15 June 2012
The project, funded by the US National Institutes of Health, is one of a number of international efforts to comprehensively catalogue, characterise, and sequence the full range of microbes that live in and on the human body. Microbial cells are estimated to outnumber human cells by an order of magnitude in a healthy person, and are thought to play a significant role in human development and health.
HMP takes a metagenomic approach; that is, cataloguing and analysing genetic material collected directly from natural environments, rather than cultivated in the lab (see earlier PHG Foundation news for a description of the project and discussion of its milestones and ethical implications).
The project has now identified and sequenced more than 10,000 microbial species collected from 300 healthy volunteers. They believe these to represent the vast majority of bacterial species that are associated with people in good health.
Their findings indicate that microbiomes vary both by region of the body and between individuals, but tend to remain stable in a given person over time. Despite the exact species varying between people, those at the same sites tend to carry similar genes and perform equivalent metabolic functions, such as digesting sugars in the mouth. NHGRI Director Eric Green said these latest publications should be viewed as the initial analyses of a very large data set.
Among the studies published this week by the HMP are ones documenting and validating the methods used, cataloguing the metabolic and immunity genes within human microbiomes, and evaluations of the gut and nasal microbiomes in relation to disease. The ultimate goal is to understand the microbiome well enough to be able to read and tweak it to maximise health.