Mapping the human microbiome

The variety of microbes living in and on the human body is revealed by the most comprehensive inventory yet of the body’s microbial community. Reported online November 5 in Science, the research provides one of the most thorough whole-body maps to date of the estimated 100 trillion individual microbes the body harbors inside and out.

Assessing the body’s different microbial habitats will help researchers understand the intimate link between the human body and the microbiome — the bacteria, fungi and viruses that live in and on the body. These microbes — estimated to outnumber human cells by at least a factor of 10 — usually coexist with the human body in peaceful harmony, playing important roles in health, such as aiding digestion and preventing harmful infections. Understanding which microbes live where may help scientists understand how to treat people with disorders, including eczema and digestive disorders, that have been linked to specific kinds of bacteria.

Comparing the bacterial profiles of volunteers to each other, the researchers found that overall, the microbiomes were highly personalized. Places such as the gut, hair, nostrils, ear canals and skin locations were very different from person to person. “People seem to be colonized by very different bacteria,” Rob Knight, one of the researchers who led the study, says. The researchers also monitored how bacteria communities changed in people over time. As expected, bacteria in the relatively isolated belly button remained fairly constant over the three months of the study. But bacteria in other regions also remained fairly constant over time, Knight says, supporting the idea that people have resilient, predictable “biogeographical patterns” of bacteria.

See the complete article by Laura Sanders at ScienceNews : http://www.sciencenews.org/view/generic/id/49242/title/Bacteria_flourish_in_favorite_ecosystems_on_the_human_body,_new_map_shows

The research mentioned in this article has been published online 5 November 2009 in /Science /Express Reports:

Bacterial Community Variation in Human Body Habitats Across Space and Time
Elizabeth K. Costello, Christian L. Lauber, Micah Hamady, Noah Fierer, Jeffrey I. Gordon, and Rob Knight
DOI: 10.1126/science.1177486
http://www.sciencemag.org/cgi/content/abstract/sci;1177486v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=rob+knight&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT