How do anthropogenic changes affect wildlife microbiomes?

Human activities are transforming ecosystems, but their effects on wildlife microbiota remain poorly understood. Pollution, habitat transformation, and altered host contact networks can reshape host-associated microbiota in context-dependent ways, including through symbiont loss, selection for antimicrobial resistance, shifts toward human-associated community states, and increased among-host variability. Whether these changes are transient or persistent, harmful or adaptive, or consequential for wildlife health and disease risk is largely unknown. This Unsolved Mystery highlights key mechanistic gaps and outlines future research strategies for the field, including studies that distinguish environmental filtering, dispersal limitation, host physiological responses, and cross-species microbial transmission.