Topographical and temporal diversity of the human skin microbiome

Abstract

Human skin is a large, heterogeneous organ that protects the body from pathogens while sustaining microorganisms that influence human health and disease. Our analysis of 16S ribosomal RNA gene sequences obtained from 20 distinct skin sites of healthy humans revealed that physiologically comparable sites harbor similar bacterial communities. The complexity and stability of the microbial community are dependent on the specific characteristics of the skin site. This topographical and temporal survey provides a baseline for studies that examine the role of bacterial communities in disease states and the microbial interdependencies required to maintain healthy skin.

Fig. 1

The 20 skin sites and associated microbiota are representative of three microenvironments: (A) sebaceous, (B) moist, and (C) dry. The relative abundance of the most abundant bacterial groups associated with each microenvironment is depicted for each healthy volunteer. Superscripts indicate phylum: 1, Actinobacteria; 2, Firmicutes; 3, Proteobacteria; 4, Bacteroidetes.

Fig. 2

Median diversity of sites as measured by the Shannon Diversity Index. Error bars represent median absolute deviation. See fig. S1 for key to site codes displayed on the x axis.

Fig. 3

Longitudinal stability of the skin microbiome. A higher number corresponds to greater shared community membership or structure over time. Sites with an asterisk below the site code retained significant community membership over time; those with a bullet retained significant community structure over time, as compared to interpersonal variation at the same site (P ≤ 0.05). Parentheses around asterisks or bullets indicate that significance was achieved for that site when the outlier (volunteer 2) was removed from the analysis. See fig. S1 for key to site codes.