When Emily Taylor was desperately sick with a bacterial infection that ravaged her gut, she found an unlikely cure: her father's stool. After being treated for Lyme disease and chronic fatigue with a course of antibiotics in 2009, Taylor had developed the potentially deadly Clostridium difficile (C. diff) infection. "In one month, I lost 40 pounds. I couldn't keep food down," says Taylor (not her real name), a Kingston-based artist. "I was extremely fatigued and in bed, and at the end of it I couldn't take care of my young daughter. I was going to have to be hospitalized pretty soon." Since all her doctor could offer were more antibiotics, which only made her worse, Taylor took matters—including waste matter—into her own hands. It was on the Internet that she came across the idea of a fecal transplant. A simplified version of the process involves taking fresh, donated stool from a healthy person (in Taylor's case, her father), whirling it up with water in a blender, and inserting it via enema where the sun doesn't shine. Almost immediately, the "good" bacteria from the donated stool help to repopulate the sick gut, keeping the pathogenic bacteria in line and restoring the system to health. "It's pretty gross because it smells horrible, and, you know, it's poop," says Taylor. "But it was so worth it. It made a huge difference right away—it was incredible." After just a three-day course of this unusual, not-for-the-faint-of-stomach solution, she was back to living a more normal life. And the blender? "I threw it away," says Taylor.
A Friendly Invasion
Radical as it sounds, fecal transplant is just one example of a game-changing way of thinking about health and disease, and it's taking the scientific and medical worlds by storm. A storm of bugs, that is. Researchers are looking to the human microbiome—the vast colonies of bacteria that live in and on just about every part of our bodies—for the secrets to understanding and treating a range of diseases, from rheumatoid arthritis and inflammatory bowel disease to diabetes, autism, and cancer. "This idea that we were raised with, that the only good bug is a dead bug, may sound intuitive but it's not true," says Lita Proctor, coordinator of the Human Microbiome Project at the National Institutes of Health in Bethesda, Maryland. "The vast majority of microbes that we come in contact with on a daily and lifetime basis are actually either benign or in many cases beneficial. In fact, we couldn't live without the microbes. This is a super-new idea, and it's about thinking of the human body as a whole ecosystem."
In this ecosystem, it turns out that there's more "them" than "us." If you added up all the human cells and all the microbial cells in your body, the microbial cells would outnumber the human cells by 10 to 1. In other words, you're not alone—although it takes a few years to develop the mature microbial communities that populate the body. An unborn fetus does not host a single microbe, but during delivery, vast bacterial communities from the mother's birth canal colonize and inoculate the infant. From then on, life is a snowball effect of microbes gathered from food, people, clothing, pets, air—in short, everything.
"By the time a child is approximately three years old, it has trillions of microbial cells inside its mouth, its skin, its nose, its GI [gastrointestinal] tract—every surface has its own particular microbial community," says Proctor. "They're unique to each body site and they do many things, including acting as a major trigger for the child's immune system. They can create antimicrobials that fight off pathogens. In the gut they play other important roles; they help digest our food, and they also make anti-inflammatories." Most of them—about three pounds' worth—live in the gut: About 50 percent of the dry mass of human stool consists of microbial cells. Something so omnipresent in our bodies is bound to impact our health, and the microbiome may well be the elephant in the room of the scientific and medical worlds. "We're starting to recognize that when we think about disease we have to include now this major contributing factor, which hasn't necessarily been a normal part of our thinking," says Proctor. "Not only do we need to think about genetics, but we need to think about the contribution of these microbes to human health."