丁酸梭菌对脂多糖刺激的肉鸡免疫、抗氧化和肠道屏障功能的影响

Effects of Dietary Clostridium butyricum Supplementation on Immune,Antioxidant,and Intestinal Barrier Function in Broilers Challenged with Lipopolysaccharide

试验旨在研究饲粮添加丁酸梭菌对脂多糖(LPS)刺激的肉鸡免疫功能、抗氧化功能和肠道紧密连接蛋白表达的影响。试验选用256只1日龄雄性健康AA肉仔鸡,采用2×2双因子试验设计,两因子分别为饲粮处理[基础饲粮和基础饲粮中添加1 g/kg丁酸梭菌(活菌数为1×10^(8) CFU/g)]和应激处理(生理盐水和LPS)。试验分为4个处理,每个处理8个重复,每个重复8只鸡,试验期21 d。结果表明:LPS刺激显著提高肉鸡血浆免疫球蛋白A(IgA)、免疫球蛋白M(IgM)水平(P<0.05),显著降低空肠黏膜总抗氧化能力(T-AOC)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)的活性(P<0.05)。饲粮中添加丁酸梭菌显著提高肉鸡空肠黏膜T-AOC、CAT、GSH-Px、SOD的活性(P<0.05)。LPS刺激和丁酸梭菌添加对肉鸡空肠黏膜丙二醛(MDA)的含量具有交互作用,饲喂丁酸梭菌显著降低LPS刺激引起的肉鸡空肠黏膜MDA含量的升高(P<0.05)。LPS刺激显著提高肉鸡肠道干扰素-γ(IFN-γ)与白细胞介素-22(IL-22)的mRNA表达量(P<0.05),饲粮中添加丁酸梭菌显著提高肉鸡肠道IL-22的mRNA表达量(P<0.05)。LPS刺激显著降低Claudin-1与ZO-2的mRNA相对表达量(P<0.05),显著提高Claudin-2的mRNA相对表达量(P<0.05),饲粮中添加丁酸梭菌显著升高了ZO-2的表达(P<0.05)。LPS刺激和丁酸梭菌添加对肉鸡空肠紧密连接蛋白Occludin和ZO-1的mRNA表达具有交互作用,饲喂丁酸梭菌显著上调LPS刺激引起的肉鸡空肠Occludin和ZO-1的mRNA表达量下降(P<0.05)。综上,饲粮中添加1 g/kg丁酸梭菌(活菌数为1×10^(8) CFU/g)能提高LPS刺激的肉仔鸡的肠道抗氧化功能,维护肠道屏障功能。

The purpose of this experiment was to investigate the effects of dietary supplementation of Clostridium butyricum on immune function,antioxidant capacity and mRNA expression of intestinal tight junction protein in broilers challenged with lipopolysaccharide(LPS).A total of 256 one-day-old male healthy AA broilers were selected for a 2×2 factorial experimental design with two dietary levels[basal diet and C.butyricum supplementation at 1 g/kg of feedviable bacteria number:1×10^(8) CFU/g]and two stress treatments(saline and LPS injection).The experiment was divided into four treatments,with 8 replicates per group and eight broilers per replicate.The experiment lasted for 21 days.The results showed that LPS stimulation significantly increased plasma Immunoglobulin A(IgA)and Immunoglobulin M(IgM)levels(P<0.05)and significantly reduced the total antioxidant capacity(T-AOC),and catalase(CAT),glutathione peroxidase(GSH-Px)and superoxide dismutase(SOD)activity in the jejunal mucosa of broilers(P<0.05),while dietary C.butyricum supplementation significantly increased the jejunal T-AOC and the activity of CAT,GSH-Px,and SOD(P<0.05).The significant interaction of LPS stimulation and C.butyricum supplementation was observed on the content of malondialdehyde(MDA)in jejunum.C.butyricum supplementation significantly reduced the increase in MDA content of broiler jejunum caused by LPS stimulation(P<0.05).LPS stimulation significantly increased the mRNA expression of intestinal interferon-γ(IFN-γ)and interleukin-22(IL-22)in broilers(P<0.05),and dietary C.butyricum supplementation significantly increased the mRNA expression of IL-22(P<0.05).LPS stimulation significantly reduced the relative mRNA expression of Claudin-1 and ZO-2(P<0.05)in the jejunum,and significantly increased the Claudin-2 mRNA expression(P<0.05),while C.butyricum supplementation significantly increased the ZO-2 mRNA expression(P<0.05).The interaction between LPS stimulation and C.butyricum supplementation was observed on the Occludin and ZO-1 mRNA expression.C.butyricum supplementation significantly upregulated the reduced Occludin and ZO-1 mRNA expression caused by LPS stimulation(P<0.05).In conclusion,dietary addition of 1 g/kg of C.butyricum(viable bacteria number:1×10^(8) CFU/g)improved the intestinal antioxidant function and maintained the intestinal barrier function in broilers challenged with LPS.