High-throughput surveillance of gut mucosal polysaccharides

项目摘要 肠道微生物群是哺乳动物胃肠道中密集的多微生物群落， 参与人类发展、健康和疾病。微生物群的分类组成发生了变化 在许多不同肠道疾病（包括炎症性肠道疾病和 结肠直肠癌虽然与疾病相关的微生物群变化的潜在原因尚不清楚， 组织表现出粘膜多糖的产生改变，所述粘膜多糖作为微生物群的营养物。我们 假设粘膜多糖特性和丰度的变化促进了 通过有利于或不利于各种肠道分类群的扩展，这些分类群专门研究微生物群的组成。 利用各种粘膜多糖。然而，确定粘膜多糖的这种变化， 由于缺乏快速有效的方法来监测分馏产物， 从人粘膜样品中提取的多糖制剂。幸运的是，一些微生物群成员 已经进化出了专门的传感器蛋白， 结构和直接的快速和戏剧性的变化基因表达。这些传感器可以区分 组成相似但结构不同的多糖，即使当它们的同源物 配体以相对低的丰度存在于异源多糖混合物中。在这里，我们利用 这些多糖传感器的特异性，以开发阵列报告文库，采用肠道微生物， 评价异质混合物中粘膜多糖含量的变化。这项工作将发展一个高- 通过监测系统来确定肠粘膜的多糖含量，有效地监测 分离复杂的多糖混合物，并将细菌基因含量分配给利用 单独的多糖。最终，这个工具集将揭示肠道疾病如何促进肠道组织的变化。 微生物群组成和输出，确定推定的疾病生物标志物，并提供有价值的见解， 控制人类肠道微生物群的王国间相互作用。

Project Summary The gut microbiota is a dense polymicrobial consortium housed in the mammalian gastrointestinal tract that participates in human development, health and disease. The taxonomic composition of the microbiota changes during the progression of many different intestinal diseases including inflammatory bowel disease and colorectal cancers. While the causes underlying disease-associated microbiota changes are unclear, diseased tissues exhibit altered production of mucosal polysaccharides, which serve as nutrients for the microbiota. We hypothesize that changes in mucosal polysaccharide identity and abundance facilitate alterations in the microbiota composition by favoring or disfavoring the expansion of various gut taxa that specialize in the utilization of various mucosal polysaccharides. However, identifying such changes in mucosal polysaccharide content and abundance is limited by the absence of rapid and efficient methods to monitor fractionated polysaccharide preparations extracted from human mucosal samples. Fortuitously, some microbiota members residing in the gut have evolved specialized sensor proteins that detect specific complex polysaccharide structures and direct rapid and dramatic changes in gene expression. These sensors can distinguish between compositionally similar yet structurally distinct polysaccharides and are activated even when their cognate ligand is present in relatively low abundance in a heterogenous polysaccharide mixture. Here, we harness the specificity of these polysaccharide sensors to develop arrayed reporter libraries that employ gut microbes to evaluate changes in mucosal polysaccharide content in heterogenous mixtures. This work will develop a high- throughput surveillance system to define the polysaccharide content of the gut mucosa, efficiently monitor fractionation of complex polysaccharide mixtures and assign bacterial gene content to the utilization of individual polysaccharides. Ultimately, this toolset will unveil how intestinal diseases promote changes in the microbiota composition and output, identify putative disease biomarkers and offer valuable insight into the inter-kingdom interactions governing the human gut microbiota.