On Dec. 19, 2007, the Human Microbiome Project (HMP), a $150 million initiative, was established by the National Institutes of Health with the mission of generating resources that would enable the comprehensive characterization of the human microbiome and analysis of its role in human health and disease.

The HMP is the collection of all the microorganisms living in association with the human body, including eukaryotes, archaea, bacteria and viruses. Bacteria in an average human body number ten times more than human cells, for a total of about 1000 more genes than are present in the human genome.