Fructans in Equine Diets: Fermentation Studied

Equine nutritionists and researchers know fructans should be fermented exclusively in the hindgut—the cecum and colon. New research, however, shows that the breakdown, but not necessarily the digestion, of fructans can actually start in the stomach depending on the type of forage a horse is offered.

“According to a group of European researchers, this study and others like it are important because many diseases in horses are caused by misunderstood nutrition principles.^* By enhancing the knowledge of how different feedstuffs are broken down, digested, and fermented, horses can be fed to not only prevent disease but also maximize performance,” relayed Catherine Whitehouse, M.S., a nutrition advisor for Kentucky Equine Research (KER).

To understand the importance of the key study finding–that fructan breakdown by stomach acid occurs and fructans may not be fully intact when they reach the hindgut–a few fructan facts should be noted:

• Fructans are long chains of individual sugar molecules linked together. Plants produce fructans as a storage form of energy.
• When consumed, fructans were historically thought to pass through the stomach and small intestine, reaching the hindgut essentially unadulterated. Only then did they undergo fermentation.
• The process of fermentation produces energy for horses and occurs only in the hindgut using the microbes that reside there. Fermentation is markedly different than digestion, which is the process of breaking down sugars and proteins via enzymatic degradation in the stomach and small intestine.
• Fructan fermentation serves as an important energy source, but too much fructan in the diet can contribute to hindgut acidosis and laminitis.

The research conducted by Strauch and coworkers shows there is more to learn about fructans and their impact on horse health.

“Some horses are extremely sensitive to the fructans in forages, causing risky shifts in the pH of the hindgut. A time-released hindgut buffer such as EquiShure helps maintain a stable pH in the cecum and colon to maximize fermentation and minimize the development of life-threatening laminitis,” recommended Whitehouse. “Maintaining a fairly consistent pH in the hindgut is especially important for horses that have known metabolic problems.”

^*Strauch, S., B. Wichert, J.M. Greef, et al. 2017. Evaluation of an in vitro system to simulate equine foregut digestion and the influence of acidity on protein and fructan degradation in the horse’s stomach. Journal of Animal Physiology and Animal Nutrition (Berl). 101 Suppl 1:51-58.