摘要
本研究以大白猪为对照,旨在分析不同水平麸皮替代基础日粮对梅山猪血液常规和血液生化、血清免疫球蛋白及大肠黏膜分泌型免疫球蛋白A(SIgA)等免疫指标的影响,并进一步从宿主肠道基因和微生物角度初步探究日粮纤维影响梅山猪免疫指标的机理。试验选取梅山猪(初始体重(67.08±1.53)kg)、与梅山猪相同生理阶段的大白猪(初始体重(81.04±1.64)kg)各28头,随机各分成4个处理组,每组7个重复,每个重复1头猪。预试期7 d,试验猪只自由采食基础日粮;正试期28 d,分别饲喂基础日粮(Basal),以及7%、10.5%和14%麸皮替代基础日粮(7%WBR、10.5%WBR和14%WBR)的试验日粮。正试期所有猪自由采食和饮水,试验结束屠宰全部试验猪,采集血液样品进行血常规、血生化和血清免疫球蛋白指标测定;采集盲肠和结肠黏膜样品进行SIgA测定以及结肠黏膜转录组测序;采集结肠内容物进行宏基因组测序。结果表明:1)随日粮麸皮替代水平的升高,梅山猪的嗜酸性粒细胞数、嗜酸性粒细胞百分比和嗜碱性粒细胞数呈线性降低(P<0.05)。14%WBR组梅山猪的血清球蛋白水平显著高于大白猪(P<0.05);2)随日粮麸皮替代水平的升高,梅山猪的血清免疫球蛋白M(IgM)和免疫球蛋白G(IgG)呈线性升高(P<0.01),大白猪的血清IgM呈线性升高(P<0.01),且14%WBR组梅山猪的血清IgG的浓度显著高于大白猪(P<0.01)。另外,与Basal组相比,14%WBR组梅山猪的结肠黏膜SIgA浓度极显著升高(P<0.01),而大白猪没有显著变化;3)为初步解析14%WBR组梅山猪的结肠黏膜SIgA浓度升高的机理,一方面选择Basal组和14%WBR组梅山猪的结肠黏膜进行转录组测序,共鉴别到38个差异表达基因,GO富集到的功能条目和KEGG富集到的信号通路主要与免疫系统相关,调控肠道SIgA产生的基因CD4分子(CD4)和CC趋化因子受体9(CCR9)的表达量在14%WBR组显著提高(P<0.05)。另一方面选择Basal组和14%WBR组梅山猪的结肠内容物进行宏基因组测序,LEFSe分析发现14%WBR组显著富集到2个科水平微生物、1个属水平微生物和5个种水平微生物。相关性分析揭示,种水平差异微生物与调控肠道SIgA产生的宿主黏膜基因CD4和CCR9不存在直接互作关系(P>0.05),但Sutterella sp.、Clostridium sp.CAG:138、Clostridium sp.CAG:762和Nitrospira sp.与血清IgG呈显著正相关,Clostridium sp.CAG:138和Nitrospira sp.与结肠黏膜SIgA呈显著正相关。对Basal组和14%WBR组梅山猪的结肠微生物进行KEGG功能注释,发现14%WBR组IgA产生的肠道免疫网络功能通路(intestinal immune network for IgA production)的相对丰度显著高于Basal组(P<0.05)。综上可知,用麸皮替代部分基础日粮可以降低梅山猪机体的炎症水平,增强梅山猪的体液免疫和促进结肠健康,并且14%麸皮替代基础日粮对梅山猪的有益作用优于大白猪。同时本文还发现日粮纤维对梅山猪结肠黏膜SIgA的影响可能是通过上调结肠黏膜CD4和CCR9基因的表达和影响肠道微生物的组成,从而增强IgA产生的肠道免疫网络功能通路,改善肠道屏障功能,促进机体健康。
This study aimed to analyze the effects of different levels of wheat bran replacing basal diet on blood routine,blood biochemistry,serum immunoglobulin,and large intestinal mucosal secretory immunoglobulin A(SIgA)of Meishan pigs,using Large White pigs as the control.Then further studied the mechanism of dietary fiber affecting the immune indicators of Meishan pigs from the perspective of host intestinal genes and microorganisms.In this study,28 Meishan pigs(initial body weight was(67.08±1.53)kg)and 28 Large White pigs(initial body weight was(81.04±1.64)kg,at the same physiological stage as Meishan pigs)were randomly and respectively divided into 4 treatment groups with 7 replications in each group for 1 per duplicate.During the pre-feeding period of 7 days,all pigs were fed the basal diet,and during the main trial period of 28 days,they were fed with the basal diet(Basal),7%,10.5%,and 14%wheat bran substituted in the basal diet(7%WBR,10.5%WBR and 14%WBR),respectively.During the trial period,all pigs had free access to food and water.At the end of the experiment,all pigs were slaughtered,and blood samples were collected for the determination of blood routine,blood biochemical and serum immunoglobulin indicators.Cecal and colonic mucosal samples were collected for SIgA determination,and colonic mucosal were collected to perform RNA-seq.Colonic contents were collected for metagenomic sequencing.The results showed that:1)With the increasing of wheat bran replacing basal diet level,the number of eosinophils and basophils,and percentage of eosinophils decreased in Meishan pigs linearly,(P<0.05),and the serum globulin level of Meishan pigs in the 14%WBR group were significantly higher than that of Large White pigs(P<0.05).2)With the increasing of wheat bran replacing basal diet level,the serum immunoglobulin M(IgM)and immunoglobulin G(IgG)of Meishan pigs increased linearly,(P<0.01),and the serum IgM of Large White pigs increased(linear,P<0.01).The serum IgG concentration of Meishan pigs in the 14%WBR group was significantly higher than that of Large White pigs(P<0.01).In addition,compared with the Basal group,the concentration of colonic mucosal SIgA of Meishan pigs in the 14%WBR group was significantly increased(P<0.01),but there was no significant change between the 14%WBR group and the Basal group in Large White pigs.3).To elucidate the mechanism of increased colonic mucosal SIgA concentration of Meishan pigs in the 14%WBR group,on the one hand,the colonic mucosa of Meishan pigs in the Basal group and the 14%WBR group were selected to perform RNA-seq.A total of 38 differentially expressed genes were identified,and the functional items enriched by GO and the signaling pathways enriched by KEGG were mainly related to the immune system.The expression of CD4 molecule(CD 4)and C-C chemokine receptor 9(CCR 9)regulating intestinal SIgA production was significantly increased in the 14%WBR group(P<0.05).On the other hand,the colonic contents of Meishan pigs in the Basal group and the 14%WBR group were selected to perform metagenomic sequencing.The results of LEFSe analysis showed that 14%WBR group was significantly enriched to 2 family-level microorganisms,1 genus-level microorganism,and 5 species-level microorganisms.Correlation analysis revealed that there was no direct interaction between species-level different the differentical microorganisms at speices level and the host mucosal genes which regulating the production of intestinal SIgA(P>0.05),but Sutterella sp.,Clostridium sp.CAG:138,Clostridium sp.CAG:762 and Nitrospira sp.were significantly positively correlated with serum IgG.Moreover,Clostridium sp.CAG:138 and Nitrospira sp.were significantly positively correlated with colonic mucosal SIgA.Finally,KEGG functional analysis found that the relative abundance of the intestinal immune network for IgA production in the 14%WBR group was significantly higher than that of the Basal group(P<0.05).In summary,replacing part of the basal diet with wheat bran could reduce the inflammatory level,enhance humoral immunity and promote the health of the colon of Meishan pigs,and the beneficial effect of 14%wheat bran replaced basal diet on Meishan pigs is better than that on Large White pigs.In addition,this study also found that the effects of dietary fiber on colonic mucosal SIgA of Meishan pigs may be through up-regulating the expression of CD 4 and CCR 9 genes in the colonic mucosa,and affecting the composition of intestinal microorganisms,thus enhancing the functional pathway of intestinal immune network produced by for IgA production,improving intestinal barrier function and promoting body health.
作者
李平会
蒲广
王中宇
周五朵
牛培培
吴承武
侯黎明
黄瑞华
李平华
LI Pinghui;PU Guang;WANG Zhongyu;ZHOU Wuduo;NIU Peipei;WU Chengwu;HOU Liming;HUANG Ruihua;LI Pinghua(Institute of Swine Science,Nanjing Agricultural University(Key Laboratory of Evaluation and Utilization of Livestock and Poultry(PIG)Resources,Ministry of Agriculture and Rural Affairs(Nanjing)),Nanjing 210095,China;Huaian Academy,Nanjing Agricultural University,Huai′an 223001,China;Industrial Technology System Integration Innovation Center of Jiangsu Modern Agriculture(PIG),Nanjing 210095,China)
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2023年第10期4260-4277,共18页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
国家重点研发项目(2021YFD1301101)
江苏省现代农业(生猪)产业技术体系建设项目[JATS(2022)452,JATS(2022)205]。
关键词
麸皮
猪
免疫
微生物
wheat bran
pig
immunity
microorganism
