Department of Animal Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Poult Sci. 2011 Oct;90(10):2301-10. doi: 10.3382/ps.2011-01488.
Early intestinal development is essential for chicken embryos to fulfill their maximal growth potential. Mannan oligosaccharide (MOS) is known to improve gut morphology, function, and innate immunity; therefore, we hypothesized that its administration in the prehatch period to the sterile intestine of embryos would affect intestinal development and functionality without mediation of gut microflora. The MOS was administered by in ovo feeding procedure to embryos 3 d before hatch. the effects of MOS administration on intestinal morphology, activity of the brush-border enzymes amino peptidase (AP) and sucrase isomaltase (SI) and mRNA abundance of AP, SI, sodium-dependent glucose cotransporter 1 (SGLT1), peptide transporter 1 (PepT1), secreted mucin (MUC2), and toll-like receptors (TLR2 and TLR4) were examined and compared with saline-injected and noninjected controls. Results show that on embryonic d 20 the only parameter affected was MUC2 mRNA abundance, which exhibited a 3-fold increase in the MOS group versus controls. On day of hatch more parameters were affected: a 20 to 32% increase in villus area was found in the MOS group compared with controls; crypt depth and number of goblet cells per villus were higher by 20 and 50%, respectively, compared with the saline group; and AP and SI activities were higher by 44 and 36%, respectively, compared with the noninjected control. In addition, an increase in fold change mRNA abundance of AP, SI, and TLR4 was observed in the MOS group compared with controls. However, on d 3 posthatch, a decrease in MOS effects was noted, indicating a temporally limited effect after administration of 1 dose. In ovo administration of MOS prehatch resulted in a hatching chick with more mature enterocytes and enhanced epithelial barrier and digestive and absorptive capacity at day of hatch. Results imply that the mechanism underlying the observed changes is not mediated through gut microflora but rather involves a direct effect of MOS on intestinal cells.
早期肠道发育对于鸡胚胎充分发挥其最大生长潜力至关重要。甘露寡糖（MOS）已被证实可以改善肠道形态、功能和固有免疫；因此，我们假设在孵化前将 MOS 注入无菌胚胎的肠道中，即使没有肠道微生物的介导，也会影响肠道发育和功能。MOS 通过胚内喂养程序在孵化前 3 天给予胚胎。研究了 MOS 给药对肠道形态、刷状缘酶氨基肽酶（AP）和蔗糖异麦芽糖酶（SI）的活性以及 AP、SI、钠依赖性葡萄糖共转运蛋白 1（SGLT1）、肽转运蛋白 1（PepT1）、分泌型粘蛋白（MUC2）和 Toll 样受体（TLR2 和 TLR4）mRNA 丰度的影响，并与盐水注射和未注射对照组进行了比较。结果表明，在胚胎第 20 天，唯一受影响的参数是 MUC2 mRNA 丰度，MOS 组与对照组相比增加了 3 倍。在孵化当天，更多的参数受到影响：MOS 组的绒毛面积增加了 20%至 32%，与对照组相比；隐窝深度和每绒毛的杯状细胞数量分别增加了 20%和 50%，与盐水组相比；AP 和 SI 活性分别增加了 44%和 36%，与未注射对照组相比。此外，与对照组相比，MOS 组的 AP、SI 和 TLR4 的 mRNA 丰度的倍数变化增加。然而，在孵化后第 3 天，MOS 作用的减少，表明在给予 1 剂量后，作用具有时间局限性。孵化前 MOS 的胚内给药导致孵化雏鸡的肠细胞更成熟，孵化日的上皮屏障和消化吸收能力增强。结果表明，观察到的变化的机制不是通过肠道微生物介导的，而是 MOS 对肠道细胞的直接作用。
