Do I have different microbes on different parts of my skin?

Yes! It would be short sighted to think of skin as uniform. Skin has microclimates … the tropical jungles of the armpits or groin areas are not very similar to the exposed deserts of the forearm and we shouldn’t expect to find the same microbial species in these niches.

You have different skin ecosystems on your body. From a microbe’s perspective the skin can be broadly broken into three habitats… dry, moist and oily. A bit like a coral reef, a rainforest and a savannah. Different species of microbes flourish in different conditions. The microbes that dominate your dry forearm are different from the ones that occupy a much oilier forehead or nose.

Moist sites (e.g. armpit)

  • Most common microbe: Corynebacterium
  • High diversity
  • Most unstable over time

Oily sites (e.g. face, chest, and back)

  • Most common microbe: Propionibacterium acnes
  • Low diversity
  • Most stable over time
  • Also support Demodex mites and Malassezia

Dry areas (e.g. forearm)

  • Mixed makeup – Proteobacterium and Bacteroidetes are more dominant – lower overall load
  • Most diverse
  • Relatively stable over time

The foot ecosystem is again an entirely different ecosystem due to its distinct differences from the microbiome in other areas of the skin.