WATERLOO, Ontario — Sharing a toothbrush with your partner may sound gross, but it may not be all that unpleasant should you consider you’re already sharing bacteria — all over your body, and especially on your feet.
A recent study of microbiome — the communities of bacteria, viruses and other microscopic critters that live on our skin and in our gut — found that these microbial communities can be accurate predictors of who we live with.
Researchers from the University of Waterloo focused their study on the microbial communities living on the skin. They analyzed the biomes from 330 skin swabs from 17 different areas of participants’ bodies, including one’s armpits, nostrils, eyelids, and feet. The similarities were strong enough that an algorithm could almost always correctly match couples based on their biomes alone.
There were differences, however, in how much microbiome was linked to another person based on the location of each sample. For example, couples’ feet seemed to have the highest amount of matching microbes in each other.
“Your feet not only look like yourself, they look a lot like your partner as well,” explains Ashley Ross, the study’s first author, in a news release.
Previous research proved that skin microbial communities are different in people from region to region, but Ross and her co-authors wanted to learn what other factors shaped each biome.
“In hindsight, it makes sense,” explains co-author Josh Neufeld, a professor of biology. “You shower and walk on the same floor barefoot, and this process likely serves as an effective form of microbial exchange with your partner, and also with your home itself.”
The algorithm the researchers developed to help them match biome data was correct in predicting couples 86% of the time. Neufeld says the project is part of a research effort to learn how microbial biomes change with their host.
The full study was published in, mSystems, an open-access journal of the American Society for Microbiology.