Zusammenfassung
When a new human being emerges from its mother, a new island pops up in microbial space. Although a human lifespan is a blink in evolutionary time, the human island chain has existed for several million years, and our ancestors stretch back over the millennia in a continuous archipelago. Microbes thrive on us: we provide wonderfully rich and varied habitats, from our UV-exposed, oxic and desiccating skin to our dark, wet, anoxic and energy-rich gut that serves as a home to the vast majority of our 100 trillion microbial (bacterial and archaeal) partners. A sobering or inspiring fact: we contain 10 times more microbial than human cells and an estimated 100 times more microbial genes. How our association with microbes has evolved, the forces that shape it, what about it might be uniquely ‘human’, how changes in our biosphere are affecting it, and how it impacts our health, all are challenging questions for the future because they require a level of engineering and computational sophistication that is still emerging. Our crystal ball sees the epidemiologist of the future describing how changes in kilometre-scale macro-ecosystems affect micrometer-scale microbial ecosystems associated with populations of meter-scale human beings, on time scales of an infection, a human lifespan, or the rise and fall of a society.