"Years ago, impelled in part by their oldest daughter’s constipation problems, the Sonnenburg family revamped its diet. They threw out all processed food-stuffs, and began eating plenty of veggies and whole grains. They bought a dog. Justin Sonnenburg began hand-milling his own wheat berries for bread. He took up gardening. And when he compared his archived microbes from years ago with recent ones, he discovered that his microbial diversity had increased by half. “That’s a huge difference,” he told me, “as big as the difference between Americans and Amerindians.”"