饲粮不同能量来源对断奶仔猪肠道功能和粘膜更新的影响及机制研究

The rapid proliferation of intestinal epithelial provides a basis for intestinal damage repair (e.g. weaning stress), and requires energy by oxidative metabolism of nutrients. Amino acids, glucose and fatty acids as the main energy supply substances of enterocytes, their metabolism on intestinal epithelial cell has important implications for the nutritional regulation of weaning piglets. Our group has studied on intestinal epithelial renewal process by proteomics and the results show that weaning changed the energy metabolism on villus and crypt cells of piglets, but the effect of different energy sources on intestinal epithelial cell renewal is still unclear in weaning piglets. Therefore, this project intends to investigate the different energy sources (glutamine, glucose and fatty acids) on the morphology and function of intestine and epithelial cell renewal on weaning piglets. And the results will disclosure the mechanisms of different energy sources on mucosal turnover of weaning piglets through proteomics and metabonomics. Our results will be helpful to provide the intestinal nutrient metabolism and nutritional needs on weaning piglets, and theoretical basis for weaning stress.

肠道粘膜上皮的快速增殖为仔猪断奶应激等肠道损伤修复提供了基础，同时也需要大量养分氧化代谢提供能量。氨基酸、葡萄糖和脂肪酸作为肠道上皮的主要供能物质，它们在断奶仔猪肠道的利用和代谢研究对仔猪断奶期的营养调控具有重要意义。本研究组前期对仔猪肠道上皮更新过程的蛋白质组学结果表明仔猪断奶后影响了绒毛细胞和隐窝细胞能量代谢，但不同的能量来源对断奶仔猪肠上皮细胞更新的影响还不清楚。因此本项目拟对断奶仔猪添加不同能量来源（谷氨酰胺、葡萄糖和脂肪酸），研究其对断奶仔猪肠道形态和功能、肠上皮细胞更新的影响，并结合蛋白质组学和代谢组技术，探讨了不同能量来源对断奶仔猪肠道上皮更新影响的分子机制。为阐明断奶仔猪肠道养分代谢及营养需要，调控仔猪断奶期肠道营养、缓解断奶应激提供理论依据。

项目比较了饲粮中添加等能的葡萄糖、谷氨酰胺和豆油饲喂28天对断奶仔猪生长和肠道功能的影响，结果表明添加葡萄糖或豆油组的仔猪生产性能优于谷氨酰胺组，这可能源于葡萄糖和豆油具有更好的适口性；三组仔猪肠道形态和肠道黏膜消化酶的表达没有显著区别。断奶14天后三组之间肠道转运载体和紧密连接蛋白的表达没有差异，断奶28天后三组肠道转运载体的表达呈现显著差异，葡萄糖添加组相比于谷氨酰胺和豆油组具有更好的肠道紧密连接基因表达。谷氨酰胺可能改善了仔猪机体免疫和肠道抗氧化能力。葡萄糖、谷氨酰胺和豆油对仔猪肠道隐窝细胞蛋白质代谢有不同的影响，相比于豆油，葡萄糖或谷氨酰胺可能是空肠隐窝细胞更好的能量供应物质。