Field study examining the mucosal microbiome in equine glandular gastric disease.
Authors: Paul Linda J, Ericsson Aaron C, Andrews Frank M, McAdams Zachary, Keowen Michael L, St Blanc Michael P, Banse Heidi E
Journal: PloS one
Summary
Equine glandular gastric disease (EGGD) represents a significant performance limitation in athletic horses, yet its underlying pathophysiology remains incompletely understood; this field-based investigation extended previous laboratory findings by examining whether gastric mucosal microbiome differences associated with EGGD persist across diverse barn environments and management regimens. Using endoscopic biopsies from three sample sites—normal pyloric tissue in healthy horses (controls), normal-appearing pyloric tissue in EGGD-affected horses, and disrupted glandular lesions in EGGD cases—researchers conducted 16S ribosomal RNA gene sequencing to characterise microbial community composition and performed multivariate analysis of diet and management factors. Lesion biopsies exhibited distinctly altered microbial communities compared to control biopsies, characterised by reduced Actinomycetota abundance and enrichment of Lactobacillus and Actinobacillus genera; conversely, control biopsies showed higher representation of Staphylococcus, Lawsonella and Streptococcus salivarius species. The risk factor analysis identified increased weekly exercise duration as a significant predictor of EGGD development, suggesting that training intensity warrants consideration alongside microbial dysbiosis in disease aetiology. These findings have practical implications for practitioners: the identified microbial signatures may eventually support diagnostic approaches or guide targeted interventions, whilst the exercise-associated risk factor reinforces the importance of conditioning programmes tailored to individual tolerance and systematic acid-reducing protocols in high-intensity training regimens.
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Practical Takeaways
- •EGGD involves distinct changes in gastric mucosal bacterial populations that may inform future diagnostic or therapeutic approaches targeting specific microbial dysbiosis
- •High-intensity training schedules should be monitored and managed carefully, as increased weekly exercise duration is associated with greater EGGD risk—consider periodising workload and recovery
- •Understanding that EGGD is linked to microbiome alterations opens potential management strategies beyond just acid suppression, though clinical applications of microbiome data remain to be established
Key Findings
- •Lesion biopsies from EGGD-affected horses showed significantly different microbial community structure compared to control biopsies, with reduced Actinomycetota phylum abundance
- •EGGD lesion sites were enriched in Lactobacillus and Actinobacillus genera, while healthy pyloric mucosa showed enrichment of Staphylococcus, Lawsonella, and Streptococcus salivarius
- •Exercise duration per week was identified as a significant risk factor for development of EGGD in athletic horses