Sampling Your Home’s Microbes

Your (Bacterial) Home: The Next Ecological Frontier

The human household is one of the few ecosystems on Earth becoming increasingly more common. Each day, more foundations are laid, more sidewalks are poured and more lawns are mowed.

The species in and around our households are interesting intrinsically. They are the ones we interact with most often, and they are the species among which evolution is likely proceeding most rapidly, both because their biome is expanding and because they are very often small and reproduce rapidly. These species living on and beside us are also interesting for another very important reason: their presence and absence may directly influence our health and wellbeing.

Yet curiously scientists have dedicated relatively little attention to understanding the ecology and evolution of the species that live alongside us, be they bacteria, fungi, or insects…until now.

Enter the Wild Life of Our Homes Project.

With simple sampling devices, statistical wherewithal, and the ability to detect invisible species using genetic methods, we now have the tools and techniques necessary for domestic exploration. But we’re missing one very important member of our team: YOU. We need you, the citizen field biologist to go boldly where few have gone before, into the life-filled ecosystem of your house.

With your help, we’ll start by exploring the microbial life of our homes. Microbes are abundant and ubiquitous on our bodies, in the environment, and in our homes, yet we know so little about their diversity in the most everyday places. We aim to change that by building an atlas of house-associated microbial diversity. We’ll use information you provide about the features of your house and lifestyle to test a handful of hypotheses that might explain something about the microbial communities we observe in your homes:

Hypothesis 1: Your home’s physical characteristics influence the microbial communities found inside it.

We think some of the physical and design attributes of your house might determine the microbial species that live there. Consequently, we’ll ask you a few questions about the architecture, building materials, carpeting, ventilation, and heating and cooling system of your home – think of these questions as characterizing the ecological conditions inside your home. If patterns emerge linking home characteristics to specific types of microbes, our research could ultimately suggest useful ways to re-design our homes.

Hypothesis 2: The macro-species with whom you share your home influence the microbial species found within it.

It’s likely that your home’s occupants (particularly those you see and interact with on a daily basis) might play a role in structuring the microbial communities we find living in there. Not only do we hypothesize that the number of humans occupying your home matter to microbes, but we suspect their age and sex could too. We think the non-human species you keep in your home may also wield some influence on the type of microbes we find there – so we’ll ask you questions about your pets (type and number) and even the number of house plants you maintain.

Hypothesis 3: Geography, climate and landscape features influence the microbial composition inside and outside of houses.

While home design and occupancy might have a strong influence on the microbes in your house, the other non-exclusive possibility is that where you live also impacts the microbes living on or in your house. Realistically, it is very unlikely that the species in a house in Alaska and one in Florida are the same, or that Grandpa’s Iowa farmstead shares exactly the same species with Cousin Beverly’s Park Avenue penthouse. But how different are they really and what accounts for those differences?

To characterize the outside environment of your house, we can do everything from space (and our desktops). With your address in hand, we’ll use a range of large, publicly available data sources to describe the outside attributes of your home – climatic conditions, amount of paved surface (a proxy for how rural or urban your home location is), density of people living in your neighborhood, and vegetation – each factor we think has the potential to influence the creatures with which you share your home.

Hypothesis 4: The microbes you live with influence your health and wellbeing.

A number of adverse health symptoms or diseases (itchy eyes, headaches, asthma, allergies, and auto-immune disorders, to name a few) may be linked to changes in the microbial species with which we live. Perhaps, as a consequence of “modern” living we’ve lost some beneficially protective species or improved the conditions for the survival of pathogens. After all, we now spend less time getting “dirty” outside, and many of us live in homes with central air, sealed windows and surfaces scrubbed clean, at every opportunity, with antimicrobial wipes.

The final goal of our study is to understand if the variation in microbes in our homes is associated with variation in health and wellbeing. To that end, we’ll ask you about your cleaning practices as well as some general questions about the health of your household. We’ll then try to model factors associated with microbial composition or household characteristics that best predict the presence of these symptoms or diseases.