In a tremendous article in The Smithsonian Magazine, Richard Conniff writes about the largely unexplored oodles of microorganisms that make us what we are. The article overflows with wonderful facts: for instance, that there are 150 microbial species, on average, behind your ear, and 440 on the inside of your forearm. Not to mention the several thousand in your intestines, which of course I just mentioned.
“We tend to think that we are exclusively a product of our own cells, upwards of 10 trillion of them. But the microbes we harbor add another 100 trillion cells into the mix. The creature we admire in the mirror every morning is thus about 10 percent human by cell count.”
This is amazing stuff to think about. Philosophically speaking, it forces us to wonder what it means to be human. It’s not just about that bit of human DNA we have, that causes us to make our human cells. If we didn’t share space with all these other microorganisms, we would not exist.
But this is incredibly important stuff for medical experts to understand, too. Every time we give someone an antibiotic, we kill hundreds of thousands or even millions of microorganisms that make that person part of what they are. We are messing with a very complex group of organisms. Keep your eyes out for what scientists learn about this topic over the next couple decades.