A Multiomic Approach to Investigate the Effects of a Weight Loss Program on the Intestinal Health of Overweight Horses.
Authors: Walshe Nicola, Cabrera-Rubio Raul, Collins Roisin, Puggioni Antonella, Gath Vivian, Crispie Fiona, Cotter Paul D, Brennan Lorraine, Mulcahy Grace, Duggan Vivienne
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Obesity in horses is increasingly recognised as a significant welfare and health concern, yet evidence regarding safe, effective weight loss protocols and their effects on gastrointestinal health remains limited. Walshe and colleagues conducted a randomised controlled trial over six weeks with 14 overweight sedentary horses and ponies, comparing a restricted diet (1.4% body weight dry matter intake) combined with structured exercise against a maintenance diet with moderate exercise, whilst employing a comprehensive multiomic approach including clinical morphometry, ultrasound assessment, blood pressure monitoring, 16S rRNA microbiota profiling, and faecal metabolome analysis via NMR spectroscopy. The treatment group achieved significant weight loss and waist circumference reduction (both p <0.00001 and p <0.0001 respectively), with improved alpha-diversity of the faecal microbiota by study end (p <0.05), whilst both groups demonstrated measurably lower resting blood pressure regardless of intervention. Importantly, whilst metabolomic changes occurred in both groups over the study period, no significant between-group differences emerged in microbiota composition or metabolic profiles at any sampling point, suggesting that the intestinal ecological environment may be relatively resilient to short-term dietary restriction and exercise in healthy overweight horses—a reassuring finding for practitioners implementing weight management programmes. These results support the safety and efficacy of moderate caloric restriction with structured exercise for equine weight loss, though longer-term studies would help clarify whether microbiota-targeted interventions offer additional clinical benefits beyond conventional weight reduction strategies.
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Practical Takeaways
- •A structured weight loss program combining diet restriction to 1.4% body weight and prescribed exercise is effective and safe for overweight horses, achieving measurable weight loss without adverse outcomes.
- •Weight loss improves intestinal microbial diversity and overall intestinal health markers, which may have long-term benefits for metabolic health and disease prevention in obese horses.
- •Even the control group (maintenance diet with foraging-mimic exercise) showed improved blood pressure and metabolomic changes, suggesting that any increase in appropriate activity level benefits equine cardiovascular health.
Key Findings
- •Treatment group achieved significant weight loss (p < 0.00001) and reduced waist circumference (p < 0.0001) compared to controls over 6 weeks with diet restriction (1.4% BW) and prescribed exercise.
- •Fecal microbiota alpha-diversity significantly increased in the treatment group from start to end of study (p < 0.05), indicating improved intestinal microbial diversity with weight loss.
- •Significant metabolomic changes occurred in both groups between start and end of study (p < 0.05), suggesting weight loss program alters fecal metabolites independent of group allocation.
- •Resting blood pressure decreased significantly in all horses by end of study, indicating cardiovascular benefit of the weight loss intervention.