Skin Safari – and all that lives on it

When you look closely at the back of your hand, what do you see? In real terms, it’s like staring at the earth as you fly in an aeroplane, 30,000 feet above. You can’t see everything without a powerful microscope, but on the surface of Earth and on the surface of your skin, there’s all sorts of things happening, so let us try and explain some of it.

If it was possible to zoom in on the terrain of our skin, you would enter a strange, exciting world containing diverse populations of microorganisms. Indeed, on the two square metres of our skin, there are more that 1,000 different species of bacterium, not to mention, fungi, viruses and mites. Many are friendly and will do no harm to us, but not all are providing benefit. These are known as pathogenic bacteria and are actively malicious.

This community of the good, the bad and the ugly live with us in what’s known as the skin microbiome, but it’s only since the 2012 Human Microbiome Project that we were able to establish the micro-organisms in us and on us. Counting the numbers of them is an impossible task and a bit like counting the sand grains on the seashore. With estimates between thirty-nine and one hundred trillion it’s a huge number of them. But the fact is that they are there and they exist and they influence our health.

Human skin has a number of different habitats and the warm, swampy areas between the toes are totally different to the dry skin on legs and the oily skin on our scalp. One skin disease that erupts on the slippery, oily habitat of the face, is acne. Many factors cause its condition. The bacterial microbes live in the dark, dingy sewers of pores and hair follicles where they feed off sebum (skin oils) and dead skin that falls down into the pores. They are usually harmless, but everything changes when the hormones of puberty kick in.

It’s a common misconception that blackheads are formed by environmental dirt filling our pores – and are a lack of cleanliness. In fact, they form when dead skin cells and sebum block the top of the pore and are exposed to oxygen in the environment. This causes a chemical reaction that turns the gunk a grey-black colour and in this dark, low-oxygen environment the acne population booms.

One of the more unpleasant predators of our skin wildlife is staphylococcus aureus. It resides on the skin and on the mucous membrane in the nose. Probably a reason why in this current Covid-19 pandemic it is ever-more important that you don’t touch your nose and other parts of yourself, especially any parts of the skin-barrier that may be compromised.

The make-up of our skin’s microbiome also influences the health of our skin. Starting at the very beginning of life, there is evidence that even the way that we are born, whether naturally or by caesarean-section, could determine our future skin and gut microbiomes. The pioneer species from the mother are transferred in natural birth and become the dominant organisms of the skin, making it hard for other bacteria to later gain a foothold – and may be the reason why C-section babies appear to have an increased risk of developing allergies in later life. That is a subject of discussion far too complex for this little paper, but it is yet another example of the animal-life on our skin.

Thankfully all of this changes as our skin microbiome largely stabilises as we reach adulthood. However, the fact is that adulthood allows that in close contact, couples share microbial similarity, with the largest similarity being on their feet. Even office workers can be traced to where they worked by inspecting their skin microbiome. Think of the millions of microbes that cling to flakes of our shedding skin in a confined office, or hands that grab a pole of a subway train and you can see how easily in London it can be described as our ‘fellow passenger’.

In our developed world these days, we have (mostly) incredibly high-levels of hygiene and children are far less exposed to infectious agents as they would have been a hundred years ago. This is great news when it comes to infectious diseases, but a lack of exposure to bacteria in early life may (may according to some sources) in fact impair the development of the immune system – and in particular the immune intolerance – the ability of our immune system to hold itself back and remain unresponsive to substances that are harmless or belong to your own body. This subject alone is worthy of a discussion paper by those far more expert than we are to comment. We will leave it to them to discuss.

Indeed, our skin-safari is a wondrous thing.

Next week, we will continue with our exploration of the skin and more of its complexities. In the interim, keep safe and of course, be regular  with your hand-washing, and don’t touch your face or nose or eyes.

With best wishes

Jim & Sheila and the team at SkinLikes

May 2020