Sequential Modulation of the Equine Fecal Microbiota and Fibrolytic Capacity Following Two Consecutive Abrupt Dietary Changes and Bacterial Supplementation.
Authors: Collinet Axelle, Grimm Pauline, Julliand Samy, Julliand Véronique
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary The equine hindgut microbiota undergoes significant disruption when horses are switched abruptly from high-fibre to high-starch diets, but the timeline and extent of recovery—and whether bacterial supplementation aids this process—remained poorly characterised until now. Collinet and colleagues monitored fecal microbiota composition and function in twelve horses across two consecutive dietary shifts: a 2-week high-fibre baseline, 5 days on high-starch feed, then 7 weeks back to high-fibre, with six animals receiving lactic acid bacteria supplementation throughout. Within 2 days of high-starch exposure, fibrolytic bacterial populations declined whilst amylolytic capacity increased; critically, fecal parameters required 3–4 weeks to return to baseline after resuming the high-fibre diet, with a notable bloom in cellulolytic bacteria and pH reduction evident at 1.5 weeks post-return. Supplemented horses showed enhanced relative abundance of fibrolytic genera at key recovery points (2 days post-starch challenge and 2–3 weeks after high-fibre reintroduction), suggesting that targeted bacterial supplementation may accelerate microbial stabilisation. These findings validate fecal analysis as a practical non-invasive monitoring tool for practitioners managing dietary transitions, particularly in clinical cases where hindgut dysbiosis risk is elevated, and indicate that recovery from acute dietary insult extends considerably beyond the widely assumed 2–3 week window.
Read the full abstract on PubMed
Practical Takeaways
- •Fecal microbiota analysis can effectively monitor hindgut microbial responses to dietary changes, providing a non-invasive alternative to cecal/colonic sampling
- •Plan at least 3-4 weeks for complete microbiota recovery after abrupt dietary transitions; rushing dietary changes risks prolonged dysbiosis and reduced digestive efficiency
- •Probiotic supplementation with lactic acid bacteria may accelerate restoration of fibrolytic capacity during dietary transitions, potentially reducing colic and digestive disturbance risk
Key Findings
- •Abrupt high-fiber to high-starch dietary change caused decreased fibrolytic activity and increased amylolytic activity within 2 days, mimicking previously documented cecal and colonic changes
- •Fecal microbiota parameters required 3-4 weeks to stabilize at basal levels after returning to high-fiber diet
- •Cellulolytic bacterial bloom with lower pH occurred 1.5 weeks after return to high-fiber diet, indicating enhanced fiber degradation recovery
- •Lactic acid bacteria supplementation enhanced relative abundance of potentially fibrolytic genera at 2 days post-starch challenge and 2-3 weeks after return to forage diet