• From The Saturday Evening Post
We are vastly, ridiculously, hopelessly, humblingly outnumbered: For every one human cell, there are an estimated ten single-cell microbes in us or on us, at least 100 trillion in all, nestled in our guts and in our urogenital tracts, lying on our skin and happily ensconced in our mouths and noses—entire civilizations of fungi, protozoa, and (mostly) bacteria that eat, breathe, evolve, reproduce, and die.
Before you reach in horror for the hand sanitizer or industrial-strength mouthwash, keep this in mind: A profusion of research in just the past five years is showing that our microbial hitchhikers, collectively called the human microbiota (and so small that they account for only 1 or 2 percent of our body weight), play a key role in maintaining…