Microbiome stewardship: definition and guiding principles for implementation.

Microbiomes are essential for ecosystem, plant, animal, and human health. There is accumulating evidence that changes to microbiomes from anthropogenic activities are associated with adverse health outcomes. Despite this evidence and calls for action, almost no oversight mechanisms exist to protect microbiomes or their key functions, in part due to uncertainty about what to protect, and how. We have previously proposed microbiome stewardship as a foundational concept that can act across policy domains to facilitate the ongoing presence of key microbial communities and their functions. The purpose of this article is to provide a working definition of microbiome stewardship and develop guiding principles to support its implementation. The concept of microbiome stewardship is relevant to a wide range of policy domains, such as public health, clinical care, environmental protection, food production, and agriculture. Nonetheless, the implementation of microbiome stewardship will be highly specific, as it needs to be guided by considerations of microbial habitat, objectives of stewardship, and available opportunities for intervention. Accordingly, aligning stewardship responsibility with specific institutions and governance mechanisms will be context-dependent. We conclude with a discussion that situates microbiome stewardship relative to other initiatives.