Engineering a Small Intestinal Microbiome to Evaluate Food Additive Exposure

项目总结 纳米材料越来越多地用于消费品、加工食品和食品包装，但很少有 研究已经确定了摄入纳米颗粒的后果。这项工作的最终目标是 确定摄入的金属氧化物纳米颗粒是否以及如何改变微生物种群和肠道功能。 已经开发了胃肠道模型和一组功能分析，初步数据表明 饮食剂量的原始金属氧化物纳米颗粒减少矿物质，葡萄糖和脂肪的吸收。这些 吸收的减少是由于纳米颗粒诱导的微绒毛结构的改变。出现了一个 模型中单一种类的有益细菌可防止纳米颗粒后营养吸收的变化 早期的结果表明，纳米颗粒与生物成分的反应与金属有关 氧化态。中心假设是，微生物群可以使摄入的金属氧化物纳米材料解毒， 但高剂量或长期接触会导致小肠生物失调，改变肠道上皮结构，并 导致屏障性能和养分吸收减少。这一假设将通过三个目标进行检验。 首先，单独的细菌菌株将被引入到胃肠道模型中，并从分子、功能和 急、慢性金属对结构上皮特征、微生物活性和遗传毒性的影响 将确定氧化物纳米颗粒的暴露情况。其次，将设计一个上消化道细菌的模拟群落 并纳入胃肠道模型以确定急性或慢性金属氧化物纳米颗粒的影响 在静态和流体条件下暴露于微生物群落动态和上皮细胞特性。 第三，肉鸡模型(Gallus Gallus)，这是一种成熟和可靠的量化营养的方法 生物利用度、刷状缘酶活性和微生物组改变将用于验证体外结果。 该系统将是第一个使用生理上真实的、可重现的、 利用人类来源的细胞的高通量方法，将提供对纳米颗粒-生物相互作用的洞察。 这些有价值的信息对健康和安全决策是必要的，并将提供给两位研究人员 和消费者。这项工作的科学成果有两个：1)建立的模型将允许 评估细菌对胃肠道健康和功能的贡献以及确定 我们的饮食支配着微生物的动态；2)收集的数据将决定金属氧化物的主要行为 具有生物GI组件的纳米颗粒，并允许在广泛的类别中进行外推 摄取的纳米材料。

PROJECT SUMMARY Nanomaterials are increasingly used in consumer products, processed food, and food packaging, and few studies have determined the consequences of nanoparticle ingestion. The ultimate goal of this work is to determine if and how ingested metal oxide nanoparticles alter microorganism populations and intestinal function. A model of the GI tract and a panel of functional assays have been developed, and preliminary data shows that dietary doses of pristine metal oxide nanoparticles decrease mineral, glucose, and lipid absorption. These decreases in absorption are due to nanoparticle-induced alterations in microvilli structure. The presence of a single species of beneficial bacteria in the model prevents changes in nutrient absorption following nanoparticle exposure, and early results suggest that nanoparticle reactivity with biological components is related to metal oxidation state. The central hypothesis is that the microbiota can detoxify ingested metal oxide nanomaterials, but high doses or chronic exposure can induce small intestinal dysbiosis, alter intestinal epithelial structure, and result in decreased barrier properties and nutrient absorption. This hypothesis will be tested with three aims. First, individual strains of bacteria will be introduced into the GI tract model and molecular, functional, and structural epithelial characteristics and microbial viability and genotoxicity affected by acute and chronic metal oxide nanoparticle exposure will be identified. Second, a mock community of upper GI bacteria will be engineered and incorporated into the GI tract model to determine the effects of acute or chronic metal oxide nanoparticle exposure on microbial community dynamics and epithelial cell properties under both static and fluidic conditions. Third, a broiler chicken model (Gallus gallus), which is an established and robust method for quantifying nutrient bioavailability, brush border enzyme activity, and microbiome alterations will be used to validate in vitro results. This system, which will be the first to model upper GI conditions using a physiologically realistic, reproducible, high-throughput method with human-derived cells, will provide insight into nanoparticle-biological interactions. This valuable information is necessary for health and safety decisions and will be provided to both researchers and consumers. The scientific outcomes of this work are twofold: 1) the model created will allow quantitative assessment of the contributions of bacteria toward GI health and function and the ability to determine how what we eat governs microbial dynamics; and 2) data collected will determine the overarching behavior of metal oxide nanoparticles with biological GI components and allow for extrapolation across a broad class of commonly ingested nanomaterials.