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Public Radio's Environmental News Magazine (follow us on Google News)

Belly Button Biomes

Air Date: Week of

Researchers explore one of the last biological frontiers: the microbial jungle that is our belly button. Jiri Hulcr, a postdoc in biology at North Carolina State University, leads the quest.


GELLERMAN: Don't look now, but in all likelihood, lurking on your body are life forms that no scientist has ever studied. That is, until Jiri Hulcr began probing the microbial jungle we call our belly button. Hulcr is a postdoc in biology and chief navel gazer at the Belly Button Biodiversity Project at North Carolina State University. Jiri Hulcr - hello!

HULCR: Hello!

GELLERMAN: Belly Button Biodiversity Project? What do you find in the belly button growing that you don’t find in other parts of the body?

HULCR: It’s actually a fairly unique place on the body, not only because that’s where we all started - that obviously was our connection to our mothers in our past - but the belly button is one of the few places that no one ever notices, really. And, subsequently, no one ever really washes them. We asked people in completely anonymous questionnaires how often they washed their belly buttons with soap and it turns out that not many people do.

A lot of people lie about it, but not many people do. And so that’s great for the bacteria. We are trying to find out what the native, real, natural, undisturbed biota is on the human body. And the rest of the body either is heavily scrubbed daily in most people, such as the regular surface of skin, or other crevices and nooks and crannies, such as the armpit, or the nose, or the mouth and so on - they have special adaptations, they have special secretions, and they have other features that make the bacteria that live on them different than the rest of the skin. But the belly button doesn’t secrete anything - it’s just a safe haven for the bacteria and so it’s a great place to go sample them.

GELLERMAN: (Laughs). Well how do you sample a belly button?

A sample of the life that thrives inside our belly buttons. (North Carolina State University and the NC Museum of Natural Sciences.)

HULCR: So we don’t actually do that. We don’t actually touch anybody - fear not. We provide everybody who is interested a Q-Tip and a vial, and each person samples their own navel. We plate them on a nutritious media, on which bacteria grow happily, and grow them. And this is what - these are the pictures - the agar plates, they’re called, that you see online in our database.

GELLERMAN: I was looking at these little dishes of bacteria. It looks like Google Earth.

HULCR: Sometimes it looks more like Google Stars, doesn’t it? They are really incredibly variable and form various constellations. We have so many people telling us that they see shapes there and that they see constellations or faces and so on.

GELLERMAN: Oh, I most definitely see a shape. Yours is one of those that was sampled, and yours looks like little islands.

HULCR: Oh yeah! And each of those islands is a little colony of millions and millions of bacteria. What you see on the plate are not actually individual large bacteria - which this was a surprise to us that a number of people thought that the little dots, the colorful blobs that they see, are big bacteria. That’s actually not true. They are composed of millions or trillions of individual, single-cell, minute bacteria that just happened to originate from a single one.

GELLERMAN: Boy, it’s a microbial jungle out there! Or down there!

HULCR: Indeed! We are really interested in the diversity. We are not only growing those bacteria to show to people - that’s more the fun part. We are actually taking most of the sample and isolating DNA, and we are reading this DNA to identify all the bacteria in the sample.

GELLERMAN: So what are you finding when you take these samples?

HULCR: We are finding big differences between people, for example. You can see that, even when you just take a look at the plate, everyone is slightly different in terms of abundance. That’s expectable - that’s also because…

GELLERMAN: Oh, for sure! I mean, I’m looking at Meg Lowman’s sample that’s online and hers is loaded - it looks like Australia and part of Southeast Asia there!

HULCR: (Laughs). Yes, no, that’s definitely the truth. That’s, of course, partly reflecting on how people are serious about their sampling. If they really poke in deep, then they’ll get a good sample. If they are a little hesitant, then we get only a few colonies, but the diversity - the numbers are one thing, but the numbers of kinds or species, if you will, are also…that’s also surprising.

GELLERMAN: You know, after you get past the, kind of, the laugh factor and the yuck factor - this is serious stuff. I mean, you were finding Pseudomonas, right?

HULCR: Absolutely. We are finding Staphylococcus, we are finding yeasts, we are finding Aspergillus filamentous fungus. We are finding lots of organisms that are normally, in most people’s minds, associated with a disease or with something unhealthy or dirty. One of the main goals, really, one of the long-term overarching goals of this project is to change people’s perception of their own symbiotic microflora. Only if something goes wrong, only if one member predominates, or if we scrub ourselves too much - for example, if we do something that’s akin to clear-cutting in the forest, then you get all the weeds growing really fast.

But if the forest is old and dominated by diversity of slow-growing and metabolically versatile trees, or in our case bacteria, then you generally tend to get balance. And of course there are weeds growing all over the place, but they’re never dominant. And it’s only when we do something wrong or when there is something wrong with our immune system or if there is something wrong with our bacterial ecosystem that we see some of those go wild and grow over everybody else.

GELLERMAN: I noticed you have a lot of fun online, on your website, and you have a segment that says, “Lady GaGa lives the wild life - she also hosts it.” (Laughs).

HULCR: That’s exactly right. In fact, both Lady Gaga and you, and me and everybody else - we have more bacterial cells in our body than human cells. And so we are really, essentially, walking human covers for microbial biota.

GELLERMAN: Jiri Hulcr is a postdoc probing innie and outie space at the Belly Button Biodiversity Project at North Carolina State University.



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