Human Microbiome Project

In the current issue of Maclean’s, I wrote about a global effort to track all the bacteria that live in the human body—a monumental undertaking, since they outnumber our own cells by ten-to-one. It may gross people out to think we’re literally crawling with bugs, but a growing body of research suggests they’re crucial to our health: by now, microbes have been implicated in everything from periodontitis, to obesity, to premature labour.