As I type these words at my desk, I’m seeding my house with bacteria. I touch the desk, the light switch, the coffee mug, and the microbes on my hands now coat these objects. I absent-mindedly swish my foot across the floor, and I leave microbes there too.
I scratch my head, ejecting a cloud of microbes into the air. You do this too. We all do. We constantly sign the places around us with the microscopic parts of ourselves.
Our bodies are home to trillions of microbes, which outnumber our own cells by at least a factor of three. They and the genes they contain are collectively known as the microbiome, and they influence our lives, health, minds, and more. But the microbiome isn’t confined to our skins. It extends into the world around us.
“You have this continual outreach from your body into the environment,” says Jack Gilbert from the University of Chicago. “You are bleeding microbes into space. It’s the first thing anyone will interact with you on.”
Gilbert has been studying this extended self through the Home Microbiome Project—an initiative to map the microbial character of our homes. The first results are out today, and they show just how quickly our microbes colonise the spaces around us. They also show that these traces can be used as forensic tools, to show whether we stayed in a certain place and how long ago we left.
Read the full, original story: When you move house, your microbial aura moves too