McConchie on Bioethics writes:
Remember the doctor that recommended that you eat your snot? Well now two epidemiologists are claiming that the more kids bathe in dirt, the less likely they are to eczema. Under their theory, humans have learned to live with certain bacteria over the past few million years and actually now need them. Without the bacteria to keep them occupied, the body's two types of immune system cells attack the body for want of an opponent. The researchers believe that this helps point out that moderhygienene may actually promote allergic diseases.
Actually, the study seemed to me to be saying that if you have cats, multiple kids, or a farm then you're less likely to have eczema, asthma, or other allergic reactions, but the conclusion Daniel draws isn't too much of a stretch from that. So bring on the dirt baths. I assume dirt eating is part of this.