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Monday, June 7, 2010

The Human Microbiome Project

Now that The Human Genome Project is complete, researchers at the National Institutes of Health have been busily working on The Human Microbiome Project (HMP). The goal: to map and analyze the genomes of every type of microbe that makes its home in or on our bodies. Since the study began in 2008, 178 microorganism genomes have been published.

Microbes coat every surface of our bodies, both internally and externally. By some estimates, the cells in or on our bodies containing microbial DNA outnumber the cells containing human DNA by ten to one. Many of these microbes have never been identified, let alone studied, because they cannot be grown in laboratory settings. In the old days, like when I was in graduate school, you had to have a fairly large supply of DNA to get an accurate sequence. Today, tiny amounts will do, allowing scientists to successfully map genomes that were once inaccessible.

This illustration shows the body sites that will be sampled from volunteers for the Human Microbiome Project, part of the National Institutes of Health's Roadmap for Medical Research.
Credit: NIH Medical Arts and Printing

The researchers use samples collected from the digestive tract, mouth, skin, nose and vagina of volunteers. When the five-year study is completed, scientists expect to have sequenced about 900 different genomes, from bacterial, viruses and fungi. They will then be able to use their microbe library to compare the fauna of healthy versus sick people for a great number of conditions.

The HMP has already yielded useful information. For example, the HMP collection contains almost 30,000 previously unknown proteins. Two interesting things about this: one, that’s already more than the total number of genes in the human genome; and two, that’s double the number of novel proteins found in other public microbial databases. In other words, the HMP is proving to be a treasure trove of unique enzymes and proteins. For this reason, comparing the microbes of healthy and sick people could be tremendously useful in future diagnoses and treatments.

For those who are so inclined, you can browse the completed genomes here.