Advances in genetic research have brought a whole host of new nomenclature to the field of cosmetic science. Since this area of science is new to most cosmetic chemists, here’s a quick primer on the genome, microbiome, and metagenome.
The genome consists of all of an organism’s genetic information encoded in DNA or RNA in the cases of viruses. All the cells in your body have the same DNA, but they can behavior differently from one another due to gene expression, also referred to as gene regulation. Genes code for proteins that are needed for cellular functions. These proteins include biomarkers of skin aging like matrix metalloproteinases, sirtuins, and interleukins. Information about the regulation of these proteins can be used to assess anti-aging properties of ingredients and cosmetic products.
A microbiome is defined as all the microbes and their interactions with each other and their host in a defined habitat. A microbiome has transient and persistent elements. The skin performs many important functions, including the prevention of water loss, regulation of body temperature, protection from environmental insults and immunological functions. The skin’s microbiome contributes to this protective barrier through a variety of mechanisms including the exclusion of transients and pathogens by competing for nutrients and habitat. The skin microbiome also plays a role in many skin conditions including dandruff, acne, dermatitis, and axillary odor.
A metagenome is made up of all genetic elements the host plus all those of all the microorganisms (microbiome) that live in or on that host. Using a metagenomic approach, the Human Microbiome Project was launched in 2008 by the National Institutes of Health. The HMP aims to define five human microbiomes including that of the skin. Future goals of the project intended to identify the role of our microbiome not only disease, but in maintenance of our health. This will certainly bring new insights to cosmetic formulators and may provide direction for future skin care products.