Learning to love our bugs

Each of us is a mobile ecosystem, teeming with trillions of living organisms. (Illustration by Giula Ghigini) 

By Jerry Grillo
Emory Medicine

They live on us and inside us, surround us like an invisible cloud, maintain and sustain us, ignore us, occasionally attack and kill us, and, ultimately, define us.

The human microbiome is made up of bacteria, fungi, viruses, and the like, and they cover every surface of our bodies.

"These microbiota are mostly in your gut, but also in your mouth, on your skin, in your lungs," says Emory biologist Nicole Gerardo. "They're playing critical roles in how you interact with the environment, how you process food, how you fight off pathogens, how you interact with drugs.

"Some of our remarkably fertile microbes are identical to those that live in other humans. But many are a distinct reflection of our individual experiences, shaped by who or what we've touched, where we've been, what we've breathed, and what we've consumed.

"Research interest in the human microbiome is exploding now," says Gerardo, who gave the introductory presentation at Emory's first microbiome symposium in November.

Spurred on by ambitious efforts like the National Institutes of Health's Human Microbiome Project, such research is demystifying the role of our myriad microbial passengers.

"It's like we're entering a new frontier of science, something that was basically ignored by medicine for a long time," says infectious disease researcher David Weiss, director of Emory's Antibiotic Resistance Center. "We're really at the beginning of studying all this, but I do think that in our lifetime, we'll be able to monitor each person's microbiome and intervene to improve their health. Looking at what type of bacteria we have and how resistant or sensitive they are to drugs will be an important part of health care. Most of the bugs we tote around are helpful, but they can also be ticking time bombs."

We may be able to someday diffuse the situation, replacing pathogenic microbes with a friendlier variety.

"There's great promise in manipulating the microbiome, in actually changing it," says geneticist Michael Zwick. "Actually, it's already happening."

Read the whole article in Emory Medicine.

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