Oregon – Scientists recently found that everyone emits a cloud of bacteria that is unique. This “personal microbial cloud” is so distinctive that researchers can even identify someone just by studying the air in that individual’s room. The findings were published on September 22 in the journal PeerJ.

It has been long known that humans host a countless of (mostly helpful) microbes, in the gastrointestinal tract and on the skin. This colony of organisms is what scientists have called the “microbiome”. The study found that people also emit some of their microbiome in a some kind of haze around themselves, and it is as unique as a fingerprint.

Credit: Monabasolo

Further analysis of these “clouds of bacteria” can be useful for doctors tracking down disease outbreaks and even for police authorities who are searching for criminals.

Previous researches showed that three main sources contribute to the airborne cloud of bacteria that surrounds everyone. This are: dust, emissions from clothing and emissions from the person, according to the experts.

The Experiments

For the study, scientists asked participants to sit alone in a sanitized chamber filled with filtered air. To equal the circumstances, they gave each volunteer an identical new and clean outfit. Each participant then sat on a plastic rolling chair, which was previously disinfected, and were also given a laptop so they could communicate with the team of researchers outside.

The particles discharged from the participants were filtered, collected and genetically sequenced. Scientists used theses sequences to later identify the bacteria.

In one of the experiments, the team of experts compared the air in the chamber with a neighbor and unoccupied chamber. For this experiment, three volunteers sat in the chamber for 4 hours and then for a second session of 2 hours.

After 2 hours, researchers were able to tell if the person was inside the chamber just by looking at the bacteria for the air samples. However, the team noticed that they could actually identify each participant because of the combination of bacteria that surrounded them.

With this in mind, the experts elaborated another experiment to determine how accurately they could identify individuals by analyzing their unique cloud of bacteria. For this experiment, 8 new participants were ask to sit in the chamber for two 90-minute sessions.

After this, researchers discovered that the main types of bacterias found in the participants’ “clouds” were: Streptococcus, which is commonly found in the mouth; Propionibacterium and Corynebacterium, which are commonly found on the skin. For female volunteers, scientists noted the presence of common vaginal bacteria.

“We expected that we would be able to detect the human microbiome in the air around a person, but we were surprised to find that we could identify most of the occupants just by sampling their microbial cloud,” said the study author James Meadow, of the University of Oregon, in a news release from the journal PeerJ.

Source: PeerJ