Do you remember Pig-Pen, the Peanuts comic character who's
always surrounded by a cloud of his own filth? Well, it turns
out that we're actually all a little like him. Scientists have
discovered that not only does everyone emit an invisible
"microbial cloud," but that individuals can be recognized by the
bacteria that make up their particular cloud.
A team from the University of Oregon placed 11 test subjects in
a sanitized chamber, one at a time, then analyzed the airborne
microbes that each person left behind. It was found that within
four hours, it was possible to identify most of the subjects by
comparing their residual "microbial cloud signature" with a
fresh one obtained directly from them.
Although all the people emitted mostly the same types of
bacteria – such as Streptococcus from the mouth, plus
Propionibacterium and Corynebacterium from the
skin – the relative proportions of the different varieties were
distinct to each person.
It is hoped that the team's findings could lead to better
understandings of infectious diseases, and even be used by
forensic investigators to establish if a given person has
visited a specific location. That said, it still remains to be
seen if the technique can be used in public spaces, where
multiple microbial clouds are present simultaneously.
A paper on the research was recently published in the journal
PeerJ.