There are hundreds of millions of disgusting reasons you should ask your Thanksgiving guests to take off their shoes this holiday. We're talking about the bacteria on the bottom of shoes.
Joshua Shrout is a microbiologist and an associate professor at Notre Dame. His lab looks at what bacteria does on various surfaces.
Shrout says he asks people to take off their shoes at his house -- because he knows what’s on the bottom of them.
“So, on peoples' shoes is everything that we are around all the time. So you can imagine on shoes there’s going to be a lot of bacteria from soil or other environmental things,” says Shrout. "Certainly we are tracking our shoes around, so what’s on our shoes from one building is going to end up where we go next and so on.”
He says there are hundreds of millions of bacteria that people carry around on the bottom of their shoes. Most of that bacteria is harmless. However, our shoes go where we go, which means outside, in the bathroom, and at work. The bottom of your shoes pick up and carry some of what they collect in those places. That could include chemicals, soil and fecal matter.
“Most of these bacteria are innocuous or absolutely needed to keep us healthy, but when one of those bad pathogens gets in -- they are not usually making us sick, because we have a healthy immune system and ways to keep them out,” says Shrout. "But when they do, that’s when we get sick."
Shrout says cold temperatures don’t kill bacteria. Rather, he says it leaves most bacteria in a state of suspended animation.
He also says wiping shoes on the welcome mat won’t get all the bacteria off.
Shrout says your best line of defense is something you probably already do.
“Wash your hands,” says Shrout, “because when you are worried about the fate of where these bacteria are and how they might affect you, really your number one protection is just to make sure you wash your hands.”