A much stronger influence is being created by environmental conditions on the mix of microbes living in various parts of your body than does competition between species.
Instead of excluding each other, microbes that fiercely compete for similar resources are more likely to cohabit the same individual.
This phenomenon was discovered in a recent study of the human microbiome - the vast collection of our resident bacteria, fungi, and other tiny organisms.
The findings were published in the early online edition of PNAS, the Proceedings of the National Academy of Sciences
. The study is one of the early steps toward a major goal of Dr. Elhanan Borenstein, the lead scientist on the project. His team hopes to build a predictive model of the human microbiome as a tool to study how medical conditions can change this massive biological system, to identify settings that promote beneficial microbiomes, and to design clinical interventions to treat currently hard-to-manage problems. For example, diet or drug therapies might be developed to manipulate the microbiome to achieve desired outcomes, such as fixing chronic digestive inflammation.
"The large communities of microbes residing on and inside us are critical to our state of health or illness," said Borenstein, a University of Washington assistant professor of genome sciences and computer science and engineering, who conducted the study with his graduate student, Roie Levy.
Borenstein explained why medical scientists are interested in the forces that structure our distinctive assemblies of microbes: This knowledge may show clinicians how to restore a more normal pattern in patients whose microbiome has been disrupted by illness, infection, toxins or injury. It can also help them better understand how disease states, such as obesity or inflammatory bowel disease, are reflected in and affected by the microbiome.