It starts with the gut. The environment of the intestine (a.k.a. gut) contains naturally occurring beneficial microorganisms commonly called  ‘bugs’. Gut bugs are found in all species, including humans, and are essential to the digestion process. For the horse, gut bugs work to break down components of forage and feed as they pass through the digestive tract.  The bugs deconstruct complex molecules within feedstuffs, which releases nutrients and allows the synthesis of energy substrates and important vitamins. Those nutrients are then absorbed through the intestines into the bloodstream, where they become available to cells in the body to support basic maintenance, growth and activity.

Feed that is broken down and digested more completely allows for more nutrients to be readily available for absorption.  This is essentially what probiotics do. Adding probiotics to a horse feed means adding more beneficial bugs to the existing population in the horse’s gut. Probiotics such as yeast culture, work with the naturally occurring bug population to enhance the digestive process, further breaking down complex protein and fiber fractions in the gut and making them more available for absorption into the blood stream. As a probiotic, yeast culture has also been shown to balance and stabilize the digestive microbial ecosystem in the cecum of the horse, as well as help prevent the colonization of bad bacteria in the gut.  A stable microbial ecosystem is beneficial to the horse beyond improvements in digestive and absorption efficiency, it also reduces the risk of digestive upset, such as gas colic, that a horse might experience with changes in feed or hay, or while under stress from transportation, shows, changes in weather or other.

Prebiotics can be thought of as an energy jolt for the gut bugs.  Prebiotics are a rich nutrient source for the gut bugs (e.g. lactobacilli, bifidobacterial) which in turn stimulates their growth and activity, making them more effective at their job. Research has shown that prebiotics help stabilize the population of gut bugs even through sudden changes in the diet, which helps to reduce incidents of digestive upset.  For performance horses who require energy dense diets that include higher levels of starches and sugars, prebiotics can help reduce the incidence of digestive disorders and support optimal performance.  Prebiotics such as inulin and oligofructose are selectively fermented by the gut bugs, stimulating their growth and activity, which benefits the horse by enhancing the absorption and retention of certain minerals, which in turn can support the immune system, skeletal tissue, and more.

The population of bugs in the gut are sensitive to changes in their environment brought on by stress, illness or the ingestion of undesirable materials .The addition of pre- and probiotics to a diet has been shown to be beneficial in reducing the incidence of digestive upset, namely diarrhea. For senior horses, the use of pre- and probiotics in feeds has been shown to improve the digestibility and absorption of nutrients, which can translate into an enhanced quality of life.  In summary, pre- and probiotics work with the naturally occurring gut bugs to support optimal gut health, aid in the digestion process, as well as provide a buffer against negative bacteria.