Scientists, policymakers and the public are becoming increasingly aware that biodiversity loss, climate change, deforestation and pollution are causing profound disruptions to Earth’s ecosystems. But every animal and plant that makes up these ecosystems could also be considered a diverse ecosystem in their own right, with each providing a home to a little-explored, invisible community of microbes — living both on, and inside every individual — known as the microbiome. Today, as microbiome research extends beyond biomedical applications into conservation and ecology, scientists are finding unse…