Effect of Lactobacillus rhamnosus GG on microbial flora and immune responses of weaned piglets challenged with K88+enterotoxigenic Escherichia coli
Eighteen just weaned barrows at 19 d of age were used to investigate the effectsof feeding Lactobacillus rhamnosus GG(LGG)on the intestinal and fecal microbiotas，intestinamucosal immunity and systemic inflammatory responses of Escherichia coil(E.coli)K88+-challenged pigs.During the experiment，rectal temperatures of all pigs，number of diarrheicpigs and duration of diarrhea were recorded，and feces of all pigs were collected every other dayfor microbial culture.Pigs were allotted to three treatments including：1) nonchallenged Control(NCON)；2) challenged Control(coon)；3) LGG solution(LGG).On d 8 after weaning，pigs in the coon and LGG groups were orally challenged with E. Coli K88+ solution.whereas pigs in theNCON group were orally inoculated with sterilized physiological saline.Blood samples werecollected at 0(baseline)，6，12，24，48 and 150 h after the challenge for serum cytokine，acutephase protein and white blood cell(WBC)measurements.At 150h postchallenge，all pigs werekilled.samples of blood，iIltestinal Contents and mucosa were collected.Compared with coon，LGG reduced diarrhea rate in group LGG LGG significantly influenced bacterial Counts of E.Coli，lactobaillus.bifidobacteria and bacteroids in feces，and E. Coli，lactobaillus，bifidobacteria，enterococcus and bacteroids in the intestinal Contents.In jejunum and ileum respectively，level ofsIgA is higher in group LGG than in group coon.Serum IL-6 were greater in group coon at 6，12 and 48 h than in group NCON，and were greater in group coon at 6 and 12 h than in groupLGG,respectively.Higher Concentrations of serum TNF-α were observed in group LGGcompared with groups NCON and coon at 6 h，respectively.Serum IL-1β were greater in groupNCON than in group LGG at 6 hour and group coon at 24 hour，respectively.These resultsindicate that feeding LGG was beneficial in preventing postweaned diarrhea induced by K88+ E.Coli，possibly via modulating intestinal microflora and intestinal mucosal sIgA.LGG also hasmodulatory effects on the production of inflammatory cytokines during E.Coli infection.
乳酸杆菌 微生物植物群 断奶仔猪 免疫反应 大肠埃希氏菌
L. Zhang Y. Q. Xu H. Y. Liu T. Lai J. L.Ma Y. H. Zhu J. F. Wang
College of Veterinary Medicine,China Agricultural University,Beijing 100193,P. R. China
国内会议
广州
英文
814-828
2008-11-01（万方平台首次上网日期，不代表论文的发表时间）