Maternal and Infant Microbiome Determinants of Brain and Behavioral Development

描述(申请人提供)：婴儿的肠道微生物区系，通过母亲和早期养育环境获得，通过刺激免疫、内分泌和肠道神经系统的成熟，在建立功能性胃肠道和促进健康方面发挥关键作用。我们的项目使用非人类灵长类动物模型来具体确定婴儿肠道微生物群影响大脑发育的机制路径，以及在生命第一年期间的情绪和行为反应。在怀孕和哺乳期间，母亲的微生物组将受到实验控制，使我们能够产生具有两个不同微生物组特征的婴儿。微生物群落分析将在Illumina MiSeq上运行，以获取高质量的16S rRNA数据，以跟踪婴儿与母亲在一起时的微生物区系的发育，以及随后在断奶后肠道细菌群落因食用固体食物和接触同伴而重组的情况。在初步结果的基础上，我们重点研究了两组信号介质：1)肠道细菌产生的神经化学物质，包括单胺类神经递质和GABA；2)血液和鞘内的炎性细胞因子活性。在一岁时，最先进的神经成像将用于大脑皮质区域(灰质和白质体积)的结构分析，并使用扩散张量成像来量化髓鞘形成的速度。在R21的初始阶段，我们将验证 20只具有不同微生物群系的幼猴可以可靠地产生，而且种群差异持续存在，这使得我们能够创建由具有可比微生物群的婴儿组成的同龄人社会群体。在R33阶段，将产生更大的40名婴儿队列，使我们能够使用粪便移植方法来系统地改变肠道微生物区系的组成，并测试行为和神经轨迹将转移到 捐献动物的基因。该项目利用了大型灵长类动物繁育设施的独特资源，使我们能够在受控的环境条件下评估大量的幼猴，以及4个机构的合作研究团队的多学科专业知识和资源。采用了创新的方法，包括对肠道组织样本进行活检收集，以验证来自更常规收集的直肠拭子的定向代谢组板的测序和神经化学结论。我们的项目直接针对RFA的一个核心原则，即调查 母婴微生物群对行为和大脑成熟的影响，并确定调节失调的微生物群是否与非典型发育有关。采用了多层次、分子生物学和发育神经科学的方法。这项研究与儿童健康有明确的翻译相关性，有助于现有的发现表明 微生物组在几种儿科疾病中很明显。我们准备验证新的生物标志物，以跟踪肠道微生物区系对系统生理学的影响，并在肠道和肠道神经系统如何与微生物群相互作用以影响中枢神经系统的正常功能和发育方面取得新的发现。

DESCRIPTION (provided by applicant): The gut microbiota of the infant, acquired by exposure to the mother and the early rearing environment, plays a critical role in establishing a functional gastrointestinal tract and promoting health via stimulating the maturation of the immune, endocrine, and enteric nervous systems. Our project uses a nonhuman primate model to specifically determine the mechanistic pathways through which the infant's gut microbiome affects brain development, as well as emotional and behavioral responsiveness during the first year of life. The mother's microbiome will be experimentally controlled during the pregnancy and nursing periods, enabling us to generate infants with two distinctive microbiome profiles. Microbial community analyses will be run on Illumina MiSeq to acquire high quality 16S rRNA data in order to track the development of the infant's microbiota while it is with the mother, and subsequently after weaning when the gut bacterial community is reorganized, due to the consumption of solid foods and exposure to peers. Based on preliminary results, we focus on two sets of signaling mediators: 1) the production of neurochemicals by gut bacteria, including monoamine neurotransmitters and GABA, and 2) inflammatory cytokine activity in the blood and intrathecal compartments. At one year of age, state-of-the-art neuroimaging will be used for structural analyses of cortical brain regions (gray and white matter volumes), and for quantifying the pace of myelination with diffusion tensor imaging. During the initial R21 phase, we will verify that 20 infant monkeys with distinct microbiome profiles can be reliably generated, and that population differences persist, allowing us to create peer social groups comprised of infants with comparable microbiota. During the R33 phase, a larger cohort of 40 infants will be generated, enabling us to also use fecal transplant methods to systematically change the composition of the gut microbiota and to test the hypothesis that behavioral and neural trajectories will shift to that of the donor animal. This project takes advantage of the unique resources of a major primate breeding facility, permitting us to evaluate a large number of infant monkeys under controlled environmental conditions, and the multi-disciplinary expertise and resources of the collaborating research team at 4 institutions. Innovative methods are employed, including the biopsy collection of gut tissue specimens to validate sequencing and neurochemical conclusions from directed metabolomic panels derived from the more routinely collected rectal swabs. Our project directly addresses a central tenet of the RFA, which is to investigate the influence of the maternal and infant microbiome on behavioral and brain maturation, and to determine if a dysregulated microbiome is associated with atypical development. Multi-tiered, molecular biology and developmental neuroscience approaches are employed. This research has a clear translational relevance for child health, contributing to extant findings that indicate an abnormal microbiome is evident in several pediatric disorders. We are poised to validate new biomarkers for tracking the influence of the gut microbiota on systemic physiology and to make novel discoveries on how the gut and enteric nervous system interface with the microbiome to influence the normal functioning and development of the central nervous system.