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Pets, People And Place Help Pick The Microbes You Live With

National Institute of Allergy and Infectious Diseases (NIAID)
House dust, magnified.

Your home is filled with microbes. Fungi and bacteria cover your appliances, your door handles, and even your skin.

Yet researchers lack understanding as to which species live inside the home and how those species vary between homes. A new study shows that the region where you live shapes what kinds of fungi are in your house. The bacteria, however, are more affected by which pets you live with.

“We live with this broad diversity of different microorganisms in our homes,” says study author Noah Fierer, a researcher at CU Boulder’s Cooperative Institute for Research in Environmental Studies. “Some could be potential allergens, many could actually be beneficial, and most are probably innocuous.”

Fierer and a group of collaborators received more than 1000 samples from different people’s homes through a callout on Your Wild Life. The project is the latest in a series of citizen science experiments, where people send in swabs from their armpits, or in this case, the dust above their doorframes.

The genetic data the group collected showed evidence that more than more than 72,000 types of fungi and more than 125,000 types of bacteria were thriving in people’s homes.

The fungi the researchers identified vary mostly by region, that is, where you live determines your home’s fungal matter.

“Many of the fungi we find in the home come from outside the home, from the soils, from surrounding plants,” explains Fierer.

Bacteria, on the other hand, tend to vary based on who or what lives in the home. Cats bring one kind of bacteria and dogs bring another. To a lesser extent, the researchers can even venture a guess about whether a home’s tenants are male or female.

“Men and women harbor different bacteria on our bodies,” says Fierer. “We saw a subtle effect of whether there were women in the household on the types of bacteria found in the home.”

Clearly, no one needs microbes to determine their address or the sex of their roommates -- there are simpler ways to answer those questions.

The researchers say understanding the microbes inside a home can aid future investigations about air quality or allergens. Plus, the microbes living on and around us may have a big impact on our health and wellness. If we don’t know what those microbes are, we can’t figure out how they impact human health.

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