The Current

Kids need to get dirty to ward off disease, says microbiologist

If the idea of the germs on objects that get ingested into your child's gullet makes you queasy then you need to hear B. Brett Finlay extol the power of microbes. The microbiologist says kids could use more dirt in their lives and even in their mouths.

What is the most disgusting thing your child has tried to eat?

8 years ago
Duration 1:05
What is the most disgusting thing your child has tried to eat?

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You watch a child pick up a blob of gum off a dirty street and cringe at the sight of it being plopped in their mouth and chewed for the second time.

What makes a scenario like this worse — that child is yours.

But before you freak out about the microbes your kids may be ingesting, says UBC microbiologist B. Brett Finlay, you should know many of the bugs are actually good for them.

"We're finding these microbes help our bodies train the immune system," Finlay, co-author of Let Them Eat Dirt: Saving Your Child From An Oversanitized World tells The Current's Anna Maria Tremonti.

'The chance of getting an infection if you pick up a handful of dirt now is way less than it used to be say 100 years ago," says B. Brett Finlay, co-author of Let Them Eat Dirt: Saving Your Child From An Oversanitized World. (Alec Mills/flickr cc)
"If you look at ... Western society diseases — I'm including things like asthma, allergies, obesity, diabetes, inflammatory bowel disease, depression, stress, anxiety, autism — these things actually all have microbial links."

Finlay says scientific research is increasingly linking a lack of microbial diversity in children's guts to the rise in these Western diseases, though the causes and effects have yet to be fully understood. 

But he advises parents let their need for cleanliness drop a little — within the bounds of common sense.

"For the poor germophobe mothers out there," says Finlay. "I feel sorry for them because they're trying to do the very best."

"We've been told keeping your kids clean is the best thing you can do for them. But unfortunately the science is now telling us it's not the best thing to do."

Listen to the full conversation.

This segment was produced by The Current's Karin Marley.