肠道作为动物机体最重要的组织器官，一方面负责膳食营养物质的消化吸收；另一方面发挥重要的屏障功能。氨基酸对肠道屏障功能、肠道发育以及细胞增殖具有重要的作用，然而色氨酸对肠道屏障及其紧密连接蛋白的作用以及机制还未揭示。本实验选取健康的生长肥育猪，根据体重随机分为2个组：对照组和0.2% Trp添加组。对其生长性能、器官指数、血液生化指标、肠道粘膜形态、肠道通透性及紧密连接蛋白基因进行了分析。实验表明，色氨酸增加了生长肥育猪的平均日采食量和血清中二胺氧化酶的活性，并降低了空肠紧密连接蛋白occludin和回肠claudin-1 mRNA的表达。因此，膳食色氨酸在一定程度上增加生长肥育猪肠道通透性。

The intestine is the most important organ in animals. It is not only responsible for the digestion and absorption of nutrients in foods, but also plays an important barrier function. Amino acids play an important role in the intestinal barrier function, intestinal development, and cell proliferation, but the mechanism of tryptophan (Trp) on intestinal barrier and tight junction proteins has not been revealed. In this experiment, healthy growing-finishing pigs were randomly divided into two groups according to body weight: a control group and a 0.2% Trp group. Growth performance, organ index, blood biochemical parameters, intestinal mucosa morphology, intestinal permeability, and the mRNA expression of intestinal tight junction proteins were analyzed. The results showed that tryptophan increased the average daily feed intake and serum diamine oxidase activity, while it reduced the mRNA expression of tight junction proteins, occludin (in the jejunum) and claudin-1 (in the ileum). Thus, to some extent, dietary tryptophan increases the intestinal permeability in growing-finishing pigs.

国家自然基金项目（31360552）