You are a walking ecosystem. And you are not alone. Ever. Microbial life teems on, and in, your body. If you’re healthy, these life forms live in harmony with you in a stable and balanced system, where host and guest alike contribute to the rhythm and hum of a cooperative community.
Humans and microbes have coevolved to a point of mutual benefit—we need each other. The number of microbial cells in our bodies outstrip the number of human cells by about ten to one. And while the human genome contains approximately 30,000 genes, the microbial genome, the microbiome, is made up of more than four million genes. We are more “them” than “us.”
There’s a growing interest in studying the ecosystem that is the human microbiome, and it’s more than a research trend. It may herald a shift in how we think about human health and medicine and our place in the natural world.