[Impact of nutrition and probiotics on the equine microbiota: current scientific knowledge and legal regulations].

The study investigates the impact of diet and probiotics on the gut microbiota of horses, noting that certain diets can significantly influence the growth of different types of bacteria. It also examines the ambiguity surrounding the effects of Saccharomyces cerevisiae yeast strains as probiotics in adult horses, currently the only officially registered probiotics for horses in the EU.

Dietary Influence on the Equine Microbiota

• The research notes that the hindgut microbiota in horses, a diverse bacterial community, can be greatly impacted by the diet given to the animal.
• For instance, a diet rich in starch encourages the proliferation of certain bacteria, especially those capable of breaking down starch into lactate.
• Meanwhile, the same diet decreases the growth of cellulolytic bacteria, which are crucial for fiber digestion.

Probiotic Intervention

• The study discusses the use of probiotics as a strategy to achieve a balanced gut microbiota and mitigate the adverse effects of a starch-rich diet in horses.
• It mentions Saccharomyces cerevisiae yeast strains as the only officially registered probiotics for horses in the European Union.

Limited Evidence of Probiotic Impact in Horses

• Interestingly, despite the widespread use of Saccharomyces cerevisiae yeast strains, research into their effects on adult horses has reportedly been inconclusive.
• The study calls attention to the need for further investigation into the efficacy of yeast-based probiotics in regulating horse gut microbiota.