Department of Anthropology, Northwestern University, Evanston, Illinois, USA.
Division of Biological Sciences, University of California San Diego, La Jolla, California, USA.
Am J Hum Biol. 2022 Jan;34(1):e23584. doi: 10.1002/ajhb.23584. Epub 2021 Mar 1.
The skin, as well as its microbial communities, serves as the primary interface between the human body and the surrounding environment. In order to implement the skin microbiome into human biology research, there is a need to explore the effects of different sample collection and storage methodologies, including the feasibility of conducting skin microbiome studies in field settings.
We collected 99 skin microbiome samples from nine infants living in Veracruz, Mexico using a dual-tipped "dry" swab on the right armpit, palm, and forehead and a "wet" swab (0.15 M NaCl and 0.1% Tween 20) on the same body parts on the left side of the body. One swab from each collection method was stored in 95% ethanol while the other was frozen at -20°C. 16S rRNA amplicon sequencing generated data on bacterial diversity and community composition, which were analyzed using PERMANOVA, linear mixed effects models, and an algorithm-based classifier.
Treatment (wet_ethanol, wet_freezer, dry_ethanol, and dry_freezer) had an effect (10% explanatory power) on the bacterial community diversity and composition of skin samples, although body site exhibited a stronger effect (20% explanatory power). Within treatments, the collection method (wet vs. dry) affected measures of bacterial diversity to a greater degree than did the storage method (ethanol vs. freezer).
Our study provides novel information on skin microbiome sample collection and storage methods, suggesting that ethanol storage is suitable for research in resource-limited settings. Our results highlight the need for future study design to account for interbody site microbial variation.
皮肤及其微生物群落是人体与周围环境之间的主要界面。为了将皮肤微生物组纳入人类生物学研究，需要探索不同样本采集和存储方法的效果，包括在野外环境中进行皮肤微生物组研究的可行性。
我们使用双端“干”拭子（右腋窝、手掌和额头）和左侧身体相同部位的“湿”拭子（0.15 M NaCl 和 0.1%吐温 20）从生活在墨西哥韦拉克鲁斯的 9 名婴儿身上采集了 99 个皮肤微生物组样本。每种采集方法的一个拭子保存在 95%乙醇中，另一个拭子在-20°C 下冷冻。使用 PERMANOVA、线性混合效应模型和基于算法的分类器分析 16S rRNA 扩增子测序生成的细菌多样性和群落组成数据。
处理方式（湿乙醇、湿冷冻、干乙醇和干冷冻）对皮肤样本的细菌群落多样性和组成有影响（10%的解释能力），尽管身体部位的影响更强（20%的解释能力）。在处理方式内，采集方法（湿与干）对细菌多样性的影响程度大于存储方法（乙醇与冷冻）。
我们的研究提供了有关皮肤微生物组样本采集和存储方法的新信息，表明乙醇存储适用于资源有限的环境中的研究。我们的结果强调了未来研究设计需要考虑体间微生物变异的必要性。
