Not under the skin, but on it: Living together brings couples` microbiomes together
(PHYSorg.com Biology)

Couples who live together share many things: Bedrooms, bathrooms, food, and even bacteria. After analyzing skin microbiomes from cohabitating couples, microbial ecologists at the University of Waterloo, in Canada, found that people who live together significantly influence the microbial communities on each other`s skin.