Ecoculturing the Infant Gut Microbiome

构成人体微生物组的微生物数量超过了人体自身细胞的数量。这些微生物生活在我们的皮肤上，也生活在我们的体内，包括我们的唾液、乳腺和胃肠道中。占据胃肠道的微生物群落——肠道微生物群——是最大的。数据显示，不同人群的肠道微生物群落各不相同，生命的头几年是肠道发育的关键时期，对婴儿的直接健康和生物发育以及长期患病风险都有影响。因此，了解在这一关键时期影响肠道微生物群落发育的因素对于制定旨在改善美国和全球儿童发育和人口健康的政策和计划至关重要。这项纵向研究探讨了一个重要的，但尚未得到充分研究的因素-病原体暴露-在塑造婴儿肠道微生物群落中所起的作用，并考虑了由家庭社会和经济条件塑造的文化驱动的常规如何影响病原体暴露。该项目将对人类学、微生物学、公共卫生和医学领域的本科生和研究生进行交叉培训，使其成为一个跨学科的国际团队。在全球范围内，肠道病原体是婴儿发病和死亡的主要原因。即使在美国等高度发达的环境中，个人也会在环境、水和食物中以及通过与家畜的接触接触到肠道病原体。尽管它们在环境中无处不在，但关于它们在塑造婴儿肠道微生物群落演替中的作用的研究仍然很少。此外，虽然文化规范、当地生态和社会经济条件相互作用（即发育生态位）塑造了婴儿及其肠道微生物群落发育的环境，但生物培养模型尚未被用于理解演替过程和相关的婴儿健康结果。本研究通过利用生态文化理论作为框架来指导生活在高和低肠道病原体暴露条件下的巴西婴儿（出生-2岁）肠道微生物继承的纵向调查，解决了这两个空白。在三年的时间里，研究人员将(1)调查婴儿护理常规，照顾者赋予他们的意义以及构成它们的社会文化因素，(2)记录婴儿接触和感染肠道病原体，(3)确定感染常见肠道病原体改变或延迟典型肠道微生物成熟的程度，并影响社区稳定，(4)将肠道微生物演代的差异与儿童健康和发育结果联系起来。巴西贝伦是进行这项研究的理想地点。严重的经济不平等为研究一组生活在同一文化环境中，但获得公共卫生基础设施的机会和接触肠道病原体的风险存在巨大差异的婴儿提供了背景。此外，研究团队在富有成效的研究合作和开展工作的专业知识方面有着成功的记录。该研究将有助于阐明肠道病原体在婴儿肠道微生物群落演替中的作用，并将进一步应用生物培养模型来理解人类生物变异和健康。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The microorganisms comprising the human microbiome outnumber the human's own body cells. These microorganisms live on our skin, as well as inside our bodies, including in our saliva, mammary glands, and gastrointestinal tract. The microorganism community occupying the gastrointestinal tract - the gut microbiota - is the largest. Data show that the microbial community of the gut varies across human populations and that the first years of life are a critical period for its development, with implications for the infant's immediate health and biological development, as well as long-term risk of disease. Thus, understanding the factors that influence the development of the gut microbial community during this critical period is essential to inform policies and programs aimed at improving child development and population health within the USA and globally. This longitudinal study explores the role an important, but understudied factor - pathogen exposure - plays in shaping the gut microbial community of infants and considers how culturally driven routines, shaped by family's social and economic conditions, influences pathogen exposure. This project will cross-train undergraduate and graduate students in anthropology, microbiology, public health and medicine to work as an interdisciplinary and international team. Globally, enteric pathogens are a leading cause of infant morbidity and mortality. Even in highly-developed settings such as the USA, individuals come in contact with enteric pathogens in their environment, water and food, and through contact with domestic animals. Despite their ubiquity in the environment, research on their role in shaping succession of the infant gut microbial community remains sparse. Furthermore, while cultural norms, local ecology and socioeconomic conditions interact (i.e., developmental niche) to shape the context in which the infant and its gut microbial community develop, biocultural models have yet to be used to understand the succession process and related infant health outcomes. This study addresses both gaps by utilizing ecocultural theory as a framework to guide a longitudinal investigation of gut microbial succession among Brazilian infants (birth-2 years) living in conditions of high and low enteric pathogen exposure. Over a three-year period, researchers will (1) investigate infant care routines, the meanings caregivers attach to them and the sociocultural factors that structure them, (2) document infant exposure to and infection with enteric pathogens, (3) determine the extent to which infection with common enteric pathogens alters or delays typical gut microbial maturation and affects community stability, and (4) relate differences in gut microbial succession to child health and developmental outcomes. Belem, Brazil is an ideal site for this research. Stark economic inequality provides the context to study a cohort of infants living in the same cultural setting, but with dramatically different access to public health infrastructure and risk of enteric pathogen exposure. Additionally, the research team has a successful track record of productive research collaboration and the expertise to conduct the work. This study will help clarify the role enteric pathogens play in succession of the infant gut microbial community and will further the application of biocultural models for understanding human biological variation and health.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.