益生菌发酵产物对肉鸡肠道形态和肠道屏障功能的影响

Effects of fermentation metabolite produced by probiotics on intestinal morphology and intestinal barrier function in chicken

为了研究益生菌发酵产物对肉鸡肠道形态和肠道屏障功能的影响,将495羽1日龄实验鸡随机分5组,每组9个重复,每重复11羽。各组饲喂不同饲粮:第Ⅰ组为正对照,基础日粮+杆菌肽锌80 mg·kg^(-1)饲料+硫酸粘菌素20 mg·kg^(-1)饲料+2%未发酵饲料;第Ⅱ组为负对照组,基础日粮+2%未发酵饲料;第Ⅲ组,基础日粮+1%未发酵饲料+1%发酵饲料;第Ⅳ组,基础饲粮+2%发酵饲料;第Ⅴ组,基础饲粮+2%灭菌发酵饲料。试验期70 d。试验结束时,取血清测内毒素(lipopolysaccharide,LPS)浓度,取回肠用于扫描电镜(SEM)检测,用无菌玻片刮取小肠黏膜用于测定肠道紧密连接蛋白的表达量。结果显示,第Ⅰ组、第Ⅳ组、第Ⅴ组血清内毒素水平有显著下降趋势;第Ⅴ组、第Ⅲ组绒毛比第Ⅱ组更长、更光滑,且其微绒毛长度显著高于第Ⅰ组、第Ⅳ组,但肠绒毛密度不及第Ⅰ组、第Ⅳ组。第Ⅴ组和第Ⅳ组肠道紧密连接蛋白表达量均显著上调。结果表明,不仅是益生菌,其发酵代谢产物对肠道健康也发挥重要作用。

In order to evaluate the effects of fermentation metabolite produced by probiotics on intestinal morphology and intestinal barrier function in chicken,495 1-d-old broilers were randomly allotted into 5 dietary treatments,namely： Treatment Ⅰ,positive control,basal diet ＋ bacitracin zinc 80 mg·kg^-1 feed ＋ colistin sulfate 20 mg·kg^-1 feed ＋ 2% unfermented feed; Treatment Ⅱ,negative control,basal diet ＋ 2% unfermented feed; TreatmentⅢ,basal diet ＋ 1. 0% fermented feed ＋ 1% unfermented feed; Treatment Ⅳ,basal diet ＋ 2. 0% fermented feed; Treatment Ⅴ,basal diet ＋ 2. 0% sterilized fermented feed. The serum was collected for lipopolysaccharide（ LPS） test,ileum was removed for observation of intestinal morphology by scanning electron microscopy（ SEM）,and the intestinal mucosa was scraped from the ileum by glass slide to determine the expression of intestinal tight junction. It was shown that the levels of serum lipopolysaccharide in treatment Ⅰ,Ⅳ,Ⅴ tended to be decreased significantly. The treatment Ⅴ and Ⅲ had higher and smoother intestinal villus in ileum than treatment Ⅱ,and thelength of microvilli in these 2 treatments were significantly higher than that in treatment Ⅰ and Ⅳ,but villi density was less than that of treatment Ⅰ and Ⅳ. The expression of intestinal tight junction protein in treatment Ⅴ and Ⅳwere up-regulated significantly. These results suggested that not only probiotics but also fermentation metabolite played role in intestinal barrier function.