续14 d灌胃10μL磷酸盐缓冲液(PBS)。结果表明:1)与对照组相比,试验组的乳鼠从出生后第2天到第8天体重显著或极显著增加(P<0.05或P<0.01),脾脏、肾脏、胸腺重量和指数显著或极显著增加(P<0.05或P<0.01),但肝脏重量和指数无显著差异(P>0.05)。2)与对照组相比,试验组的小肠绒毛密度、绒毛长度和绒毛长度/隐窝深度显著或极显著增加(P<0.05或P<0.01),隐窝深度极显著降低(P<0.01)。3)与对照组相比,试验组的小肠杯状细胞的数量显著增加(P<0.05),小肠中黏蛋白2(MUC2)的mRNA相对表达量和MUC2含量均显著增加(P<0.05)。4)与对照组相比,试验组的小肠中闭锁小带蛋白-1(ZO-1)、闭锁蛋白(Ocln)、封闭蛋白-3(Cldn-3)的mRNA相对表达量均极显著增加(P<0.01)。5)与对照组相比,试验组的小肠中Wnt3、卷曲受体蛋白7(Fzd7)、低密度脂蛋白受体相关蛋白5(Lrp5)、糖原合成激酶-3β(Gsk-3β)、Ctnnb1、细胞性骨髓细胞瘤病毒癌基因(C-myc)、轴蛋白抑制蛋白2(Axin2)、无张力同系物1(Atoh1)、富含亮氨酸重复序列的G蛋白偶联受体5(Lgr5)和Ki67的mRNA相对表达量显著或极显著升高(P<0.05或P<0.01),但低密度脂蛋白受体相关蛋白6(Lrp6)的mRNA相对表达量显著降低(P<0.05);同时,试验组的小肠中β-连环蛋白(β-catenin)蛋白相对表达量显著升高(P<0.05)。6)门水平上,与对照组相比,试验组的盲肠中拟杆菌门的相对丰度显著增加(P<0.05),而厚壁菌门的相对丰度显著降低(P<0.05)。属水平上,与对照组相比,试验组的盲肠中双歧杆菌属的相对丰度极显著增加(P<0.01),而产气荚膜梭菌的相对丰度极显著降低(P<0.01)。由此可见,早期应用枯草芽孢杆菌RZ001能够促进乳鼠生长,改善肠道形态,促进肠道屏障功能成熟,从而促进早期肠道发育。早期应用枯草芽孢杆菌RZ001还能够激活Wnt信号通路,降低肠道致病菌产气荚膜梭菌的相对丰度,增加肠道益生菌双歧杆菌属的相对丰度。
This experiment was conducted to investigate the effects of early colonization of Bacillus subtilis RZ001 on growth intestinal development,intestinal microbiota and expression of Wnt signaling pathway related genes of suckling mice.Four new born C57BL/6 mice with the same number of litters were selected and divided into two groups(experimental group and control group)with two replicates in each group.From the second day after birth,the suckling mice in the experimental group were given 10μL Bacillus subtilis RZ001(1×10^7 CFU/d)by gavage for 14 continuous days,and the suckling mice in the control group were given 10μL phosphate buffer saline by gavage for 14 continuous days.The results showed as follows:1)compared with the control group,the body weight of suckling mice from day 2 to day 8 after birth of experimental group was significantly increased(P<0.05 or P<0.01),the weight and index of spleen,kidney and thymus were significantly increased(P<0.05 or P<0.01),but the weight and index of liver were no significant difference(P>0.05).2)Compared with the control group,the villus density,villus length and villus length/crypt depth in small intestine of experimental group were significantly increased(P<0.05 or P<0.01),and the crypt depth was significantly decreased(P<0.05).3)Compared with the control group,the number of goblet cells in small intestine of experimental group was significantly increased(P<0.05),and the mucin 2(MUC2)mRNA relative expression level and MUC2 content in small intestine were significantly increased(P<0.05).4)Compared with the control group,the mRNA relative expression levels of zonula occluden-1(ZO-1),occludin(Ocln)and claudin-3(Cldn-3)in small intestine of experimental group were significantly increased(P<0.01).5)Compared with the control group,the mRNA relative expression levels of Wnt3,frizzled 7(Fzd7),low density lipoprotein receptor related protein 5(Lrp5),glycogen synthase kinase-3β(Gsk-3β),Ctnnb1,cellular-myelocytomatosis viral oncogene(C-myc),axin inhibitor 2(Axin2),atonal homolog 1(Atoh1),leucine rich repeat containing G protein-coupled receptor 5(Lgr5)and Ki67 in small intestine of experimental group were significantly increased(P<0.05 or P<0.01),but the mRNA relative expression level of low density lipoprotein receptor related protein 6(Lrp6)was significantly decreased(P<0.05);meanwhile,the protein relative expression level ofβ-catenin in small intestine of experimental group was significantly increased(P<0.05).6)At the phylum level,compared with the control group,the relative abundance of Bacteroidetes in cecum of experimental group was significantly increased(P<0.05),while the relative abundance of Firmicutes was significantly decreased(P<0.05).At the genus level,compared with the control group,the relative abundance of Bifidobacterium in cecum of experimental group was significantly increased(P<0.05),while the relative abundance of Clostridium perfringens was significantly decreased(P<0.05).It is concluded that early application of Bacillus subtilis RZ001 can promote the growth of suckling mice,improve intestinal morphology,promote the maturation of intestinal barrier function,and thus promote early intestinal development.In addition,early application of Bacillus subtilis RZ001 can activate Wnt signaling pathway,reduce the relative abundance of enteropathogenic Clostridium perfringens,and increase the relative abundance of intestinal probiotics Bifidobacterium.
作者
郭聪聪
李艳茹
耿萌
盖塞伦
张滕勋
齐威
李中媛
宋亚囝
罗学刚
张同存
王楠
GUO Congcong;LI Yanru;GENG Meng;GAI Sailun;ZHANG Tengxun;QI Wei;LI Zhongyuan;SONG Yajian;LUO Xuegang;ZHANG Tongcun;WANG Nan(Key Laboratory of Industrial Fermentation Microbiology,Ministry of Education,College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China;Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control,Tianjin 300457,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2021年第1期506-518,共13页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家重点研发计划(2017YFD04000304)
天津市自然科学基金(17JCZDJC33600)
天津市教委创新研究团队(TD13-5015)。
关键词
枯草芽孢杆菌
乳鼠
肠道发育
WNT信号通路
肠道菌群
Bacillus subtilis
suckling mice
intestinal development
Wnt signaling pathway
intestinal microbiota