Environmental Contamination in Paleofecal Analysis: why soil sampling is vital for establishing ancient microbial diversity. Environmental Contamination in Paleofecal Analysis

Our study is a demonstration that it is possible, and indeed vitally important, to differentiate between the microbiota found in coprolites and the surrounding soil environment in which they were found in order to accurately portray the microbiome of an ancient sample. Ancient DNA from humans and the gut microbiome found in paleofecal material recovered from the Boomerang Rock Shelter site in southeastern Utah were analyzed and compared to the microbiome from the surrounding sediment. 16S NGS sequencing was used to develop profiles from paleofeces, as well as the particular stratigraphic soil layer from which the paleofeces was recovered. This research demonstrates that it is possible to obtain information about the ancient gut microbiome and differentiate it from the soil microbes, but future analyses should attempt to sequence both in order to ensure that cross-contamination has not occurred.

本研究证实，区分粪化石（coprolites）中检出的微生物群与其出土的周边土壤环境，不仅具备可行性，且至关重要；唯有通过此类区分，方能精准还原古代样本的微生物组（microbiome）。本研究对从美国犹他州东南部回旋镖岩棚遗址（Boomerang Rock Shelter site）出土的古粪便样本（paleofecal material）中提取的人类古DNA与肠道微生物组进行了分析，并将其与周边沉积物的微生物组进行比对。研究采用16S下一代测序（16S NGS sequencing）技术，分别构建古粪便样本以及古粪便出土的特定地层土壤层的微生物组特征谱。本研究证明，可获取古代肠道微生物组的相关信息，并将其与土壤微生物区分开来；但未来的分析应尝试对二者同时开展测序，以确保未发生交叉污染。