Rohwer’s work with corals hints at a different type of microbial disease, one without a single obvious culprit.4 These illnesses are caused by communities of microbes, which have shifted into configurations that harm their hosts. None is a pathogen in its own right; instead, the entire community has shifted to a pathogenic state. There’s a word for such a state: dysbiosis.5 It is a term that evokes imbalance and discord in place of harmony and cooperation. It is the dark reflection of symbiosis, the antithesis of all the themes we have seen so far.
