Within the body of a healthy adult, microbial cells are estimated to outnumber human cells ten to one. This community, however, remains largely unstudied, leaving their influence upon human development, physiology, immunity, and nutrition almost entirely unknown. To take advantage of recent technological advances and to develop new ones, the NIH Common Fund Human Microbiome Project (HMP) was established with the mission of generating resources enabling comprehensive characterization of the human microbiota and analysis of their role in human health and disease.
Traditional microbiology has focused on the study of individual species as isolated units. However the vast majority of microbial species have never been successfully isolated as viable specimens for analysis, presumably because their growth is dependent upon a specific microenvironment that has not been, or cannot be, reproduced experimentally. Advances in DNA sequencing technologies have created a new field of research, called metagenomics, allowing comprehensive examination of microbial communities, even those comprised of uncultivable organisms. Instead of examining the genome of an individual bacterial strain that has been grown in a laboratory, the metagenomic approach allows analysis of genetic material derived from complete microbial communities harvested from natural environments. In the HMP, this method will complement genetic analyses of known isolated strains, providing unprecedented information about the complexity of human microbial communities.
The NIH Human Microbiome Project is one of several international efforts designed to take advantage of metagenomic analysis to study human health. The HMP expects to continue the practice established by the Human Genome Project of international collaboration to generate a rich, comprehensive, and publicly available data set. This information will be available worldwide for use by investigators and others in efforts to understand and improve human health. For more information on the Human Microbiome Project, e-mail HMPinformation@mail.nih.gov or visit http://www.hmpdacc.org .