Fleige S, Preissinger W, Meyer H H D, Pfaffl M W
Physiology Weihenstephan, Center of Life and Food Sciences, Technische Universität München, 85354 Freising, Germany.
J Anim Sci. 2009 May;87(5):1731-8. doi: 10.2527/jas.2007-0494. Epub 2008 Dec 19.
Prebiotics and probiotics could represent an effective alternative to the use of synthetic antibiotics in nutrition. The mechanisms by which prebiotics affect the immune system have not yet been investigated in detail. Most effects have been attributed to increases in the innate and acquired immune responses. This study was conducted to elucidate the long-term effects of orally administered lactulose on the immune response in the intestinal tract of probiotic-fed calves. Preruminant calves were randomized to 3 feeding groups: milk replacer containing 1) no lactulose, 2) 1% lactulose, or 3) 3% lactulose. All 3 milk replacers contained 10(9) cfu Enterococcus faecium/kg. Messenger RNA expression of different cell activation markers, pro- and antiinflammatory cytokines, and IgA Fc receptor was investigated in the ileum, mesenterial lymph node, spleen, and white blood cells. A significantly greater number of blood lymphocytes were detected in the 3% lactulose group (P = 0.02) than in the control group. The expression results in male calves indicated that the transcription of IgA Fc receptor in the ileal mucosa of the 1% lactulose treatment group increased significantly (P = 0.04) and also tended to increase in the 3% lactulose group (P = 0.07). Furthermore, decreases in IL-10 and interferon-gamma mRNA expression were observed in the ileum (P = 0.04). The CD4-presenting lymphocytes were decreased significantly in the ileum (P = 0.04) and mesenteric lymph node (P = 0.01), whereas CD8-presenting lymphocytes were increased in the blood (P = 0.03) of females. Other proinflammatory cytokines (IL-1beta, IL-8, and tumor necrosis factor-alpha) and antiinflammatory cytokines (transforming growth factor-beta1) did not show significant differences in mRNA expression among treatment groups. The results indicate that additional lactulose feeding had an immunomodulatory effect on the composition of T-cell subsets in different immune compartments and had minor effects on pro- and antiinflammatory cytokine mRNA expression.
益生元和益生菌可能是营养领域中使用合成抗生素的一种有效替代方案。益生元影响免疫系统的机制尚未得到详细研究。大多数作用归因于先天免疫反应和获得性免疫反应的增强。本研究旨在阐明口服乳果糖对饲喂益生菌的犊牛肠道免疫反应的长期影响。反刍前犊牛被随机分为3个饲喂组：代乳粉分别含有1）不含乳果糖、2）1%乳果糖或3）3%乳果糖。所有3种代乳粉均含有10(9) cfu/kg屎肠球菌。在回肠、肠系膜淋巴结、脾脏和白细胞中研究了不同细胞活化标志物、促炎和抗炎细胞因子以及IgA Fc受体的信使核糖核酸表达。与对照组相比，3%乳果糖组检测到的血液淋巴细胞数量显著更多（P = 0.02）。雄性犊牛的表达结果表明，1%乳果糖处理组回肠黏膜中IgA Fc受体的转录显著增加（P = 0.04），3%乳果糖组也有增加趋势（P = 0.07）。此外，回肠中IL-10和干扰素-γ信使核糖核酸表达下降（P = 0.04）。雌性犊牛回肠（P = 0.04）和肠系膜淋巴结（P = 0.01）中呈递CD4的淋巴细胞显著减少，而血液中呈递CD8的淋巴细胞增加（P = 0.03）。其他促炎细胞因子（IL-1β、IL-8和肿瘤坏死因子-α）和抗炎细胞因子（转化生长因子-β1）在各处理组间的信使核糖核酸表达未显示出显著差异。结果表明，额外添加乳果糖对不同免疫区室中T细胞亚群的组成具有免疫调节作用，对促炎和抗炎细胞因子信使核糖核酸表达的影响较小。
