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The Importance of Optimal Gut Health

21 lipca 2026 przez
The Importance of Optimal Gut Health
Anouk

A healthy and well-functioning digestive system is essential for the overall health and welfare of the horse. Abrupt changes to the diet can affect both the function and the balance of the digestive system 1,2. Disruption of this balance may result in health disorders that negatively affect the horse's general health and welfare 3.

The equine digestive system can be divided into two functional sections. In the first section, nutrients are primarily digested through enzymatic processes 4. The second section comprises the small intestine, caecum and large intestine. Within these regions, dietary fibre is fermented by the resident microorganisms into the volatile fatty acids butyrate, acetate and propionate 5. Volatile fatty acids provide approximately 60–70% of the energy required for metabolic processes within the horse's body 6. Consequently, the horse's energy supply depends largely on microbial fermentation of dietary fibre within the hindgut 7.








The gastrointestinal tract contains a diverse population of microorganisms, including bacteria, fungi, archaea, protozoa and bacteriophages, each fulfilling specific functions 8. The composition of the gut microbiota influences both volatile fatty acid production and the overall health of the horse 2. This microbial composition is influenced primarily by diet. The fermentation of fibre derived from forage and the subsequent production of volatile fatty acids promote the growth and activity of microorganisms that contribute positively to intestinal function and gut health 9,10.

Abrupt dietary changes or diets containing high levels of sugar and starch can disrupt the balance of the gut microbiota 11. The horse's digestive system has a limited capacity to digest large quantities of starch in the small intestine. When dietary starch intake exceeds this capacity, a proportion of the starch escapes enzymatic digestion and passes into the hindgut, where it undergoes microbial fermentation 12. This alters the activity and efficiency of fibre fermentation 13. Changes in the activity and composition of the gut microbiota can be assessed by measuring faecal pH, lactic acid and volatile fatty acid concentrations 1. Studies have shown that starch fermentation in the hindgut results in increased lactic acid production, leading to a reduction in intestinal pH 11,12. Furthermore, research has demonstrated that this more acidic environment promotes the proliferation of lactic acid-producing bacteria, including species of Streptococcus 11,14. Disturbances in the balance of the gut microbiota, characterised by a reduced pH and increased lactic acid production, have been associated with an increased risk of colic and laminitis in horses 15,16.

Alterations in the gut microbiota may also influence equine behaviour 17,18. Research has shown that changes in the gut microbiota associated with high-starch diets result in increased reactive behaviour 19. In contrast, horses receiving high-fibre diets develop a different microbial composition within the hindgut and generally display calmer behaviour 19.

In summary, a healthy and balanced gut microbiota is essential for maintaining digestive health, overall wellbeing and normal behaviour in horses. It is therefore important to provide a balanced diet that meets the horse's nutritional requirements. In addition, dietary supplements may be used to support gastrointestinal function and help maintain a healthy gut microbiota.

Referenties

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