Humans are colonized by the same types of microbe as the people and the pets they live with.

Rob Knight at the University of Colorado Boulder and his team used DNA sequencing to analyse the microbes colonizing the skin, guts and mouths of 159 people and 36 dogs, living in 60 households.

Humans tended to have similar microbial communities — particularly on the skin — to their spouses and children. Adult dog-owners also had more skin microbes in common with their dogs than with other dogs. However, microbes in the mouths and guts of canines differed from those of their owners. Shared skin microbiota might help to explain why dog ownership is associated with reduced allergy rates in children, the researchers say.

eLIFE 2, e00458 (2013)