Multiphase Chemo-Fluid Dynamics in the Stomach: Computational Models with Applications to Gastric Digestion in Health and Disease

人类消化是一个复杂的过程，摄入的食物被分解成营养物质，这些营养物质可以被身体用来生长、维持细胞和提供燃料。胃在消化中起着关键作用，因为它接收和储存摄入的食物，通过机械和化学处理将其混合、软化和分解，然后以调节的方式进行消化以进行吸收。本项目的目标是开发一套先进的计算工具来模拟胃的消化过程，并利用这些工具来全面研究胃消化背后的耦合化学-流体动力学机制。胃消化与我们这个时代一些最重要的健康问题有关：营养、食源性疾病、肥胖和糖尿病。这些疾病加在一起影响着世界各地数以亿计的人，这里进行的研究将直接应用于这些健康状况。这里开发的计算工具也将在机械、化学和生物医学工程的其他领域使用。学生培训将有助于培养一支拥有良好装备的科学家和工程师队伍，以应对日益增长的跨学科性质的研究和工程。与K-12社区的接触将利用当地与巴尔的摩高中的联系，包括妇女和少数族裔服务机构。该项目将开发计算工具，将多流体流动与动态变形区域中的生化反应相结合，并通过化学流体机制首次建立固体食物颗粒溶解的模型。使用这些工具，将产生对推动健康和疾病中胃消化的流动物理学的新的和重要的见解。胃消化的物理学是由三个同样重要的因素驱动的--胃运动、多流体/多相流体动力学和胃化学，该研究项目解决了这三个因素。特别是，这项研究将回答以下关键问题：胃运动如何决定胃内多流体食物混合物的混合、运输、化学加工和排空？酶活性对pH的敏感性如何与混合诱导的pH“小气候”相结合来调节富含碳水化合物、脂肪和蛋白质的食物在胃中的化学分解？固体食品是如何在复杂的胃化学流体动力学环境中加工的？颗粒-流体和颗粒-壁相互作用在这一过程中扮演了什么角色？该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Human digestion is a complex process wherein ingested food is broken into nutrients that can be used by the body for growth, cell maintenance, and fuel. The stomach plays a pivotal role in digestion since it receives and stores ingested food, mixes, softens and breaks it down via mechanical and chemical processing, and then undergoes digestion in a regulated manner for absorption. The goal of the current project is to develop a suite of advanced computational tools to model the digestion process in the stomach and to employ these tools to conduct a comprehensive investigation of the coupled chemo-fluid dynamic mechanisms that underlie gastric digestion. Gastric digestion is implicated in some of the most important health issues of our time: nutrition, food borne illnesses, obesity and diabetes mellitus. Together, these illnesses affect hundreds of millions of people around the world and the research conducted here will have direct application to these health conditions. The computational tools developed here will also find use in other arenas of mechanical, chemical and biomedical engineering. Student training will contribute to a cadre of scientists and engineers who are well-equipped to tackle the increasingly cross-disciplinary nature of research and engineering. Outreach to the K-12 community will leverage local connections with the Baltimore high schools, including women and minority serving institutions.The project will develop computational tools that couple multifluid flows with biochemical reactions in dynamically deforming domains as well as first-of-their-kind models for dissolution of solid food particles via chemo-fluid mechanisms. Using these tools, new and important insights into the flow physics that drives gastric digestion in health and disease, will be generated. The physics of gastric digestion is driven by three equally important factors – stomach motility, multifluid/multiphase fluid dynamics, and gastric chemistry and the research project tackles all three of these factors. In particular, the research will answer the following key questions: how does stomach motility determine the mixing, transport, chemical processing and emptying of multi-fluid food mixtures in the stomach? How does the pH-sensitivity of enzymatic activity combine with mixing-induced pH ``microclimates`` to modulate the chemical breakdown of carbohydrate, lipid and protein rich foods in the stomach? How are solid foods processed in the complex chemo-fluid dynamic environment of the stomach and what role do particle-fluid and particle-wall interactions play in this process?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.