I was at family BBQ last weekend when my eight-month-old niece plucked a piece of grass and stuck it in her mouth. I watched to make sure she didn't choke, but I didn't freak and fish it out of her mouth.

For as long as I can remember my mom and grandma have told me how important it is to let babies and kids get dirty and that "a little dirt never hurt anyone." They explained that the immune systems of kids needs a chance to build up and if you're chasing babies and kids wiping them with sanitizer every second, their little bodies won't be able to build up the resistance against germs that they need.  Turns out mom and grandma were right.

A new study published in the Journal of Allergy and Clinical Immunology says that  babies who are exposed to pet hair, household germs, and dirt are less likely to develop allergies, asthma, or other breathing problems as they get older.

Researchers found that babies who were raised in houses with mouse hair, cat hair, and cockroach droppings (not that it's reccommended you let your cockroach problem go untreated!) in the first year of their lives have lower rates of wheezing by three years old. On the other hand, babies who are not exposed to these allergens end up having higher rates of wheezing.

So before you yank that piece of grass out of your baby's mouth, keep in mind that a couple germs here and there never hurt anyone, and in fact, could actually be healthy.