Sample Collection, DNA Extraction, and Library Construction Protocols of the Human Microbiome Studies in the International Human Phenome Project

The human microbiome plays a crucial role in human health. In the past decade, advances in high-throughput sequencing technologies and analytical software have significantly improved our knowledge of the human microbiome. However, most studies concerning the human microbiome did not provide repeatable protocols to guide the sample collection, handling, and processing procedures, which impedes obtaining valid and timely microbial taxonomic and functional results. This protocol provides detailed operation methods of human microbial sample collection, DNA extraction, and library construction for both the amplicon sequencing-based measurements of the microbial samples from the human nasal cavity, oral cavity, and skin, as well as the shotgun metagenomic sequencing-based measurements of the human stool samples among adult participants. This study intends to develop practical procedure standards to improve the reproducibility of microbiota profiling of human samples.