The gut-brain axis and microbiome composition are emerging as important welfare factors in multiple species, with microbiome disruption linked to anxiety, pain sensitivity, and behavioral abnormality.
The emerging field of welfare microbiomics offers new insights into how gut health mediates welfare outcomes across species. Animals experiencing chronic stress develop microbiome disruption that amplifies stress sensitivity — a feedback cycle that compounds welfare harm. Welfare interventions targeting microbiome health — through prebiotic and probiotic strategies, reduced antibiotic use, and stress minimisation during sensitive periods — may improve welfare outcomes beyond what direct behavioral interventions achieve. The science is early but the implications for farm, zoo, and companion animal welfare are significant.