When a couple decides that it is time to move in together, it is clear that they accept that, from that moment on, they will have to share many things, such as the bathroom, the kitchen, or the bed. However, when we move to live with our loved one, everything changes, including the microbes on our skin. This has been determined by a team of researchers from the University of Waterloo in Ontario (Canada), which has concluded that when we live as a couple there is a great exchange of microbes, which causes our microbial profile to change.
In the study, published in MSystems, an open access journal of the American Society for Microbiology, experts found that each person in the relationship significantly influenced the microbial communities on their partner’s skin. Using microbial data, various computer algorithms were able to match the lovers with 86% accuracy. Of all these data, the part of the body in which the most exchange of skin bacteria took place was … the feet.
Why precisely the feet?
Causation was not analyzed, but scientists believe it could be due to couples walking barefoot on the same surfaces in the house, making it easier to transfer bacteria between themselves and their immediate surroundings.
“You shower and walk barefoot on the same floor, and this process probably serves as an effective form of microbial exchange with your partner, and also with your own home,” says Josh Neufeld, leader of the work.
The experts analyzed a total of 340 skin samples from 10 heterosexual couples who currently live in the same house, to observe the influence that cohabitation had on the skin of an intimate partner. Samples were collected from 17 sites throughout the body, including the navel, armpits, and nostrils.
Although it is true that people have several bacterial skin communities depending on the area, this finding shows that factors such as cohabitation can really give a new shape to. microbiome.
However, not all areas of the skin share the same microbiome in the couple. For example, the researchers found that the microbe communities collected on the thighs were more similar between people of the same sex than those who lived together. This could be related to the fact that bacteria on the inside of female thighs are influenced by the vaginal microbiome.
Microbiomes are unique but, at the same time, they are easily influenced. Diet, the environment, and even a simple chance encounter, can affect the microbiome, so it is not surprising to share a bed with someone and have their bacteria on the skin, since this coexistence affects the composition of the microbial profile itself.
Most bacteria on the skin are harmless or even beneficial, preventing pathogenic microbes – bacteria that can cause infection – from inhabiting that area.
The study results are consistent with previous research that has concluded that married couples also influence each other’s immunology. Immune systems tend to reflect lifestyle habits, such as diet and exercise, that tend to coincide with couples living together. This is the reason why we usually get sick at the same time or catch a cold, for example, since we are in the same environment breathing pollutants, mold and dust together.
Citation: Ross AA, Doxey AC, and Neufeld JD. The Skin Microbiome of Cohabiting Couples. MSystems . 2017.
