Manus Melissa B, Kuthyar Sahana, Perroni-Marañón Ana Gabriela, Núñez-de la Mora Alejandra, Amato Katherine R
Department of Anthropology, Northwestern University, Evanston, Illinois, USA
Department of Anthropology, Northwestern University, Evanston, Illinois, USA.
mSystems. 2020 Nov 3;5(6):e00834-20. doi: 10.1128/mSystems.00834-20.
Daily practices put humans in close contact with the surrounding environment, and differences in these practices have an impact on human physiology, development, and health. There is mounting evidence that the microbiome represents an interface that mediates interactions between the human body and the environment. In particular, the skin microbiome serves as the primary interface with the external environment and aids in host immune function by contributing as the first line of defense against pathogens. Despite these important connections, we have only a basic understanding of how the skin microbiome is first established, or which environmental factors contribute to its development. To this end, this study compared the skin bacterial communities of infants ( = 47) living in four populations in Mexico and the United States that span the socioeconomic gradient, where we predicted that variation in physical and social environments would shape the infant skin microbiome. Results of 16S rRNA bacterial gene sequencing on 119 samples (armpit, hand, and forehead) showed that infant skin bacterial diversity and composition are shaped by population-level factors, including those related to socioeconomic status and household composition, and vary by skin site and infant age. Differences in infant-environment interactions, including with other people, appear to vary across the populations, likely influencing infant microbial exposures and, in turn, the composition of infant skin bacterial communities. These findings suggest that variation in microbial exposures stemming from the local environment in infancy can impact the establishment of the skin microbiome across body sites, with implications for developmental and health outcomes. This study contributes to the sparse literature on the infant skin microbiome in general, and the virtually nonexistent literature on the infant skin microbiome in a field setting. While microbiome research often addresses patterns at a national scale, this study addresses the influence of population-level factors, such as maternal socioeconomic status and contact with caregivers, on infant skin bacterial communities. This approach strengthens our understanding of how local variables influence the infant skin microbiome, and paves the way for additional studies to combine biological sample collection with questionnaires to adequately capture how specific behaviors dictate infant microbial exposures. Work in this realm has implications for infant care and health, as well as for investigating how the microbial communities of different body sites develop over time, with applications to specific health outcomes associated with the skin microbiome (e.g., immune system development or atopic dermatitis).
日常行为使人类与周围环境密切接触，这些行为的差异会对人类生理、发育和健康产生影响。越来越多的证据表明，微生物群是介导人体与环境之间相互作用的一个界面。特别是，皮肤微生物群作为与外部环境的主要界面，通过作为抵御病原体的第一道防线来辅助宿主免疫功能。尽管存在这些重要联系，但我们对皮肤微生物群最初是如何建立的，或者哪些环境因素有助于其发育，只有基本的了解。为此，本研究比较了生活在墨西哥和美国四个跨越社会经济梯度的人群中的47名婴儿的皮肤细菌群落，我们预测身体和社会环境的差异会塑造婴儿皮肤微生物群。对119个样本（腋窝、手部和前额）进行的16S rRNA细菌基因测序结果表明，婴儿皮肤细菌的多样性和组成受到人群水平因素的影响，包括与社会经济地位和家庭构成相关的因素，并且因皮肤部位和婴儿年龄而异。婴儿与环境的相互作用，包括与他人的相互作用，在不同人群中似乎有所不同，这可能会影响婴儿接触微生物，进而影响婴儿皮肤细菌群落的组成。这些发现表明，婴儿期当地环境导致的微生物接触差异会影响全身皮肤微生物群的建立，对发育和健康结果具有重要意义。本研究总体上为关于婴儿皮肤微生物群的稀少文献做出了贡献，特别是为实地环境中几乎不存在的关于婴儿皮肤微生物群的文献做出了贡献。虽然微生物群研究通常关注国家层面的模式，但本研究关注人群水平因素，如母亲的社会经济地位和与照顾者的接触，对婴儿皮肤细菌群落的影响。这种方法加强了我们对当地变量如何影响婴儿皮肤微生物群的理解，并为进一步的研究铺平了道路，这些研究将生物样本采集与问卷调查相结合，以充分了解特定行为如何决定婴儿接触微生物的情况。这一领域的工作对婴儿护理和健康具有重要意义，也有助于研究不同身体部位的微生物群落如何随时间发展，并应用于与皮肤微生物群相关的特定健康结果（如免疫系统发育或特应性皮炎）。
