Are you one of the many people who ask family and guests to remove their shoes before walking through your home? If so, you may have the right idea. In this article from The Wall Street Journal, doctors explain the science of footwear germ transmission.

Is It Worth Enforcing a Shoe-Free Home?

In cities and suburbs alike, more people are adopting a no-shoes-at-home policy. It is more hygienic, practitioners say, and keeps out outdoor germs. Is a shoe-free policy really better for our health? Heidi Mitchell reports. Photo: Getty.

In cities and suburbs alike, more people are adopting a no-shoes-at-home policy. It is more hygienic, practitioners say, and keeps out outdoor germs. Is the argument grounded in science? One expert, Stephen S. Morse, professor of epidemiology at the Mailman School of Public Health at Columbia University, explains what lies deep in the sole, and when not to ask guests to go barefoot.

What’s Tracked In

Mud and dirt collect in the grooves of shoe soles, especially after rain or snow. Even if a person is walking through seemingly clean office buildings, shoes pick up lots of unexpected grime. Bacteria and viruses such as E. coli and those that cause influenza may also attach themselves to shoes. Near farmland or any exposed soil, more harmful pathogens may lurk. That said, “they’d have to make their way into a human through a lesion on the skin, and that’s a pretty far-fetched scenario,” Dr. Morse says.

Carpets and wet surfaces might harbor fungi such as those that cause athlete’s foot and the virus that leads to Plantar warts. The risk of catching anything more severe is low, however, whether a no-shoe policy is strictly enforced or sometimes lax.

Who Should Consider It

Homes with crawling babies might benefit from being shoe free because little ones are more likely to put items found on the ground into their mouths or leave unpleasant things behind for adults to step on. Dr. Morse also offers a practical reason: Wood floors and other surfaces can look cleaner without shoe traffic. In his home, Dr. Morse tends to remove his shoes at the door “for the sake of keeping my marriage intact,” he says.

The Case for Slippers

Dr. Morse points out more immediate problems with going shoeless: injuries that might occur while walking around in bare or stocking feet. “You could step on a nail,”he says. “But mostly, the concerns are aesthetic.”

Since he isn’t comfortable going public with bare feet, he’ll wear socks or slippers. “A thoughtful host might provide disposable slippers like the ones they give away in business and first class on airlines,” he says, though he’s never actually experienced this form of hospitality.

The Hygiene Hypothesis

Because forcing repairmen or dinner guests to remove their boots or shoes each time they enter the home is a hassle, Dr. Morse believes that insisting on a shoe-free policy isn’t worth it. Besides, he says, a little dirt can be a good thing: “The Hygiene Hypothesis says that one of the reasons why we see asthma and allergies is because the immune system isn’t being kept busy with fighting off the bad guys,” he says. “There is evidence for both sides, and we epidemiologists debate this every week.” As long as guests wipe their feet on the doormat, shoes are fine, he says. “It might save your floors a lot of cleaning, but other than that, we have no reason to believe that shoes in the home are a real hazard.”