Finding innovations to improve calf gastrointestinal health

加拿大乳品业是该国最大的农业部门之一，每年为国内生产总值贡献近200亿美元。尽管增长迅速，奶牛的发病率和死亡率仍然很高，消化系统疾病占报告疾病的一半以上，占死亡的三分之一。当前管理实践中包含的几个因素对动物的肠道健康构成了挑战，损害了它们的肠道屏障功能，通常被称为“漏肠”。研究肠漏的影响因素是困难的，因为导致肠屏障完整性降低的条件也会影响其他组织的代谢。益生菌通过限制病原体入侵，为肠道微生物群提供稳定、营养丰富的环境，从而提高宿主的消化效率和免疫功能，促进肠道黏膜健康。补充helveticus乳杆菌（LH）已被证明可以通过调节肠道免疫功能来改善肠道屏障功能。然而，没有研究评估过LH对断奶前和断奶后反刍动物屏障功能、炎症和肠道健康的影响。此外，目前关于孤立研究漏肠模型的信息有限。以前的研究没有成功地尝试创建模型来诱导肠道渗漏，并且只关注全身炎症反应，而没有直接评估肠道通透性。因此，本提案旨在提高我们对这种消化系统疾病如何影响宿主生理和动物生产性能的理解。这项研究包括建立一个模型，以更好地了解肠漏的病因，所产生的模型将用于评估补充LH对屏障功能、炎症反应和能量代谢的影响。

The Canadian dairy industry is one of the largest agricultural sectors in the country, contributing almost 20billion dollars to the GDP every year. Despite this rapid growth, dairy calves continue to suffer from high ratesof morbidity and mortality, with digestive disorders accounting for over half of reported illnesses and one-thirdof deaths. Several factors embedded within current management practices pose challenges to animal guthealth, compromising their tract barrier function, normally referred to as "leaky gut". Studying the contributingfactors of leaky gut is difficult because the conditions responsible for reducing intestinal barrier integrity canalso affect the metabolism of other tissues. Probiotics promote gut mucosal health by limiting pathogeninvasion and providing a stable, nutrient-rich environment for gut microbiota, thereby enhancing host digestiveefficiency and immune function. Lactobacillus helveticus (LH) supplementation has been shown toimprove gut barrier function through modulation of gut immune function. However, no studies have evaluatedthe effects of LH on barrier function, inflammation, and gut health in ruminants during preweaning andpostweaning. Furthermore, there is currently limited information regarding models to study leaky gut inisolation. Previous research has unsuccessfully attempted to create models to induce leaky gut and has focusedsolely on the systemic inflammatory response without directly assessing gut permeability. Therefore, thisproposal aims to improve our understanding of how this digestive disorder impacts host physiology and animalperformance. This research encompasses the development of a model to better understand the aetiology ofleaky gut and the models generated will serve to evaluate the impact of LH supplementation onbarrier function, inflammatory response and energy metabolism.