Babies in America tend to be a lot cleaner than those in, say, Namibia, and that has some advantages—most notably a drastically lower infant mortality rate. But scientists are beginning to wonder if our obsessively sanitary culture has actually given rise to various health issues, they tell the Wall Street Journal . “We have traded one problem for another,” says one Tufts professor. Allergies, asthma, and autoimmune diseases have all risen drastically as we've gotten more hygienic.
Those problems were virtually unheard of in the US a hundred years ago, and remain that way in the developing world—which is overrun instead by infectious diseases that are far more rare here. Now, some scientists are seeing if they can harness the healing properties of the harmless microbes our filthier selves might encounter. Clinical trials are testing out pig whipworm as a treatment for peanut allergies, Crohn's disease, and more—and so far, the results are promising. (More clinical trials stories.)