In case you were wondering, and I don’t know why you wouldn’t be, sitting alone at a sushi spot on a wet Friday night is the perfect place and time to read about the microbiome. You may not even realize how much you want to learn about microbiomes, but trust me on this, you do. And you’ll need a good spot to read. Cafés are cliche, and you need some time away from home and office. Go get sushi. For starters, you’ve got raw fish and alcohol, and you should have with you science journalist Ed Yong’s first book, I Contain Multitudes.
Consider it a biography of the microbiome, the nearly invisible world of viruses and bacteria, of archaea and protists. These are some of the oldest life forms of which we know and they are absolutely everywhere. They also have much more influence over our lives than we previously could have conceived. We’ve barely scratched the surface of what there is to know about microbiota—and every surface imaginable is covered with them.
Yong sets out to show how all the flora and fauna with which we are more accustomed “depend upon unseen organisms that they live with but are unaware of, that contribute to and sometimes entirely account for their abilities, and that have existed on the planet for far longer than they have.” In doing so he covers strange wasp behaviors, the changes in coral reefs, how deep sea worms subsist on sulphur, and of course what’s going on in the human gut.
The book is full of bizarre and fascinating factoids, but like Yong’s subtitle implies, his goal isn’t really for readers to say “oh, cool” every now and then, it’s to pause and think with more of an “oh... oh, wow.” He refrains from bombarding readers with too much information all at once (which is a feat in itself, really), giving us a chance to reflect on what we’re taking in. It’s great to learn that constantly disinfecting hospitals has made them breeding grounds for new, more potent strains of bacteria or viruses. But I’ve heard that from just reading news, and it’s likely you have as well. What I didn’t know was how that process worked or what it meant practically, and Yong explains such phenomena with verve and clarity. It turns out that the presence of other microbes in an ecosystem makes it much more difficult for problem-causers to multiply and spread without any competition for space and resources.
It seems obvious now. A similar situation can be found in your gut after a round of antibiotics (especially if you take them too often). The previous equilibrium of hundreds (thousands?) of interacting symbionts is gone. It’s not just that bacteria or viruses are automatically bad on their own, it’s that there are many species present, they are part of a larger ecosystem, and every little shift in a particular population and its interactions can have tremendous knock-on effects.
Readers versed in basic ecology will likely recognize the principle, but this kind of broad view is not particularly well known among the greater public (the exception being the Gaia principle, which is itself a vast overstatement of an ecological principle of interconnectedness).
This particular process doesn’t just happen at the microscopic level, either. The overuse of herbicides on agricultural crops (particularly on crops genetically engineered to be herbicide-tolerant) has devastated the balance of flora and fauna, leaving an ecological dead zone where natural selection has gone into overdrive and resulting in herbicide resistant “superweeds.” This is my own analogy, and Yong doesn’t get into many specifics with regard to his “grander view of life,” but there’s no way to read his work without getting curious about ecological thinking or reflecting on the ways we’ve been led to believe that microbiota cause nothing but problems. Once you start to realize that microscopic life forms have a tremendous impact on your behavior as an individual as well as the behavior of groups, well... Yong says it best: “It is a dizzying change in perspective, but a glorious one.”
