CHICAGO (CBS) — Research from the University of Chicago says exposure to germs and bacteria is good for a child’s developing body.

“We’ve become paranoid about the exposure to potentially dangerous organisms,” said Dr. Jack Gilbert, a University of Chicago microbe teacher, as well as a father.

His book, ‘Dirt Is Good,’ concludes that there is some benefit to a not-so clean environment in this age of protective vaccines and sterile homes.

“If you don’t allow your child to experience a rich and diverse microbial world, their immune system becomes lazy,” Dr. Gilbert said. This means cells in a child’s developing body, meant to fight off foreign agents, have nothing to do.

“When they finally see one of these allergens, they can make them over-reactive. And that’s when you get things like food allergies, eczema and asthma,” Dr. Gilbert said.

According to CBS 2’s Vince Gerasole, much of this can be based around common sense. If you’ve been preparing raw meat, or a cold or flu is circulating, make sure to regularly wash your hands. But, he adds, a few dog licks can sometimes go untreated.

“Making sure that they get the right exposure just means allowing them to live their life — to experience the world,” Dr. Gilbert said.