This is what it that biofilm in your refrigerator drawer looks like magnified by an electron microscope. Photo Credit: Noah Fierer
This is what it that biofilm in your refrigerator drawer looks like magnified by an electron microscope. Photo Credit: Noah Fierer

… and on your countertops, and your sofa, and on the TV remote, and on your keyboard. And that’s a good thing, apparently.

By Stephanie Soucheray

According to new research coming out of NC State University, your pillowcase and your television set may have the same types of microbes, bacteria and, yes, even wildlife on them.

If your response is one big collective “yuck,” the researchers at NC State’s Your Wildlife program have some news for you.

This is what it that biofilm in your refrigerator drawer looks like magnified by an electron microscope. Photo Credit: Noah Fierer
This is what it that biofilm in your refrigerator drawer looks like magnified by an electron microscope. Photo Credit: Noah Fierer

“Your house is covered in life, and no one, or no house, gets to avoid it,” said Rob Dunn, scientist and author of books such as The Wild Life of Our Bodies . Dunn was the lead author of a paper, Home Life: Factors Structuring the Bacterial Diversity Found within and between Homes , which was published last week in the journal PLoS One.

Dunn and other scientists looked at 40 houses in the Raleigh-Durham area to draw a microbial schema, if you will, of the average home. All homes had thousands of types of bacteria, many of them belonging to unidentified species.

And each type of bacteria showed clues of its origins in the home. Dunn said areas of the home where food is prepared – think kitchen counters and refrigerator handles – have plant-based bacteria, door and windowsills have soil-based bacteria, while bathroom surfaces have oral and fecal bacterial. Even your container of antibacterial wipes is loaded with organisms.

It’s not a pretty picture, but Dunn said the message of his work is counterintuitive.

“It’s the opposite of what you think,” said Dunn. “Having fewer species of bacteria in your home is bad, and more biodiversity is better.”

Dunn said his work showed that houses with dogs, in particular, had more than half again the types of bacteria than houses without canines.

Household locations sampled by NCSU researchers. Credit: Neil Mccoy
Household locations sampled by NCSU researchers. Photo credit: Neil Mccoy

“That’s a remarkable number,” said Dunn. “I was expecting maybe a 2 percent increase of variation, but this is a dramatic difference.”

While Dunn said talking about his work makes him think about getting a dog – and of course stirs up some ire among cat folks – he offered a strong hypothesis as to why four-legged animals that bring more bacteria in the home are beneficial.

“The more we recreate a less sterile environment, the better,” said Dunn. “It creates a sense of biodiversity that brings the outside in.”

Dunn explained that scientists are moving to understanding a model of immunity and bacteria that says more of the latter is better for the former.

“We have a suite of immune problems with a failure to get immune in the modern world,” he said. “Even the modest contribution of dogs is enough to restore our health a bit.”

Now Dunn and his colleagues are looking at 1,300 houses, which will further help map common bacteria trends in the home. He’ll look at how pets, climates and other factors influence bacteria and what that can mean to the health of inhabitants.

Electron microscope view of the dust collected from a door frame. Photo credit: Noah Fierer
Electron microscope view of the dust collected from a door frame. Photo credit: Noah Fierer Credit: Noah Fierer, University of Colorado

His research falls in line with other studies  that have shown that households with pets can lower the risk of asthma for children and that pregnant pet owners pass on stronger immune systems to their offspring.

“With the whole Your Wild Life project, we’re trying to get people, and even microbiologists, to look at their homes differently,” said Dunn.

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Rose Hoban is the founder and editor of NC Health News, as well as being the state government reporter.

Hoban has been a registered nurse since 1992, but transitioned to journalism after earning degrees in public health policy and journalism. She's reported on science, health, policy and research in NC since 2005. Contact: editor at northcarolinahealthnews.org