The Body’s Ecosystem:
Research on the human microbiome is booming, and scientists have moved from simply taking stock of gut flora to understanding the influence of microbes throughout the body.
by The Scientist Staff
The human body is teeming with microbes—trillions of them.
The commensal bacteria and fungi that live on and inside us outnumber our own cells 10-to-1, and the viruses that teem inside those cells and ours may add another order of magnitude.
Genetic analyses of samples from different body regions have revealed the diverse and dynamic communities of microbes that inhabit not just the gut and areas directly exposed to the outside world, but also parts of the body that were long assumed to be microbe-free, such as the placenta, which turns out to harbor bacteria most closely akin to those in the mouth.
The mouth microbiome is also suspected of influencing bacterial communities in the lungs. Researchers are also examining the basic biology of the microbiomes of the penis, the vagina, and the skin.
Altogether, the members of the human body’s microbial ecosystem make up anywhere from two to six pounds of a 200-pound adult’s total body weight, according to estimates from the Human Microbiome Project, launched in 2007 by the National Institutes of Health (NIH)…
(read more: The Scientist)
illustration by Paul Wearing