Effects of TB and TB treatment on the pediatric intestinal microbiome

项目总结/摘要 虽然世界上近四分之一的人口潜伏感染结核分枝杆菌，但只有 一小部分发展为活动性结核病。2017年，有1000万人患上结核病，其中包括100万儿童。风险 雾化暴露后进展为活动性结核病的因素在很大程度上与年龄和免疫相关， 能力然而，需要改进方法来确定发展活动性结核病风险最高的人。 越来越多的人认识到，微生物组--由生活在地球上的数万亿种生物组成-- 在调节宿主代谢和免疫中起着重要作用。免疫途径 包括水生生物战胜入侵病原体的能力和某些植物群 刺激先天性免疫应答，随后影响适应性应答， 免疫力虽然大多数微生物组存在于人体肠道中，但其他重要的植物群也存在于人体肠道中。 在各种其他隔间，其中最相关的包括肺;有一个新兴的赞赏 这两个腔室之间的串扰称为肠-肺轴。关于结核病， 关于微生物组可能影响进展为活动性结核或疾病结果的风险的方式。虽然 众所周知，抗微生物剂的使用导致肠道植物群的破坏， 利福平、异烟肼、吡嗪酰胺和乙胺丁醇对微生物组的结核病治疗研究不足。的 推荐的结核病治疗疗程是连续的-至少六个月;因此， 持续的抗菌剂暴露时间可能对微生物组产生长期影响。 在本申请中，我们建议评估来自儿科参与者的肠道微生物群， 在坦桑尼亚农村接受结核病评估的儿童队列研究中招募;我们将使用 在六个月内的三个时间点收集粪便样本，包括任何TB治疗前的时间点 入会仪式我们假设，在结核病治疗开始之前，结核病“病例”将表现出对 与没有结核病的“对照”儿童相区别的肠道微生物组。此外，serial 对肠道微生物组的评估将证明结核病治疗如何与肠道微生物组的改变相关。 与不需要或不接受治疗的“对照”儿童相比， 肺结核治疗。我们将通过以下目标来测试我们的假设：1）评估肠道微生物组， 患有结核病的儿童与被排除患有结核病的儿童进行比较，2）确定 结核病治疗对肠道微生物组的组成、多样性和恢复力的纵向影响 与对照组相比，接受结核病治疗的儿童中。从粪便样品中提取DNA和宏基因组 测序将在我们在坦桑尼亚的长期合作研究基地进行，生物信息学 分析将由弗吉尼亚大学领导。这些目标的成功实现将突出表明， 肠道微生物组影响TB发病机制。

PROJECT SUMMARY/ABSTRACT While nearly one quarter of the world’s population is latently infected with Mycobacterium tuberculosis, only a small fraction develops active TB. In 2017, 10 million people developed TB, including 1 million children. Risk factors for progression to active TB after aerosolized exposure are, in large part, related to age and immunologic competency. However, improved methods are needed to identify people at highest risk of developing active TB. There is a growing appreciation that the microbiome—comprised of the trillions of organisms that live within the human—plays essential roles in the regulation of host metabolism and immunity. Immune pathways include the ability of commensal organisms to outcompete invasive pathogens and the ability of certain flora to stimulate innate immune responses, subsequently influencing adaptive responses that promote mucosal immunity. While the majority of the microbiome is found in the human intestines, additional important flora reside within various other compartments, most relevant of which includes the lungs; there is an emerging appreciation for the cross-talk between these two compartments, termed the gut-lung axis. Regarding TB, little is understood about ways in which the microbiome may impact risk of progression to active TB or disease outcomes. Although it is well known that the use of antimicrobials leads to a disruption in the intestinal flora, the impacts of first-line TB treatment with rifampin, isoniazid, pyrazinamide and ethambutol on the microbiome are understudied. The recommended course of TB treatment is lengthy—at least six months; therefore, there is a concern that this period of continuous antimicrobial exposure can have long-term effects on the microbiome. In this application, we propose to evaluate the intestinal microbiota from pediatric participants who were recruited in a cohort study of children from rural Tanzania undergoing evaluation for TB disease; we will use stool samples collected at three time points over six months, including a timepoint prior to any TB treatment initiation. We hypothesize that prior to TB treatment initiation, “cases” with TB will demonstrate perturbations in the intestinal microbiome that are distinguishable from “control” children without TB. Additionally, serial assessments of the intestinal microbiome will demonstrate how TB treatment is associated with alterations in microbiologic membership and functional potential compared to “control” children who did not need or receive TB treatment. We will test our hypotheses via the following aims: 1) evaluate the intestinal microbiome among children with TB disease compared children who have been ruled out from having TB disease, and 2) determine the longitudinal impacts of TB treatment on the composition, diversity, and resilience of the intestinal microbiome among children on TB treatment compared to controls. DNA extraction from stool samples and metagenomic sequencing will be conducted at our long-term collaborative research sites in Tanzania, and bioinformatic analyses will be led by the University of Virginia. Successful completion of these aims will highlight ways in which the intestinal microbiome affects TB pathogenesis.