Changes in the faecal microbiota of horses and ponies during a two-year body weight gain programme.
Authors: Langner Katharina, Blaue Dominique, Schedlbauer Carola, Starzonek Janine, Julliand Veronique, Vervuert Ingrid
Journal: PloS one
Summary
# Editorial Summary: Faecal Microbiota Changes During Equine Weight Gain Obesity-related metabolic disorders—particularly insulin dysregulation and laminitis—represent a significant welfare concern in domesticated equids, with ponies disproportionately affected as "easy keepers." Given emerging evidence that intestinal microbiota composition influences obesity development in humans, Langner and colleagues investigated whether similar microbial shifts occur during controlled weight gain in equines. Over two years, ten Shetland ponies and ten warmblood horses received feed at 200% of maintenance energy requirements; faecal samples collected at standardised intervals were analysed using next-generation sequencing to characterise microbial communities and their fermentation products (short-chain fatty acids and lactate). Species-specific responses to overfeeding emerged: whilst microbiota richness decreased in ponies—mirroring patterns documented in obese humans—horses demonstrated a notable reduction in Fibrobacteres (a fibrolytic phylum) alongside increased Actinobacteria. Perhaps most significantly, baseline microbiota composition differed between species, with Fibrobacteres substantially more prevalent in horses than ponies, suggesting intrinsic differences in fibre-degrading capacity. These findings suggest that ponies and horses may have fundamentally different metabolic flexibility during weight gain, with implications for understanding why ponies appear predisposed to metabolic complications; practitioners should consider species-specific nutritional management strategies and recognise that the Fibrobacteres phylum warrants further investigation as a potential marker of metabolic resilience in equine populations.
Read the full abstract on PubMed
Practical Takeaways
- •Ponies and horses respond differently to overfeeding at the microbial level; weight management strategies may need to be species-tailored, particularly for 'easy keeper' ponies
- •Microbiota changes during weight gain may contribute to metabolic complications like insulin dysregulation and laminitis risk; monitor high-risk individuals more closely
- •The relationship between microbiota composition and obesity-related diseases in equines is still emerging—microbiota assessment could become a useful diagnostic tool for metabolic health in the future
Key Findings
- •Faecal microbiota richness decreased in ponies during a 2-year weight gain programme at 200% maintenance energy intake, but remained stable in horses
- •Ponies showed altered Firmicutes phylum composition during weight gain, similar to patterns observed in obese humans
- •Horses demonstrated decreased Fibrobacteres and increased Actinobacteria during weight gain, with Fibrobacteres being more prevalent in horses than ponies at baseline
- •Species-specific microbiota responses to overfeeding exist, with Fibrobacteres identified as a potentially important fibrolytic phylum in equine microbiota that warrants further investigation