In this study, I use microbiome datasets from global soil samples and diverse hosts to learn whether soil microbial taxa are found in host microbiomes, and whether these observations fit the narrative that environmental interaction influences human microbiomes. A major motivation for conducting host-associated microbiome research is to contribute towards understanding how the environment may influence host physiology. The microbial molecular network is considered a key vector by which environmental traits may be transmitted to the host. Research on human evolution seeks evidence that can inform about the living experiences of human ancestors. This objective is substantially enhanced by recent work on ancient biomolecules from preserved microbial tissues, such as dental calculus, faecal sediments and whole coprolites. A challenge yet is to distinguish authentic biomolecules from environmental contaminants deposited contemporaneously, primarily from soil. However, we do not have sound expectations about the soil microbial elements arriving to host-associated microbiomes in a modern context. One assumption in human microbiome research is that proximity to the natural environment should affect biodiversity or impart genetic elements. I present evidence supporting the assumption that environmental soil taxa are found among host-associated gut taxa, which can recapitulate the surrounding host habitat ecotype. Soil taxa found in gut microbiomes relate to a set of universal ‘core’ taxa for all soil ecotypes, demonstrating that widespread host organisms may experience a consistent pattern of external environmental cues, perhaps critical for development. Observed differentiation of soil feature diversity, abundance and composition among human communities, great apes and invertebrate hosts also indicates that lifestyle patterns are inferable from an environmental signal that is retrievable from gut microbiome amplicon data.

This article is part of the theme issue ‘Insights into health and disease from ancient biomolecules’.

在这项研究中，我使用来自全球土壤样本和不同宿主的微生物组数据集来了解是否在宿主微生物组中发现了土壤微生物分类群，以及这些观察结果是否符合环境相互作用影响人类微生物组的说法。进行宿主相关微生物组研究的一个主要动机是有助于理解环境如何影响宿主生理。微生物分子网络被认为是环境特征可以传递给宿主的关键载体。对人类进化的研究正在寻找可以为人类祖先的生活经历提供信息的证据。最近对来自保存的微生物组织的古老生物分子的研究大大增强了这一目标，例如牙结石、粪便沉积物和整个粪便。一个挑战是区分真正的生物分子与同时沉积的环境污染物，主要来自土壤。然而，我们对现代环境中到达宿主相关微生物组的土壤微生物元素没有合理的期望。人类微生物组研究的一个假设是，接近自然环境会影响生物多样性或传递遗传元素。我提供了支持环境土壤分类群存在于宿主相关肠道分类群中的假设的证据，这可以概括周围的宿主栖息地生态型。在肠道微生物组中发现的土壤分类群与一组适用于所有土壤生态型的通用“核心”分类群有关，这表明广泛的宿主生物可能经历一致的外部环境线索模式，这可能对发展至关重要。

这篇文章是主题问题“从古代生物分子洞察健康和疾病”的一部分。