Human-dog co-residence proposed to epigenetically shape human stress, immune, and socio-emotional regulation

Despite at least 20,000 years of human-dog coexistence, the biological consequences of this sustained interaction remain poorly understood. Current research often overlooks the potential for multispecies living environments to act as a significant biological exposure. This gap limits our understanding of how long-term social and ecological relationships might influence fundamental aspects of human regulatory biology, particularly in areas like stress regulation, immune function, and socio-emotional neurobiology. Investigating environmentally responsive epigenetic mechanisms offers a novel avenue to explore these profound, yet uncharacterized, biological impacts.

This commentary integrated evidence from diverse fields including genomics, neuroscience, microbiome research, evolutionary anthropology, and palaeoepigenetics. The authors synthesized existing knowledge to examine whether multispecies living environments represent an under-recognized biological exposure shaping human regulatory biology. They further outlined a framework to test whether archaeologically inferred dog co-residence is associated with epigenetic and regulatory signatures in ancient human populations, while accounting for major ecological and demographic confounds. The approach involved defining an epigenetic imprint as detectable differences in gene-regulatory marks, such as DNA methylation at environmentally sensitive loci.

The commentary proposes that sustained exposure to dogs may have contributed to context-dependent variation in human stress regulation, immune function, and socio-emotional neurobiology. This influence is hypothesized to occur through environmentally responsive epigenetic mechanisms, specifically through detectable differences in gene-regulatory marks like DNA methylation at environmentally sensitive loci. These proposed epigenetic imprints are consistent with developmental plasticity and early-life environmental calibration, rather than germline inheritance. The authors argue that human-dog cohabitation offers a plausible and testable model for investigating how long-term social and ecological relationships may influence stress and immune regulation across populations. > Overall, the work argues that multispecies living environments may represent an under-recognised biological exposure shaping human regulatory biology through epigenetic mechanisms.