The National Institutes of Health (NIH) has awarded scientists at Washington University School of Medicine in St. Louis four grants totaling $19 million to explore the trillions of microbes that inhabit the human body and determine how they contribute to good health and disease.
The grants are part of the Human Microbiome Project, an ongoing, ambitious effort to catalog the bacteria, viruses, fungi and other microorganisms that naturally coexist in or on the body. In all, the NIH today announced $42 million in grant awards to 12 U.S. institutions that expand the scope of the microbiome project.
The largest chunk - $16 million - goes to Washington University's Genome Center, which played a central role in the initial phase of the project. In the new effort, WU genome scientists, led by George Weinstock, Ph.D., will decode the DNA of about 400 microbes in collaboration with scientists at three other large-scale DNA sequencing centers. This information will then be used to catalog the microbes found in samples from healthy human volunteers to find out which microbes live in various ecological niches of the body. Samples will be collected from the mouth, skin, nose, vagina and digestive tract.
Many scientists consider humans as superorganisms, a synergistic community of both human and bacterial cells that is more than the sum of its parts. The microbial cells in the human body are major players: they outnumber human cells by at least 10 to 1. Moreover, our bodies carry more than 100 times as many microbial genes as human genes. These microbes contribute essential functions that humans have either lost or never been able to perform on their own, such as synthesizing certain vitamins, digesting complex sugars, or helping the body to ward off harmful disease-causing microorganisms.