My sensitive skin diary

Me, Myself and My Microbiome

It’s a pep talk classic. A universal strategy for every social challenge. Just be yourself. Good advice, but based on a shaky assumption: that there’s just 1 you… When in reality, you’re about as plural as can be! The truth is you co-habit your body with trillions of microorganisms. The name for the sum total of this vast population? Your microbiome.

The microbiome: Redefining what it means to be human…

All it takes are a few hard-hitting facts from the Human Microbiome Project to appreciate just how much company we keep, even in our most solitary moments:

  • The human body contains 10 times more bacteria than it has cells
  • More than 50% of our DNA is bacterial in origin
  • Over 500 different species have been isolated on skin alone

… And how we think about the skin

And the skin is home to its own specific population. In fact, every cm2 of skin harbors a billion microbes – bacteria, viruses, fungi and even mites – which live in every layer of skin and even in our subcutaneous fat. There’s no denying it: microbial growth is deeply embedded in and on our bodies. It defines and informs the very nature of our being.

The human: a walking colony

Like a giant anthill, our bodies are, in fact, collectives of organisms, each playing its part in maintaining the health of the whole. The sensationalist view that “bugs are bad” stemming from Victorian times belongs in history books, not daily care routines. If we start with the human side of the bargain: each of the environments forming our body’s many richly populated “landscapes” actively renders itself hospitable to its countless guests. The skin, for example, provides moisture and warmth, as well as trace elements and carbon and nitrogen sources to keep its resident hoards happy. In return, our in-dwelling microbes perform countless functions to keep their homes healthy.

  • In the gut, bacteria produce vitamins, aid in digestion and regulate the immune system.
  • At the skin’s surface, bacteria secrete targeted molecules to attack pathogenic species and prevent their colonizing the skin.
  • They also provide a physical barrier against irritants and allergens, as well as interacting with your skin’s own immune system to dampen inflammation and excessive reactivity.
The time has come to embrace the diverse entity that is you. Take care of your bacteria and they might just return the favor!

1 The NIH HMP Working Group et al. Genome Res. 2009;19:2317-2323
2 The Role of Cutaneous Microbiota Harmony in Maintaining a Functional Skin Barrier Hilary E. Baldwin, Neal D. Bhatia, Adam Friedman, Richard Martin, Sophie Seité