I admit to not keeping my house sparkling clean all the time (or even most of the time). And we’re big believers in the 5-second rule for food items that drop on the floor–unless the dog gets there first.

But I now have validation–from scientists at Harvard, no less–that a messy house might actually be a healthier house.

Richard S. Blumberg and Dennis L. Kasper and a team of researchers from Harvard Medical School just published a study in the journal Science that found that I’ve been right all along. Well, I wasn’t actually mentioned in the article, but they did find that exposure to germs early in life actually helps strengthen the immune system.

Actually, they said it like this: “These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures.” In English, that means that exposing babies (in this case, mice) to common germs makes the immune system work hard and makes it better able to fight off germs, disease, and other stuff later in life.

Bottom line: We need germs and dirt to keep use healthy.

A number of other scientists are now saying that the reason we’re seeing big increases in asthma, food allergies, and other immune system disease is that little kids aren’t exposed to enough germs. As a result, their immune systems never get any practice fighting off germs, so when a child finally does come in contact with some serious germs, his immune system has no idea what to do. Blame it on the antibacterial soaps, antibiotic cremes, and our general obsession with killing 99.9 percent of germs and keeping our houses spotless.

So stop cleaning so much and start enjoying life a little more.