© iStock
A team of would-be ghostbusters have developed a device to measure the 'exposome' - an invisible and somewhat spooky cloud that orbits every human. It is populated by bacteria and viruses, and may change how we view medicine.

"For years we've been sequencing people's genomes, testing their blood and urine, and analyzing the microbes in their guts to understand how these things impact human health," geneticist and lead author of the researchMichael Snyder from Stanford University told Wired. "But all of those things have to do with what's inside your body. The one big thing we're missing is: What are you exposed to?"

Snyder and his team developed a device, roughly the size of an old cell phone or a pack of cards, which sucked up the air around the 15 participants for periods of between one week and one month. Unfortunately, it wasn't just the aroma from their aftershave and perfume that the device inhaled.

The monitors captured bacteria, viruses, fungi and pollen, as well as several insecticides and carcinogens, as the participants went about their daily lives in roughly 50 locations in the San Francisco Bay Area. The researchers then meticulously sequenced every substance the devices inhaled, producing a first-of-its-kind database made up of roughly 70 billion readouts covering approximately 40,000 unique entries.

"Scientists had assembled separate bacteria, viral or fungi databases, but to fully decode our environmental exposures, we built a pan-domain database to cover more than 40,000 species,"says one of the team, Chao Jiang. The researchers soon began to realize that even those participants who occupied the same areas had their own unique 'invisible friends' in their exposomes.

"The bottom line is that we all have our own microbiome cloud that we're schlepping around and spewing out," Snyder said, admitting that although the current study is limited in scope (only three individuals wore the devices for an extended period of time), it could mark the beginning of a new area of medical research.

For instance, Snyder's allergies, which he believed were caused by pine pollen, were actually shown to have a higher correlation to eucalyptus through analysis of his exposome data. Snyder suggests combining immune response data (through blood or urine sampling via traditional medical practice) with that collected through his exposome device in order to create a more complete picture of human health.

At present, the device costs $2,700 to produce and is apparently quite easy to misplace; Snyder himself admits to having lost four. However, the team are optimistic that their research holds promise for developing a more comprehensive approach to medical treatment in future.