Harnessing soil biodiversity to promote human health in cities

Biodiversity is widely linked to human health, however, connections between human health and soil biodiversity in urban environments remain poorly understood. Here, we stress that reductions in urban soil biodiversity elevate risks to human health, but soil biodiversity can improve human health through pathways including suppressing pathogens, remediating soil, shaping a beneficial human microbiome and promoting immune fitness. We argue that targeted enhancement of urban soil biodiversity could support human health, in both outdoor and indoor settings. The potential of enhanced urban soil biodiversity to benefit human health reflects an important yet understudied field of fundamental and applied research.