derived from petroleum-based precursors rather than a recent
fermentation event, indicating a synthetic origin. No antimi-crobial peptides were detected.
Wilson Lee, Director of Research and Development at
Estée Lauder Co. and co-author of the kimchi patent, stands by
the antimicrobial activity of fermented radish extract. However,
he told Inform that Estée Lauder does not use the particular
LRRFF source tested in the study. Lee notes that kimchi must
be fully fermented to produce antimicrobial peptides, and that
perhaps the commercial source was not fermented sufficiently.
“Our kimchi is fermented at least 6 months before extraction,”
3D mapping of the
human skin surface
Skin, the largest and most exposed organ of the human body,
is composed of molecules derived from skin cells, microbes,
personal care products, and the environment. Now, for the
first time, researchers have characterized the skin surface dis-tributions of molecules and microbes across the entire human
body (Proceedings of the National Academy of Sciences U. S. A.,
http://dx.doi.org/10.1073/pnas.1424409112, 2015). The
technique may reveal new insights into the complex molecu-lar interactions that take place on the skin surface.
In recent years, scientists have begun to appreciate the
important contributions of the microbiome—commensal
microorganisms living on or within the body—to health and
disease. However, very little is known about how molecules
on the skin surface determine the distribution of microbial
species, how microbes chemically modify skin molecules to
alter the local environment, or how personal care products
influence these interactions.
So an international team of researchers led by Pieter C.
Dorrestein, Nuno Bandeira, and Rob Knight at the Univer-sity of California, San Diego, USA, and Theodore Alexan-drov at the University of Bremen, in Germany, developed an
approach to visualize the chemical and microbial composition
of human skin through the creation of 3D topographical maps.
The researchers swabbed the skin surfaces of one male and
one female volunteer at 400 different body sites. They then
analyzed chemicals at each site using mass spectrometry and
identified microbes by sequencing 16S ribosomal RNA. The
team used MATLAB software to construct 3D models of the
human body to visualize the data obtained at each sampling
site, with a color scale corresponding to the amount of mol-ecule or microbe detected.
By comparing mass spectra to those of known skin mol-
ecules, bacterial products, and personal care ingredients, the
researchers were able to identify about 20% of the detected
chemicals. Although the volunteers did not shower or apply
personal care products for 3 days prior to the sample col-
lection, a large portion of the identified molecules matched
beauty products or cosmetic ingredients, such as surfactants,
polymeric substances, and sunscreens. The researchers say
that this finding reflects “the lasting impact of our beauty and
hygiene products on the molecular composition of the outer-
most layer of skin that is exposed to the environment.”
The researchers detected 36 phyla of bacteria among the
400 body sites, with the most common being Actinobacteria,
Firmicutes, Proteobacteria, Cyanobacteria, and Bacterioidetes.
Topographical mapping showed that different microbes local-
ized to different areas of the body. For example, the family
Staphylococcaceae was found in moist areas, such as the feet
of both volunteers, under the female’s breast and neck, and
around the male’s nose. In contrast, the genus Propionibacte-
rium was found in regions with a high density of sebaceous
glands, such as the head, face, upper back, and chest.
Some molecules spatially correlated with specific bac-teria. For instance, the localization of oleic acid and palmitic
acid mirrored that of Propionibacterium. The researchers
hypothesize that the bacteria produced these lipids by hydro-lyzing human acylglycerides.
This study establishes the feasibility of 3D molecular
mapping of the human skin surface and lays the foundation for
future studies involving additional volunteers. As more human
skin maps become available, scientists could gain a better
understanding of how skin chemistry changes in response to
microbes, personal care products, and environmental factors.
sizing up down-the-drain
Every day people discharge home and personal care products,
pharmaceuticals, and other chemicals to water ways by bathing,
washing clothes, pouring unwanted products down the sink,
or using the toilet. In a recent study reported in Science of the
Total Environment, Katherine E. Kapo and her colleagues at
Waterborne Environmental, Inc. (Leesburg, Virginia, USA)
teamed up with Procter & Gamble (Cincinnati, Ohio, USA)
scientists to estimate levels of down-the-drain chemicals in
rivers and streams on a broad geographical scale ( http://dx.doi.
org/10.1016/ j.scitotenv.2015.02.105, 2015).
The ecological risk posed by chemicals discharged from
wastewater treatment plants is strongly related to the dilution
level of the chemical, which varies by geography, water flow
rate, and the level of the chemical already present in the water-way from upstream wastewater treatment plants. Also, the rate
at which the chemical becomes degraded or volatilized in water
in other words, the in-stream decay rate) influences its dilu-tion level.
When assessing ecological risk over large geographical
scales (for example, the national level), it is more informative
to provide ranges of exposure levels, rather than a single average
value or worst-case scenario. So Kapo and her colleagues used a
web-based tool developed by the American Cleaning Institute
(iSTREEM®; Washington, DC, USA) to estimate distributions
of dilution factors and per capita wastewater generation at the
national level. The analysis was not specific to any one chemi-cal, but was instead applicable to all down-the-drain chemicals.
The iSTREEM model incorporates data from more than
10,000 wastewater treatment plants and 1,700 intake sites of
drinking water treatment facilities, covering more than 200,000
river miles. Using these data, iSTREEM can provide an esti-mated concentration of a chemical at a particular sampling
point along a waterway.