Research into the gut microbiome of farm and companion animals is revealing connections between intestinal bacteria, immune function, and disease that have significant implications for animal welfare and agricultural practice.
Gut microbiome research is connecting animal welfare directly to health outcomes through the mechanism of stress-induced microbiome disruption. Animals experiencing chronic welfare failures -- overcrowding, social stress, poor housing -- show altered microbiome composition that reduces immune function and increases disease susceptibility. This means poor welfare is self-reinforcing: stressed animals get sick more, require more antibiotics, which further disrupts their microbiome. Microbiome-targeted interventions including probiotics and faecal transplantation can help, but the most effective welfare intervention remains addressing the underlying housing and social conditions that cause chronic stress.