枯草芽孢杆菌RZ001对乳鼠肠道发育、肠道菌群和Wnt信号通路相关基因表达的影响

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(1×107 CFU/d),对照组...

Effects of Bacillus subtilis RZ001 on Intestinal Development,Intestinal Microbiota and Expression of Wnt Signaling Pathway Related Genes of Suckling Mice

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.