Scientists from Europe and the US used information collected from hundreds of skin swabs to produce the 3D maps of molecular and microbial variations across the body.
They claim these can be used to provide a baseline for future studies of the interplay between the molecules that make up our skin, the microbes that live on us, our personal hygiene routines and other environmental factors.
"This is a starting point for future investigations into the many factors that help us maintain, or alter, the human skin ecosystem -- things like personal hygiene and beauty practices -- and how those variations influence our health and susceptibility to disease," says senior author Pieter Dorrestein, PhD, professor of pharmacology in the University of California San Diego Skaggs School of Pharmacy.
Creating 3D maps
To build their 3D maps as accurately as possible, the team swabbed 400 different body sites of two healthy adult volunteers, one male and one female, who had not bathed, shampooed or moisturised for three days.
Using a technique called mass spectrometry they were able to determine the molecular and chemical composition of the samples, and sequenced microbial DNA in the samples to identify the bacterial species present and map their locations across the body.
The team then used MATLAB software to construct 3D models that illustrated the data for each sampling spot.
Despite the three-day cease on using personal hygiene products, the most abundant molecular features in the skin swabs still came from hygiene and beauty products, such as sunscreen.
Detecting past and present
According to the researchers, this finding suggests that 3D skin maps may be able to detect both current and past behaviours and environmental exposures.
The study also demonstrates that human skin is not just made up of molecules derived from human or bacterial cells, and that plastics found in clothing, diet, hygiene and beauty products, also contribute to the skin's chemical composition.
The maps now allow these factors to be taken into account and correlated with local microbial communities.
The study, published by Proceedings of the National Academy of Sciences, may help further understanding of the skin's role in human health and disease too.
"This is the first study of its kind to characterize the surface distribution of skin molecules and pair that data with microbial diversity," continues Dorrestein.
"Previous studies were limited to select areas of the skin, rather than the whole body, and examined skin chemistry and microbial populations separately."
This research was funded, in part, by the European Union 7th Framework Programme and Science Without Borders Program, National Institutes of Health (grants GM085764, 3-P41-GM103484 and GMS10RR029121), Howard Hughes Medical Institute, Keck Foundation, San Diego Center for Systems Biology.