Researchers also want to know whether people are born with these bacterial colonies or develop them after birth, through external contact with their mothers and during the delivery process. Even more fascinating is why each person has his or her own blend of bacteria -- much like a fingerprint. Perhaps diet, climate, locale or a combination of variables are responsible for each person's unique bacterial make-up, said Fierer.
Most important, researchers want to know how the colonies impact health and whether they can be harnessed in some way to treat disease. In the future, for example, microbial mapping could lead to routine screening of patients as a way to record a baseline of their normal microbial communities. Any later deviation could be a sign of disease.
"Our ultimate goal is to devise strategies for personalized medicine, based not on the human genome, where we are all 99.9 percent identical, but on the human microbiome, where we are 80 to 90 percent different from one another," added Knight.
There's more on the biology and health-care potential of microbial communities at the U.S. National Institutes of Health.
SOURCES: Noah Fierer, Ph.D., assistant professor, microbial ecology, University of Colorado at Boulder; Robert Knight, Ph.D., assistant professor, chemistry and biochemistry, and computer science, University of Colorado at Boulder; Nov. 5, 2009, Science, online