Animal Microbiomes: The Invisible Partners That Sustain Animal Health, Productivity and One Health

Animals host dense and diverse microbial communities of bacteria, archaea, fungi, protozoa and viruses across the gut, skin, respiratory and reproductive tracts, and mammary gland. This microbiome plays a central role in digestion, immune development, growth, reproduction and disease resistance. Environmental and management factors including diet, antibiotic use, stress, housing and early-life care can alter this ecosystem. The resulting state of microbial imbalance known as dysbiosis, is associated with conditions such as diarrhoea, acidosis, poor growth and reduced productivity. This article outlines the nature and functions of animal microbiomes in ruminants, poultry, pigs, dogs and cats, honeybees and amphibians, highlighting their significance within the One Health framework, including antimicrobial resistance, food safety and methane emissions. Practical strategies to support a healthy microbiome are discussed: balanced nutrition, good early-life care, probiotics and prebiotics, prudent antimicrobial use, hygiene, stress management and microbiota transplantation. The article also highlights the role of veterinarians and the research gaps that remain, particularly for Indian livestock breeds and production systems.