WOODS HOLE, MASS. The landmark publication this week of a "map" of the bacterial make-up of healthy humans has deep roots in an unexpected place: the ocean.
Microbial communities that live on and in the human body, known collectively as the microbiome, are thought to have a critical role in human health and disease. Five years ago, the National Institutes of Health launched the ambitious Human Microbiome Project (HMP) to define the boundaries of bacterial variation found in 242 healthy human beings.
"In order to understand what sick is, it's helpful to define the healthy microbiome first," says MBL scientist Susan M. Huse, lead author of one of the HMP reports published this week.
The project's 200 scientists from 80 institutions, including Huse and Mitchell Sogin from the MBL, faced the daunting task of making sense of more than 5,000 samples of human and bacterial DNA and 3.5 terabases of genomic data.
The solution? The HMP adopted several, state-of-the-art genetic sequencing and analysis methods, many of which were originally developed by the MBL for the International Census of Marine Microbesa massive, ten-year project that yielded the first inventory of microbial diversity in the world's oceans.
And, perhaps not surprisingly, the HMP discovered that microbial distributions in the human body are not so different from those in ocean ecosystems.
Whether in the human gut, mouth, or vagina, the Pacific Ocean or the Sargasso Sea, microbial communities contain a few highly abundant bacterial types plus many, many more low-abundance types (the so-called "rare biosphere," a phenomenon first discovered in ocean samples by Sogin and his MBL colleagues).
"The more closely we look, the more bacterial diversity we find," Huse says. "We can't even name all these kinds of bacteria we are discovering in human and environmental habitats. It's like trying to name all the stars." HMP researchers concluded t
|Contact: Diana Kenney|
Marine Biological Laboratory