“NO MAN is an island,” wrote John Donne. He was thinking of the wider society of which every human being is a member, but it is also true that human bodies themselves are societies. Besides the 10 trillion human cells in a body, there are another 100 trillion bacterial cells. These bacteria are symbiotic with their human hosts—drawing sustenance from them, but also giving something in return by performing chemical transformations that human cells cannot manage and safely occupying ecological niches that might otherwise be colonised by pathogens. Together, the numerous species that make up this luxuriant community are estimated to contain about 100 times as many genes as the human genome proper. The exact details of this “supplementary” human genome are, however, unknown.

This should soon change. At a meeting held last week in Bethesda, Maryland, a team of researchers organised by Jane Peterson and Lu Wang of America’s National Human Genome Research Institute unveiled their plan for a Human Microbiome Project…One question the project would address is the degree to which the human microbiome is, indeed, uniquely human, and how the various host-microbe relationships have come about. Another is whether a set of bacteria is essential for basic human physiology—in other words whether humans really are symbiotic creatures who would die without their collaborators.

Link

Related Leave a Comment