As soon as we are born, bacteria move in.

Our bodies harbor 100 trillion bacterial cells, outnumbering our human cells 10 to one.

It’s also been easy for science to overlook their role in our bodies and our health.

the emerging science of human-microbe symbiosis has an even greater implication. “Human beings are not really individuals; they’re communities of organisms

It’s not just that our bodies serve as a habitat for other organisms; it’s also that we function with them as a collective

To find a biological answer to the question “Who are we?” we might look to the human genome.

Now comes the notion that the genomes of microbes within us must also be considered. Our bodies are, after all, composites of human and bacterial cells, with microbes together contributing at least 1,000 times more genes to the whole

Indeed, several scientists have begun to refer to the human body as a “superorganism” whose complexity extends far beyond what is encoded in a single genome.