Children who grow up on farms and/or have pets tend to be less likely to have allergies, and I think asthma is more common among people who grow up in homes with greater cleanliness, but I’m not sure whether that’s down to the products used or to the lack of healthily challenging bacteria. I recently read with a certain amount of surprise and horror about what can be carried into the home from outside on the soles of shoes (ecoli for example), as a kid we weren’t consistent in taking shoes off in the kitchen before going into the rest of the house.