Supporting the Microbiome: Potential of Prebiotics

Prebiotics fuel the microbes in the hindgut, thereby promoting the health and reproduction of bacteria, fungi, and protozoa, all of which help break down fiber and generate energy for the horse. Recent research in Germany has identified cellobiose as a potential prebiotic for horses.^*

Cellobiose is a disaccharide composed of two glucose molecules formed by the partial hydrolysis of cellulose. Studies in other animals have linked cellobiose to potential prebiotic activity.

In this study, researchers found that cellobiose is successfully broken down by hindgut microbes, boosts beneficial bacteria, and decreases unfavorable bacteria. Most notably, numbers of Clostridia bacteria were increased in horses receiving cellobiose supplementation. Clostridia are a key component in the hindgut microbiome and are more abundant in healthy horses than in those with gastric upset, such as colic. While this research is a solid stepping-off point, further work is needed to confirm the effects of cellobiose as a prebiotic.

The hindgut plays an important role in equine digestion and nutrition. Up to 70% of the horse’s energy comes from fermentation performed by hindgut microbes. Imbalances in the microbial population can lead to health problems.

For horses fed high-grain rations or grazing lush pastures, for example, hindgut acidosis is a risk because the starch and sugar in those meals may not be fully digested before reaching the hindgut. Undigested starch is rapidly fermented in the cecum and colon, causing acidity to increase.

As acidity rises, beneficial hindgut bacteria die, producing endotoxins that, when present in sufficient numbers, can be harmful to gastrointestinal tract (colic) and whole-body health (laminitis). Low-level acidosis can lead to decreased appetite and feed efficiency, stable vices, ulcers, and changes in disposition and performance.

To protect your horse from the harmful effects of acidosis, a pH buffer, such as EquiShure, may be fed to optimize the health of the hindgut. EquiShure is a time-released hindgut buffer, meaning that its encapsulation allows it to travel through the gastrointestinal tract and become activated only when it reaches the hindgut.

As the microbial population of the hindgut changes due to new feeds or lush pastures, using a research-proven product such as EquiShure can help prevent acidosis.

^*Paßlack, N., W. Vahjen, and J. Zentek. 2020. Impact of dietary cellobiose on the fecal microbiota of horses. Journal of Equine Veterinary Science 91:103106.

This article was written by Alex Trauner, a student at the University of Florida and a summer intern at Kentucky Equine Research. Learn more about internship opportunities at Kentucky Equine Research.