Moms want the best for their children. And we all want to protect them from harm. The boom in bottled water is testament to that. Before, we'd only boil tap water for their ees, now people boil mineral or distilled water. Some even buy the Dr. Edward's kind that costs twice for the same amount.
Unfortunately, too much of a good thing can be too much as well. Nobody wants diarrhea to serve as a colon cleanser to tots who don't need one but some of those who grow up with super sterile evrything end up being hit the worst by common germs. So easing your child into less sterile stuff may do him good. I don't mean parents should feed them mice droppings and the like, but easing them into plain mineral water (or even tap water if it's proven safe) and introducing foods prepared in different ways can be a start. Also, at a certain point, ease up on disinfecting his toys with alcohol. And do allow them to play in the sand.