A paper in the Feb. 2 issue of Science reports the use of new molecular technologies for unraveling the age-old mystery of the relationships between ourselves and the microbes that live in our body. The study reveals that microorganisms in the gut influence the expression of a number of genes that are important to intestinal development and function.
"We live in a world predominated by microbes," explains Jeffrey I. Gordon, M.D. "These organisms have co-evolved with their mammalian hosts over millions of years. During this time, they have been forced to become master physiologic chemiststhey have had to develop strategies for satisfying their own nutritional needs and various needs of their hosts. We wanted to figure out some of the lessons that they have learned about us, and how they contribute to our health."
Gordon, who led the study, is the Alumni Professor and Head of the Department of Molecular Biology and Pharmacology at Washington University School of Medicine in St. Louis. The first author is Lora V. Hooper, Ph.D., an instructor in molecular biology and pharmacology and a recipient of a career development award from the Burroughs Welcome Fund.
The human intestine contains the largest society of friendly microbes in the body. The total number of these microbes may be equal to the total number of cells in our body. Given its large microbial society, the intestine is the best place to turn when trying to understand how friendly bacteria affect our genes. These bacteria dont simply sit and wait to be fed by the nutrients we consume. Instead, they actively shape our biology so that they can establish and maintain homes for themselves.
The researchers addressed the general question of how microbes and humans co-exist using mice as a model system. After raising mice in a germ-free environment, they inoculated the animals with Bacteroides thetaiotaomicron, a bacterium normally found in healthy human and mouse intestines. Using two relatively new
Contact: Gila Reckess
Washington University School of Medicine