The Microbiome and Your Skin

The Microbiome and Your Skin

Imagine sitting in a room, with nobody else around. You may enjoy the peace of solitude for a few moments, but are you truly alone? It turns out that you and I - and everyone else - have millions upon millions of microorganisms living and thriving in and on our bodies. Unlike the gut microbiome which has been studied for many years, the research on skin and scalp microbiome has only recently gained steam. But is slathering yogurt on your skin worth the hype? A closer look into the microbiology of skin will shed light on the billions of residents and tourists that occupy our skin and affect its structure and function.

You may have heard the term ‘microbiome,’ but what does it really mean? Firstly, ‘genome’ refers to the complete set of genes in an organism. Each genome contains all of the information needed to build and maintain that organism. In humans, a copy of the entire genome (think of it like your blueprint) is contained in all cells that have a nucleus. The microbiome is defined as the collective genome of microorganisms; the ‘skin microbiome’ is the genome of all the microscopic organisms present on the skin. So what do we call the little critters themselves? Microbiota. The skin microbiota includes 1) resident microorganisms (the residents) and 2) transient microorganisms (the tourists) which come along from the environment and hang around from hours to days. The residents are typically beneficial but both are non-pathogenic (do not cause disease) under normal conditions. It’s important to understand that we are not only speaking about bacteria. Microbiota can also include yeasts, viruses and fungi.

The Landscape

Each microbial community is as diverse as its host – and the geography where they live is linked to the type of microbe that thrives there. The communities found in the underarms is vastly different than that of the forehead or palm. Moist regions like the navel or Axilla Harbor Corynebacterium and Staphylococcus species. Oily sites have lipid-loving species such as Propionibacteria (think P. acnes) which has adapted to this lipid-rich, anaerobic environment. In dry sites, a mixed bacterial population seems to reside. Within these sites, the types of microorganisms also varies. The underarms have a large bacterial diversity and we can often smell their work during a sweaty session. The forehead, on the other hand, seems to favor colonization of P. acnes preventing other microorganisms from populating the area.

The term pro-biotic means ‘for life.’ It refers to microorganisms that deliver a health benefit to the host. It could be a bacterium or even a type of fungus or yeast. Walking into any supermarket these days, you’d be hard-pressed to find a dairy section without probiotic drinks and yogurts lining up the shelves. Due to scientific understandings, we know there are some beneficial bacteria that will promote a healthy gut. But what about a healthy skin?

Microbial Skin Care

The idea of providing probiotics directly to skin to improve health conditions is not far-fetched. However it is challenging up to this day. First is keeping them alive (microbes are alive, after all). Second is the nature of the skin ecosystem. In a healthy state, skin tends to resist microbial colonization. While technological advances may help formulators overcome these obstacles, there is much work to be done for a safe and effective solution. There is another side to the microbe coin that could yield results even today – prebiotics.

Pre-biotics are basically the food for the probiotics, they fuel probiotics. Prebiotics stimulate the growth of the good guys, and together prebiotics and probiotics rebalance the bacterial community. In our diet, we find them as carbohydrates and fiber (think beans and legumes). For the little guys, they are simple structures like oligosaccharides and sugars that nourish beneficial bacteria and prevent overgrowth of pathogens. If probiotics starve, then pathogens may grow can cause inflammation or an imbalance. In skincare, prebiotics can also help enhance the skin’s immune response, making these an integral part of healthy, resilient skin.

REFERENCES

Dréno, B., et al. (2016), Microbiome in healthy skin, update for dermatologists. J Eur Acad Dermatol Venereol, 30: 2038–2047.
Al-Ghazzewi, FH, & Tester, RF (2014), Impact of prebiotics and probiotics on skin health. Beneficial microbes, 5(2), 99-107.
Stokes JH, Pillsbury DM (1930), The effect on the skin of emotional and nervous states III. Theoretical and practical consideration of a gastro-intestinal mechanism. Arch Derm Syphilol.;22(6):962-993.