The Superorganism Revolution
The bacteria living on and in us are challenging paradigms in community ecology.
Editor's Note: This is a corrected version. For more information about the correction, please see: http://www.amsci.org/issues/pub/royal-society-misquoted.
In 1676, Antoni van Leeuwenhoek—a Dutch draper and amateur naturalist—peered through a microscope of his own design and described a world that would be misunderstood for the next 300 years. What he saw resulted in the first known description of bacteria, living beings which “were … so small in my eye…that if 100 of them lay one by another, they would not equal the length of a grain of course [sic] Sand....” No one had seen a living thing this small before.
But thanks to Robert Hooke, then Curator of Experiments of the Royal Society, incredulity gave way to acceptance. Hooke was the author in 1665 of Micrographia, the first illustrated account of microscopic observations and a likely inspiration for van Leeuwenhoek’s undertakings. In 1667, Hooke would confirm the observations of his Dutch colleague. The draper whom he called “Ingenious and Inquisitive” had seen and provided the first description of bacteria.
The existence of a living world beyond the reach of our senses is less mysterious today, but the medical profession’s attitude towards our bacterial associates has, until recently, oscillated between benign neglect and suspicious distrust.
Science is just starting to grasp the sheer abundance and diversity of bacterial life present on and in our bodies. More important, we realize that these bacteria are not simply squatters or unavoidable hitchhikers picked up as we move through a world crowded with microbes. Rather, they influence our health, digestion, metabolism, and response to medicines, not to mention our survival and evolution. The discovery of the human microbiome, the collection of microbial ecosystems that colonize virtually every external and internal body surface, has forever changed how we see ourselves. These bacteria shape our biology from birth to the grave. They are part of us.