Into the Weeds With Horse Digestive Health

Into the Weeds With Horse Digestive Health

The horse’s hind gut is home to trillions of microorganisms that work together to regulate the entire equine system and determine horse digestive health. It is estimated that 80% of the horse's entire immune system exists in the lining of the gut bacteria. The strength of the immune system relies on the horse having a rich and diverse microbiome. This richness and diversity rely on the horse eating a complex diet with a variety of plants, herbs, roots, berries and woody shrubs.

Every plant has a unique make-up that includes compounds that act in the body in a variety of ways. Not all plants are appropriate for horses, and some combinations of plants can even be toxic to horses, so it is important to do your research. This is especially important when considering adding herbs to the diet of a horse who is on medication. The following are a few from a class called “Polyphenols” that can safely and easily be added to the horse's diet to support a rich and diverse microbiome and promote horse digestive health.



Polyphenolic compounds are foods known to have antibacterial, antiviral, anticancer and antiallergic properties. The horse’s body recognizes foods high in polyphenols as being indigestible, which means they have low bioavailability compared to other nutrients like carbohydrates and proteins. Oregano, thyme and rosemary are particularly high in polyphenols known to have antimicrobials that protect the body against over-proliferation of a class of Previtallo bacteria that is linked to pathogens for disease. Approximately 5% of these plants can be broken down and absorbed in the small intestine, so 95% of the food reaches the caecum in-tact, where the gut bacteria produce enzymes to help digest them. The polyphenols that are antimicrobials are selected by the bacteria specifically to help reduce pathogenic bacteria in the horse. 

Polyphenols also help to restore and maintain the bacteria responsible for maintaining a strong gut wall which is critical to horse digestive health overall. These bacteria are fans of inulin, which is found in root vegetables like beets and carrots. The best wild plant source of inulin can be found in wild chicory.

Wild Mint is rich in oil with significant anti-microbial properties that work on wild-mint-horse-digestive-healthparticular classes of bacteria in the gut. Wild Mint contains high levels of phenolic compounds that prevent rapid digestion of starch and enzymes that reduce allergic responses and inflammation. Feed very small amounts of this to support a horse prone to laminitis.

I’ll add to this list over time so  you can grow or source some of these plants to help support a rich and diverse microbiome for your horse.