Abstract
Human-associated microbial communities vary across
individuals: possible contributing factors include (genetic) relatedness, diet,
and age. However, our surroundings, including individuals with whom we
interact, also likely shape our microbial communities. To quantify this
microbial exchange, we surveyed fecal, oral, and skin microbiota from 60
families (spousal units with children, dogs, both, or neither). Household
members, particularly couples, shared more of their microbiota than individuals
from different households, with stronger effects of co-habitation on skin than oral
or fecal microbiota. Dog ownership significantly increased the shared skin
microbiota in cohabiting adults, and dog-owning adults shared more ‘skin’
microbiota with their own dogs than with other dogs. Although the degree to
which these shared microbes have a true niche on the human body, vs transient
detection after direct contact, is unknown, these results suggest that direct
and frequent contact with our cohabitants may significantly shape the
composition of our microbial communities.