Lettuce alerts show the limits of our power
It’s time to change the way we think about microbes, Maya Hey says.
In the wake of the most recent romaine lettuce E. coli warning, you may have sworn off Caesar salads and bleached out all potential life forms in your fridge’s vegetable drawer. Next time, you may well do likewise. Yes, it’s a safe bet that there will be a next time. It’s wrong to believe that we can control microbial life, because microbes are both everywhere and invisible. When food scares strike, we are painfully reminded that food policies and public health codes are not enough to prevent these outbreaks. So, what are we to do? We need to change the way we think about how we live with microbes. When outbreaks happen, government institutions often declare that they will look for the “root cause” in order to prevent repeat occurrences. They tend to look for contamination and poor hygiene in farms, facilities and restaurants in order to trace back to a “ground zero” lettuce. But, in the most recent outbreak, no common grower, supplier, distributor, or brand of romaine lettuce has been definitely identified. In fact, searching for the “ground zero” agent of tainted lettuce (or eggs or any other food) overlooks one crucial advantage bacteria have over humans: bacteria swap DNA much more easily than do humans. They thrive because they can constantly adapt to their environments, and they persist because they can evolve more quickly than humans can enact policy. The actual root cause of food alerts and recalls may be our own thinking that we have power over microbes and can eliminate them at will. We need to change the way we think about microbes as just good or bad entities. Thinking of microbes as friendly/probiotic or unfriendly/pathogenic classifies them in relation to the human eater, when their potential to help or harm can be a question of context. We cannot control microbes, even though we think we do with hand sanitizer, pasteurization and antibiotics. These practices are based on the failed logic of eliminating all microbes first, and then only letting the “good” ones live. Every act of sterilization creates an opportunity for bacteria to mutate, because if one survives eradication, that bacterium passes its resistant genes with a process similar to bacterial high-fives. The staunch belief that our technologies will save us is hubris, for we are inadvertently creating the conditions for bacterial resistance. We need to rethink our place in this microbial
They persist because they can evolve more quickly than humans can enact policy.
world. We may subscribe to a popular myth that we are at the top of a proverbial food chain, yet how quickly our primacy unravels when we encounter something like undercooked mussels. We are not immune to their toxins, just as they are not immune to our technologies. We are bigger than they are, yes, but they outnumber us. To be sure, some species are pathogenic to humans no matter what the context. This leaves the onus of prevention on individual actions, and it also leaves out nuance. So do avoid the romaine lettuce for now, keep washing your hands, and take antibiotics as prescribed. But go one step further and think about microbes as more than just harm and not-harm. We cannot live a life without microbes. The good news is that humans and microbes have been living together for millennia, even though we may not think about them often or in detail. But, it is precisely this “out of sight, out of mind” mentality that got us into the mess of rapid mutations, resistance, and needing to “fight back.” We do not need to fight them; we need to understand them better. We need microbes for our health and physiology as well as for our soil and sustainability. We need to stop thinking about how we have more power than microbial life, and consider how we relate to them on a day-today, plate-to-plate basis.