Microbe mix varies by kind of home

WASHINGTON — From the jungle to the city, humans’ microbial houseguests vary.

The community of bacteria teeming in people’s homes changes as dwellings get more urban, researchers report February 12 in Science Advances. In the city, more household bacteria come from humans, study coauthor Maria Dominguez-Bello said at a news conference February 11 at the annual meeting of the American Association for the Advancement of Science. Some of these bacteria could cause diseases. Urban living may also keep out environmental microbes, which help people’s immune systems develop.

Dominguez-Bello’s team surveyed the microbes living in houses (and on people) from four different locations: in Peru, a jungle village, a rural village and an urban town; and in Brazil, a modern city.

Loads of bacteria lived in each location, but the types of bacteria varied with the houses’ floor plans.

The open huts in the jungle, for example, hosted more bacteria from the outdoors than the multiroom homes of the town and city. In these more urban homes, interior walls and a lack of ventilation may trap bacteria from humans, said Dominguez-Bello, a microbiologist at New York University Langone Medical Center.

Researchers could even use wall bacteria to distinguish between rooms. “We can swab a space in a house and tell you that this is a kitchen or this is a bathroom, or this is a living room,” she said. “That’s amazing.”