极低蛋白日粮补充不同形式氮营养素对生长猪回肠食糜菌群、代谢产物和屏障功能的影响  

Effects of extremely-low-protein diets supplemented with different nitrogen source on ileal microbial communities,metabolites profiles and barrier function of growing pigs

作　　者：刘壮[1] 慕春龙[1] 彭宇[1] 彭燮[2] 车炼强[2] 朱伟云[1] LIU Zhuang;MU Chunlong;PENG Yu;PENG Xie;CHE Lianqiang;ZHU Weiyun(National Center for International Research on Animal Gut Nutrition/Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health/Laboratory of Gastrointestinal Microbiology of College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,China;Institute of Animal Nutrition,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]南京农业大学国家动物消化道营养国际联合研究中心/江苏省消化道营养与动物健康重点实验室/动物科技学院消化道微生物研究室,江苏南京210095 [2]四川农业大学动物营养研究所,四川成都611130

出　　处：《南京农业大学学报》2019年第3期526-534,共9页Journal of Nanjing Agricultural University

基　　金：国家973计划项目(2013CB127300);国家自然科学基金重点项目(31430082)

摘　　要：[目的]本试验旨在研究极低蛋白(ELP)日粮下,补充不同形式氮营养素(氨基酸或酪蛋白)对生长猪回肠微生物、代谢产物和屏障功能的影响。[方法]试验选用80头PIC阉公猪(体质量约15.57 kg,48日龄),随机分为4组:中等蛋白组(MP)、低蛋白组(LP)、极低蛋白+氨基酸组(ELP-AA)和极低蛋白+酪蛋白组(ELP-CAS),日粮粗蛋白(CP)水平分别为17%、15%、13%和13%。每个处理5个重复,每个重复4头仔猪。试验期28 d。MP和LP两组添加必需氨基酸(AA),ELP-AA组添加非必需AA以达到LP组日粮水平,ELP-CAS组使用3%酪蛋白部分替代ELP-AA组的单体AA,使其满足营养需要。于第29天每个重复挑选1头接近栏平均体质量的猪屠宰,采集回肠食糜和肠道组织样品,用于各项指标测定。[结果]与MP组相比,ELP-AA组回肠食糜中双歧杆菌属(Bifidobacterium)、乳酸杆菌属(Lactobacillus)和消化链球菌属(Peptostreptococcus)的数量显著降低(P<0.05),短链脂肪酸、氨态氮和生物胺的含量均显著下降(P<0.05),而补充酪蛋白后,乙酸、丁酸、氨态氮、腐胺和精胺的含量得到显著恢复(P<0.05)。基因表达方面,与LP组相比,ELP-AA组部分肠道屏障功能相关基因(MUC-1、MUC-2和Occludin)的表达量均显著下调(P<0.05),而MUC-1和Occludin的表达量在ELP-CAS组和MP或LP组之间无显著差异(P>0.05)。相关性分析结果表明,Lactobacillus数量与丁酸和生物胺含量、MUC-1、MUC-2和Occludin基因表达量显著正相关。[结论]饲喂极低蛋白日粮补充单体氨基酸对回肠微生物数量、代谢以及肠道组织屏障均产生不利影响,而补充酪蛋白能部分改善回肠有益微生物的生长并恢复部分肠道屏障相关基因的表达,提示在极低蛋白质水平下,补充酪蛋白对维持机体正常氮利用、肠道微生物生长代谢和肠道屏障功能具有重要作用。[Objectives]This study aimed to study the effects of extremely-low-protein(ELP)diet supplemented with different nitrogen source(AA or casein)on intestinal bacteria and barrier function-related gene expressions in the ileum of growing pigs.[Methods]Eighty barrows(PIC,initial body mass(15.57±0.13)kg,48 days of age),housed in 4 pigs per pen with 5 pens per treatment,were randomly assigned to four dietary treatments:medium protein(MP),low protein(LP),extremely-low-protein plus amino acids(ELP-AA)and ELP-casein(ELP-CAS),and the dietary cruld protein(CP)levels are 17%,15%,13%and 13%,respectively.Crystalline AA was added to meet the essential AA requirement of pigs.After 28 days feeding,one pig from each pen(n=5 per treatment)was randomly selected and slaughtered for sampling of ileal digesta and tissue.[Results]Compared with MP group,the counts of Bifidobacterium,Lactobacillus and Peptostreptococcus in the ileal digesta significantly decreased in ELP-AA group(P<0.05),while no significant difference was observed in ELP-CAS group(P>0.05).Compared with MP group,the content of short-chain fatty acids,ammonia and biogenic amines significantly decreased in ELP-AA group(P<0.05),while the content of acetate,butyrate,ammonia,putrescine and spermine increased after adding casein to the ELP diet.Furthermore,the expressions of barrier-function related gene(MUC-1,MUC-2 and Occludin)were reduced as dietary CP level were reduced from LP to ELP-AA(P<0.05),whereas no significant difference were observed for MUC-1 and Occludin between pigs fed MP or LP diet and pigs fed ELP-CAS diet.The correlation analysis revealed positive linkage between Lactobacillus,butyrate,amines and gene expressions of MUC-1,MUC-2 and Occludin in the ileum.[Conclusions]ELP diet supplemented with AA would result in reduced microbial growth,metabolic activity and impaired barrier function in the ileum,however,casein supplementation could partly recover microbial communities and attenuate the adverse effects on barrier function.These results suggested that casein

关 键 词：蛋白水平 氮营养素 肠道微生物 屏障功能 

分 类 号：S828[农业科学—畜牧学]