The equine gastrointestinal microbiome consists of a diverse community of microorganisms throughout the horses digestive tract that work together to support digestion, health, and behavior. When that system stays in balance, everything typically runs smoothly, and the horse might appear healthy. When it becomes unbalanced, the horse can develop a variety of illnesses. Read on to better understand the horses GI microbiome and how you can help keep it (and, in effect, your entire horse) healthy.Where Do Microbes Work?Foregut (stomach and small intestine) Digest starches, simple sugars, fats, and proteinsMicrobe imbalances can cause equine gastric ulcer syndrome (EGUS)Hindgut (cecum and large intestine) Ferment complex fibers such as cellulose and hemicelluloseSupply more than 50% of daily energyMicrobiome BalanceA horses GI microbial balance varies due to:Diet and forage qualitySeasonal changesAgeStress and managementDisease and antibiotics (antibiotics can disrupt both harmful and beneficial microbes)What is the Horses Microbiome-Gut-Brain Axis?This bidirectional communication network connects the horses digestive health with mood, behavior, and cognitive functions. High- starch diets can disturb the microbial balance, which might show as:ReactivityNervousnessAggressionIf the gut microbiome becomes imbalanced the horse could show the following signs:Gastric ulcersDiarrheaColic/colitis (abdominal pain or inflammation of the large or small colon, respectively)Laminitis (inflammation of the tissue that suspends the coffin bone within the hoof)Reduced immune functionSupporting a Healthy Gut MicrobiomeAdjusting the horses environment and management strategies can help balance the gut microbiome and keep it balanced. This includes several factors:NutritionEmphasize forage and fiber in the dietMake dietary changes gradually over about two weeksSupplementsPrebioticsProbioticsPostbioticsManagementReduce the horses stressProvide plenty of turnout and pasture timeMonitor the horses feed intake and subsequent behavior changesTake-Home MessageHealthy gut microbes support the horses digestion, behavior, and overall health. To help keep the horses microbiome in balance, avoid rapid diet changes, manage stress where you can, watch for early signs somethings off, and contact your veterinarian if you see any problems.