His answer is somewhat surprising. “Rather than trying to make our food and water even cleaner,” Sepkowitz proposes, “we should focus instead on making sure it’s dirty enough to assure our good health.” This idea runs counter to most of the wisdom accumulated over the past several millennia, but I’m all about it. After all, why are so many of us newly allergic to formerly innocuous foods? And what does the effect of not breastfeeding a baby do to its immune system? What kind of havoc does the upsurge in antibiotic use wreak on our bodies? Sepkowitz’s “America the Hygienic” and its “near-bubble babies” are less a triumph and than a disaster waiting to happen.

Perhaps Sepkowitz’s reasoning explains the craze for raw milk, as chronicled in The Sunday Times and the New York Times. Perhaps we’re sick of eating foods that are “hosed and boiled and rinsed and detoxified and frozen” and, increasingly, irradiated.

Sepkowitz’s conclusion is on the weak side, if you ask me—he wants to “fund the boring scientists who focus on untangling the intricacies of the gut’s immune system.” Fine. That works. But in the meantime, I’ll keep eating candy that’s dropped on the floor and grating carrots that haven’t been peeled into my salad. “Our centuries-long program of winnowing out all the muck has turned us into sissies,” Sepkowitz notes. Boo-yah! I’m with him, eating dirt.