Our skin, the largest organ in the human body, is also a habitat for millions of microscopic inhabitants - microorganisms like bacteria, fungi, and viruses. However, this doesn’t mean they are all bad. Microorganisms on our skin play a vital role in combating invading pathogens, training our immune system, and decomposing natural products (i.e., proteins, lipids, and carbohydrates on the surface of the skin). This is similar to the role played by microorganisms in our gut.
The global scientific community has focused on these skin microbial species due to their close connection to our health. However, comprehensively identifying these minuscule yet crucial creatures through sequencing has not been feasible due to their low biomass - until now.
In a recent study, BGI-Research successfully employed its proprietary ultra-low biomass metagenomic sequencing method to perform high-depth sequencing on 450 human facial samples. By integrating the sequencing data with 2,069 publicly available skin microbiome datasets, the research team established a nearly complete catalog of skin microbial genomes, termed the Unified Human Skin Genome (UHSG). These research findings are published in Advanced Science.
The study “Integrated Human Skin Bacteria Genome Catalog Reveals Extensive Unexplored Habitat-Specific Microbiome Diversity and Function” is published in Advanced Science.
The UHSG comprises a total of 813 prokaryotic species and 5,779 metagenomic assembly genomes from 22 different skin sites, encompassing 470 new species across 20 phyla, along with 1,385 new assembly genomes.
Building upon the UHSG, researchers were able to explain the core functions of the skin microbiome and identified variations in amino acid metabolism, carbohydrate metabolism, and drug resistance functions across various phyla. This discovery of drug-resistance traits within the skin microbiome will contribute to the appropriate use of antibiotics for skin-related health conditions.
The study also uncovered a potential protective mechanism of the skin. It reveals that under sebum-rich and humid conditions, conditional pathogenic bacteria on the skin decrease the likelihood of generating more toxic strains.
The conditional pathogenic bacteria only exhibit pathogenic behavior under specific conditions, such as a wound that provides access to the bloodstream or a decline in immune function.
Moreover, analysis of secondary metabolites from the UHSG led to the identification of 1,220 putative novel secondary metabolites, several of which were present in previously unknown genomes. The study of secondary metabolites may contribute to drug discovery, pest control, as well as environmental remediation.
The UHSG serves as a valuable reference database that will facilitate a deeper comprehension of the role of skin microorganisms in the future. It also highlights that certain species within the UHSG display resistance to particular drugs, carrying significant implications for treating skin-related diseases.
The outcomes of this study bear substantial scientific importance and offer potential clinical applications. Research on the skin microbiome will enhance our grasp of the interplay between skin health and diseases, concurrently guiding the development of innovative skincare products.
Dr. Nie Chao, co-corresponding author of the study and Director Scientist of BGI-Research, said, "This research unveils the immense potential of the human skin microbiome, offering new avenues for future investigations. As our understanding of the human microbiome deepens, research on the human skin microbiome will continue to achieve further breakthroughs, affording us improved health protection and disease treatment strategies in the future."
This study underwent ethical review and adheres to regulations, and privacy protocols.
Read the article: https://onlinelibrary.wiley.com/doi/10.1002/advs.202300050