Parents make their baby is . Parents do their to keep dirt away from . However, a scientist says dirt makes babies . Dr Jack Gilbert did research into dirt, and children. His is in a . He said: "It's fine to wash their ….but if a dog licks their , that's not a bad ."
Dr Gilbert said babies should get . Dirt helps babies to fight . Children get allergies or because parents clean too much. This makes children's bodies . Gilbert likes the "five-second ". This is when you eat that fell on the for fewer than five .