In June of 2012, a coordinated press release, along with articles appearing in the journal Nature and the Public Library of Science, The Human Micro Biome Project (HMP) released the first volume of data ever to map the boundaries of normal microbial variation in humans. This is an historic milestone for the HMP and the world of medical science, as before they published their study, the volume of microbes living in the human body and their genetic composition was largely unknown. Though they directly influence our health, and it is widely recognized that we cannot live without them, they have been, for the most part, ignored by medical science. Thanks to the HMP, those days have come to an abrupt and enlightening end.
Microorganisms living in our bodies outnumber human cells 10 to 1, though they make up only 1 to 3 percent of the mass. For an average human being this is 2 to 6 pounds of microorganisms that are vital for human health and before the Human Microbiome Project, virtually unknown to medical science. Previously only a few hundred bacterial species were known to medical science, mostly disease causing pathogens. The Human Microbiome Project has identified more than 10,000 symbiotic microbial species including those previously thought of only as pathogens, which can now be observed behaving symbiotically with the human body.
The human body carries 22,000 protein-coding genes while our newly acknowledged microbiome contains 8 million unique protein coding genes, 360 times more than the human genome. The Human Microbiome’s genomic contribution is what provides us with the ability to digest food, making proteins, fats and carbohydrates available to the blood stream as well as generating complex compounds from them, for example, swelling during bacterial infection is regulated by an anti-inflammatory compound produced by microorganisms living within the body. These organisms are diverse, yet specialized to the environment of the human body, with several species capable of performing the same metabolic function, such as breaking down fats. Though they live out a lifecycle within the company of similar organisms, they do not appear to compete, instead working to reach a state of equilibrium with metabolic functions.