Authors of a new book suggest that children need to be allowed to get dirty in order to gain access to certain microbes that they say are necessary to develop a healthy immune system.
Authors B. Brett Finlay and Marie-Claire Arrieta argue in their new book "Let Them Eat Dirt: Saving Your Child from an Oversanitized World" that allowing children to get dirty will expose them to healthy germs that will actually help them in the long-run.
"If we miss out on that exposure, the immune system is not going to mature," Arrieta, an expert in microbes and immunology, said in an interview with ABC News.
The authors go on to say that children who do not fully develop their immune systems are at higher risk for asthma, diabetes, and obesity.
Finlay and Arrieta say that while killing bad microbes has led to less death from infections, scientists are beginning to discover that good microbes are being killed at the same time. As a result, children end up with "western society diseases" such as allergies, obesity, and diabetes.
They say microbes, which we are born without, are essential for the maturation of our immune systems. If we do not get all of the microbes we need, the immune system becomes underdeveloped and cannot do what it is supposed to, the pair write for The Wall Street Journal.
Finlay and Arrieta suggest that playing in dirt is the best way for children to get the microbes they need. They go on to say that while children, especially those under the age of five, should be allowed to be play in the dirt, there still need to be limits.
"We do have to think a bit: let the kid lick the floor in your own house but not the subway station," Finlay, a microbiology professor at the University of British Columbia in Canada, said.
They state that while there is no evidence that infectious diseases help to improve humans, there needs to be a balance between the risk of exposing children to good microbes and the risk of exposing them to infections.
The authors suggest that it is perfectly alright for parents of newborn babies to allow others to touch their child, and it is also okay to let the family dog lick their children.
"A dog will come and lick you and your kids. That's good," Arrieta said. "They are basically bringing in the outdoors into your home."
The authors also suggest that in the event a pacifier falls on the floor, it does not need to be washed off, nor do children need to wash their hands after they have played outside.
"Put it in your own mouth â¦ don't wash it. Studies show that's beneficial in reducing asthma and obesity" in children, Finlay said.
However, not everyone agrees with their findings. Melissa Willets, a mother of three and a self-described germophobe, said that while kids should not grow up in a bubble, parents inherently want to protect their children from germs.