Your own, personal microbial cloud

It’s floating around you all the time: a wafting cloud formed by billions of bacteria that fall off your body with every movement you make. At the university of Oregon, researchers have revealed that, not only can they detect and catalogue this personal microbial cloud, but each person’s cloud is unique.


It's floating around you all the time -- a wafting cloud formed by billions of bacteria that fall off your body with every movement you make.

At the University of Oregon, researchers have revealed that not only can they detect and catalog this personal microbial cloud, but each person's cloud is unique.

Here's the story.


When you're sitting in this room as a participant, you're hyper-aware of how you're behaving, you know -- 'Do I really need to scratch that itch?

Am I gonna run my hands through my hair?

Am I emitting particles just by doing that?'

Roxana Hickey is not normally a guinea pig in an experiment.

As a microbial ecologist, she's usually the not the

Humans actually spend up to 90% of their lives indoors, and so the fact that we're being constantly exposed to that environment is a good reason to study what kinds of things we're contributing and picking up from that environment.

Things floating in the air, like bacteria and viruses -- billions of organisms all around you all the time.

Being aware of them might make you a little self-conscious.

But for Roxana Hickey and the researchers at the Biology and the Built Environment Center, it's also a cause for celebration.

So, we study the fate and transport of microbes the way you would ecosystems and to also consider that they may not be necessarily harmful.

Or exotic, either.

We saw that humans were a very strong force in influencing what's going on in the indoor environment, and that pattern has emerged time and time again.

Just how big can our influence be on the indoor microbiome?

To find out, you need a very large and very controlled Petri dish of sorts.

Right now, we are sitting in the climate chamber at the Energy Studies in Buildings Laboratory.

So, this room is a unique research tool where we have the ability to control pretty much all of the environmental variables that exist in here, so temperature, relative humidity, airflow rate, and that gives us a great opportunity to be able to sample the particles that are surrounding an individual in a room.

You also need a good, clean -- or rather dirty -- set of samples.

The participants were asked not to bathe or shower the morning of the experiment.

They were also asked not to apply any products to their skin or wear perfumes or deodorants.

The participant walks in here, they sit down, and then we just collect the air while they're waiting.

And it doesn't take much to get our microbiome airborne.

On the human body, we have trillions of bacteria inhabiting every environment.

For example, our skin -- we have a skin microbiome that is distinct from our gut microbiome.

We have microbes in the urogenital tract.

We have them on our feet, our hands.

So if you touch a human being or you touch a surface, then you can transfer your human microbiome to that surface.

And then we are also directly shedding microbes from our bodies.

So when your skin sloughs, for example, that's one mechanism that then gets suspended on our chairs or on our tabletops, on the floor.

And then just by moving about, those end up getting re-suspended, and we're exposed to them that way.

And so by using this controlled chamber, the researchers captured airborne microbes on Petri dishes and sterile filters.

So, once we get them back to the lab, we use a buffer to wash the cells off into solution and then we use that solution to extract DNA, and we use that information and variations in that code to determine what types of bacteria and fungi we have in that sample.

Revealing a very human picture.

Even just the act of sitting there gives off enough microbes for us to be able to detect a person in a room.

So we really are surrounded by a microbial cloud.

What exactly's in that cloud?

The main types of bacteria that are found in the cloud are gonna be skin and oral-associated microbes, and so these would be things like Staphylococcus, Propionibacterium, for instance.

But that's not all they found.

We also have, time and time again, seen a significant number of gut-associated microbes in the indoor environment.

But having so-called 'fecal bacteria' wafting around you should neither surprise or alarm you.

Most of the microbes that are found -- even in our gut, in our urogenital tract -- those are healthy microbes.

We need those to be healthy, and so the fact that they're everywhere is not alarming.

It's just part of the natural dynamics of microbial communities on our bodies.

What surprising is how unique our microbial impact can be.

We can compare the particles that are in the room when different individuals are present at different times, and their individual microbial clouds actually are distinct from one another.

Now is a small sample size, and we are now asking questions such as, 'Can you identify an individual out of a crowd?'

We're trying to understand how far these particles actually move if a person is just sitting in a chair.

Are the microbial clouds getting mixed together?

How long do they last?

What activities affect them?

Can they change your own microbiome?

If sitting in a room by yourself pondering these questions leaves you feeling a little self-conscious, you're not alone.

I am sitting in an ecosystem right now.

It's where I'm gonna spend 90% of my life, and I don't know anything about this ecosystem.