Microbes first into the life rafts: preserving microbiomes to secure health in degrading ecosystems

All organisms on the planet intrinsically rely on microbial ecosystems, and there are increasing calls from research communities to consider microbiota when administering personal or public health, ecosystem health, and the use of microbiota in personal or environmental health remediation, such as reducing the impacts of climate change, or protecting at-risk habitats which host rare microbiota. Through our collective work on the integral nature of microbiomes to host and environmental health, on health policy, and on the development of research and policy agendas, we have previously developed the concept of 'microbiome stewardship' and guidelines to promote consideration of microbial communities broadly or in specific scenarios. The practicality of stewarding one versus many microbiota is highly contextual, and will require different strategies for different scales of conservation. Here, we provide scientific arguments for the need for microbial stewardship, examples of possible solutions scaled to different ecological challenges or conservation goals, discourse on the logistical challenges which have been cited by research communities, and opportunities to use cutting-edge microbiome concepts and technology to implement large-scale interventions.