Studying our natural internal bacteria could help doctors cure diseases that affect millions
The Whole Body Hospitals are already swabbing people's noses to screen for drug-resistant bacteria. "You get results in less than an hour," Serge says. Howard Schatz
When Jake Harvey visits the clinical center at the National Institutes of Health in Bethesda, Maryland, he is usually dirty, itchy and wheezing?not the happiest state of affairs for a 14-year-old boy. But his doctors require that for 24 hours prior to each visit, he refrain from bathing, or using the inhaler that soothes his asthma, or applying the ointment that softens his eczema. In order to study his illness, they need him to be in as close to his natural state as possible.
Jake?s discomfort could lead to better treatments for the millions who have eczema?a disorder marked by dry red rashes in the creases of elbows, behind knees and on the back of necks?as well as an array of other allergic reactions. By understanding eczema in a new way, as the product of a delicate interaction between the immune system and the legion of bacteria that live on the skin, one group of scientists hopes to better understand what triggers it and why the number of diagnosed eczema cases in developed countries has dramatically increased over the past few decades.
These researchers, led by Heidi Kong, a dermatologist at the Center for Cancer Research at the National Cancer Institute and Julie Segre, a geneticist at the NIH, are just one part of the five-year, $173-million Human Microbiome Project (HMP), an effort to characterize the thousands of species of microbes that live on or in us. So far, Jake has made half a dozen trips to Bethesda, 60 miles each way, to donate a few skin cells to the project.
Jake has been struggling with eczema since he was a few months old. The rash never stops itching, and when he scratches, it bleeds and scabs and gets even itchier. His clothes stick to the sores. He has tried many treatments, including petroleum jelly, topical steroids, antibiotics, and also dairy-free, gluten-free and probiotic diets. None of them has worked very well. When he was younger, he went to school with bandages on the tips of his fingers and slept with socks over his hands. In bed, he still sometimes lies on his back with both legs sticking straight up so they?re easier to scratch. ?I?ve never really gotten a full night?s sleep,? he says.
As many as 30 percent of all children develop eczema, and no one knows what mix of genetic and environmental factors sets it off. The disease runs in families, yet Jake?s twin sister, Becca, has perfect skin. For about 60 percent of children with the disease, it goes away by early adolescence. The others frequently deal with outbreaks for life.
Whether the rash disappears or not, nearly one third of children with eczema go on, like Jake, to develop asthma and hay fever. Asthma and hay fever also involve inflammation, but very little is known about what quirk of the immune system links them all together. ?We?ve been to pediatricians, allergists, dermatologists for years,? says Jake?s mother, Debbie, ?and nobody can figure him out.?
The average human body is made up of trillions of cells. The average human body also houses about 10 times that number of bacterial cells. Scientists have been curious about our bacterial cohabitants since 1683, when Antonie van Leeuwenhoek, using a microscope he had built himself, examined his own dental plaque only to discover ?little living animacules, very prettily a-moving.? But it has been only within the past few decades that scientists have begun to understand just how many varieties of bacteria live in or on our bodies. And now they increasingly suspect that many diseases are caused not by individual bacteria, but by the delicate interplay between multiple bacterial species and the human host.
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