The following Mark's Daily Apple article was written by Marxist and is narrated by Brock Armstrong.

What's living on your skin?

The average human body has about 1.2 square meters of skin.

Scattered across and nestled in its myriad crevices and canyons would lie trillions of bacteria,

bungi, viruses, and mites. Before you shudder and reach for the bleach and a stiff scouring brush,

remember the importance of cultivating and

supporting the billions of bacteria living in your gut. Recall the vital roles they play that we know

about in our health and realize that the skin microbiome isn't any different. Although research is young, we are learning that the critters living

on our skin who number in the billions per centimeter of skin are supposed to be there. And even though

we don't know exactly all they're doing, we know this. The skin microbiome isn't an artifact of civilization or agriculture.

We've always hosted colonies of microbes on our bodies and we've evolved in the context of a skin microbiome.

Since our current environment is more sterile than any preceding it, our ancestral skin microbiome was almost certainly more diverse.

We must exercise caution then when trying to extirpate our skin of germs.

The composition of our skin microbiome varies between areas of the body.

Your left hand, for example, has a markedly different

microbial community than your right hand. Like the gut bacteria, our skin bacteria performs important

roles. It's possible, maybe even probable, that the fungi, viruses, and mites living on our skin are also necessary, but we simply

don't know enough about these critters to say for sure. So today, we'll focus mainly on how

the bacteria living on our skin impact us. They regulate the skin-level immune response to

allergens.

For instance, in adolescence, the presence of acinotobacter bacteria on the skin was associated

with the expression of anti-inflammatory molecules and protection against allergic reactions.

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