Humans Have Personalized Microbial Clouds

Yes, our microbial clouds might even serve as airborne fingerprints.

It turns out this personalised microbial cloud is unique to each of us. Previous research found that we put our microbial footprint into the room we’ve just entered relatively quickly, with your house having different mircobiomes than your office or the hotel room you spent a vacation in.

Like the Peanuts character, Pigpen, each of us emits a cloud of bacteria that is uniquely our own, according to a new study. Each participant was given an identical new and clean outfit to reduce the number of particles coming from clothing. The participants communicated with the researchers using a laptop (they were given the laptop in order to keep themselves entertained). The air was then compared to a adjacent, unoccupied test space next to them. The air was sequenced in a sanitized experimental chamber. Past research has shown that it’s possible to lift someone’s microbiome from surfaces they’ve touched, sequencing the DNA of bacteria left on kitchen counters, floors, and bathrooms for clues about the person who left them there.

Subsequent experiments enabled the researchers to determine who had been in a room simply by sampling its “odour”.

This result motivated a second, more precise experiment. For this experiment, 8 new participants were ask to sit in the chamber for two 90-minute sessions.

It may sound gross, but it’s all something that we live with each and every day.

Author James Meadow said his team was surprised to discover that the microbial cloud can be used to identify the person.

While these common human-associated microbes were detected in the air around all people in the study, the report found that the different combinations of those bacteria were the key to distinguishing individual people. “There are just really subtle differences”. Some people, for example, gave off different amounts of bacteria to the air due to such personal habits as how much they scratched and how much they fidgeted.

The research sheds light on the extent to which we release our human microbiome to our surrounding environment, and might help understand the mechanisms involved in the spread of infectious diseases in buildings.

Within 1.5 to 4 hours, the air in each occupied chamber was filled with a rich array of bacteria.

This means criminals might one day have to worry about leaving behind bacterial evidence at a crime scene, as well as just fingerprints, which can even be used to track their movements. “But hopefully as technology progresses and we are able to reduce the lowest detection limits, we can maybe push the envelope a little bit and start to capture a personalize signature in a more realistic environment”.