We like to think we’re in charge of our health, but it increasingly looks like the ones really running the show are the microbes in, on, and around us - and not just the ones that cause diseases. Bacteria and other microbes on our skin and in our intestines far outnumber our actual human cells, and are responsible for a large fraction of what our bodies do - from digestion to mental health.
Jack Gilbert, a microbial ecologist at Argonne National Laboratory and the Marine Biological Laboratory, says we're not so much individuals as ecosystems. If that idea is bit off-putting, though, you could just think of your microbiome (that's the latest buzzword for your collective microbes) as another bodily organ - one that needs to be supported and maintained.
Gilbert says that requires a pretty dramatic shift in our attitudes toward microbes. Over last century or so, a lot of attention and effort has been focused on eliminating disease-causing microbes - first with hygiene measures, then vaccines and antibiotics. Today, there are antimicrobial hand soaps, toothpastes, clothes, and countertops. Washed down drains and flushed down toilets, the antimicrobial, triclosan, has become one of the most common contaminants in aquatic environments.
Deaths due to bacterial illnesses have dramatically decreased – a good thing, to be sure. But Gilbert says we tend to overestimate the risk of a microbe making us sick, and there are side-effects to our widespread combative actions: we're killing a lot of good bacteria, and promoting the rise of antibiotic-resistant bacteria. The fact that we’ve become a largely indoor species hasn’t helped. Gilbert says we’d do well to worry less about killing the microbes that make us sick and more about acquiring and supporting the ones that make us healthy, and even help us fight off the bad ones.
Gilbert has changed his own lifestyle to optimize his bacteria. Dogs bring the outdoor element into the home (cats not as much so, as they tend to be indoor pets) and share microbes liberally via snuggling and licking, so Gilbert got a dog. He started exercising more – outside. He also changed what – and when – he ate, and he worries less about hand-washing than he did.
While he hesitates to hand out advice – and cautions against experimenting on oneself – he encourages everyone to stay informed, worry less, and get outside more.