| VETERINARY |
THE DIFFERENCES BETWEEN A HEALTHY/ UNHEALTHY BIOME Carol Hughes PhD
G
astrointestinal diseases and upsets are common in thoroughbred racehorses, causing discomfort, loss of performance and even mortality. Every common gastrointestinal disease can be linked back to disturbances (dysbiosis) of the gut bacteria. Currently, new gene technology is driving research at an intense rate, providing new insights into the equine microbial community (1) and providing both trainer and the vet with a powerful and accurate analytical tool to improve health and manage disease. The gastrointestinal tract of the horse is colonized by trillions of microorganisms, which includes 1,000-1,500 different species, making up around 95% of the biome; the other 5% are made up of archaea, protozoa, fungi and viruses. Though most studies concentrate on identifying species of bacteria and linking to health and disease. Other members of the biome have equally important
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Shutterstock roles to play. In the racehorse, a major player is the Enterobacteria phage PhiX174, which is a bacterial virus that protects the horse against E-coli (2). The microbial community has co-evolved with the host, performing essential and vital activities such as the extraction of energy and nutrients from foodstuff, synthesis of vitamins, interaction with the immune system and cross talk with the brain, which is thought to affect temperament and behaviour. Taxonomic and functional compositions of the gut microbiome are rapidly becoming viable indicators of horse health and disease. Each member of the microbial community has a different but synergistic role, which is beneficial to the health of the horse; e.g., the fungi break down the indigestible parts of forage plants, such as the polysaccharides, whilst the ciliate protozoa contribute to the process by producing a wide range of enzymes that the