From the ‘Sci­ence proves mum right’ and ‘Obvi­ous, but still needs to be stated’ file comes the news that chil­dren who are exposed to bac­te­ria, viruses, worms, and dirt have health­ier immune sys­tems.

Pub­lic health mea­sures like clean­ing up con­t­a­m­i­nated water and food have saved the lives of count­less chil­dren, but they “also elim­i­nated expo­sure to many organ­isms that are prob­a­bly good for us.”

“Chil­dren raised in an ultr­a­clean envi­ron­ment, […] are not being exposed to organ­isms that help them develop appro­pri­ate immune reg­u­la­tory circuits.”

Of course there are caveats, or at least com­mon sense rules (although even the researchers in this field are debat­ing exactly how far to take this):

“I cer­tainly rec­om­mend wash­ing your hands after using the bath­room, before eat­ing, after chang­ing a dia­per, before and after han­dling food,” and when­ever they’re vis­i­bly soiled, [one researcher] wrote.

Dr. Wein­stock goes even fur­ther. “Chil­dren should be allowed to go bare­foot in the dirt, play in the dirt, and not have to wash their hands when they come in to eat.”

via Kot­tke