It seems like common sense to most parents to make sure their baby is always a clean place. Most parents do their best to keep dirt and bacteria from their little ones. However, a scientist says dirt is an important part making babies stronger. Dr Jack Gilbert the University Chicago studies the ecosystems bacteria. He did research how dirt and bacteria affect children. He published his research a book called 'Dirt is Good: The Advantage Germs for Your Child’s Developing Immune System'. He told America's NPR news station that: "It's fine to wash their hands if there's a…flu virus going , but if they're interacting a dog and the dog licks their face, that's not a bad thing."
Dr Gilbert wrote that letting children get dirty was largely beneficial. Exposing small kids to dirt helps them to build their immune system. Dr Gilbert even argues that children often get allergies because parents try to protect their kids too much and try too hard to clean everything that children use. He said parents now over-sterilize everything the home. This causes children's immune systems to become too sensitive, which can lead to things like asthma, eczema, and food allergies. Gilbert even defended the "five-second rule". Many people think it is OK to eat something that fell the floor fewer than five seconds. Gilbert says it is OK to eat something that fell the floor as long as the floor isn't really dirty.