What’s bugging you?

The human population of planet Earth is over 7 billion.  While that’s a lot of people, the number pales in comparison to the population of microbes in and on a single human body, a figure about 15,000 times larger.  The average healthy human hosts one hundred trillion microbes and can attribute between thirty-two and eighty ounces of their total weight to the tiny tenants.  A week on intravenous Lysol won’t put you back in your high school 501s but it’s good to know there’re a few pounds that can be justifiably denied.

Before you rub down with alcohol or drink Purell you should know the vast majority of the tiny fellows spend their lives supporting yours.  Sure, some are just along for the ride and others are nasty little pathogens looking for their chance to harass, but without the trillions of tiny critters we’d be headed for a miserable death.

If you’re interested in knowing who you’re hosting you can check out the Public Library of Science’s Human Microbiome Project Collection.  Recently the initial phase of the project finished mapping the full community of microbes that inhabit healthy humans and providing a broad baseline of microorganisms found in 18 different areas of the human body.

In their five year mission (to go where no man has gone before?) 200 scientists at 80 institutions sequenced the genetic material of bacteria taken from over 200 healthy people.
 
They discovered as many as a thousand bacterial strains in each person. And, interestingly, each person’s collection of microbes was different from the next person’s; we’re our own bacterial planet. They also found evidence of potential disease-causing bacteria lurking in everyone’s microbiome but living peacefully among their miniscule neighbors.

How infested are we with microbes? According to Dr. Lita Proctor, program director for the Human Microbiome Project, “The gut is not jam-packed with food; it is jam-packed with microbes,” Dr. Proctor said. “Half of your stool is not leftover food. It is microbial biomass.”  Huh, no sh…kidding?

According to the PLoS website, “The healthy adult body hosts ten times as many microbial cells as human cells, including bacteria, archaea, viruses, and eukaryotic microbes resident on nearly every body surface.”  You’ll want to keep in mind, all those cells are much smaller than human cells, sort of like minnows compared to sharks.

Dr. David Relman, a Stanford microbiologist, compared a human body to a coral reef, “an assemblage of life-forms living together.”  We’re not unlike planet Earth, one entity with masses of life in every nook and cranny. It’s only because we couldn’t see them that we never realized they’re there.

Traditionally, we think of bacteria as bad, and some are, but many are essential for human health.  With plenty of dirty little critters out there waiting to bring you down a notch it’s best to keep those hands washed, but farming the good ones is essential.  The better job you do the healthier you’ll be.  So now you know what’s bugging you.