Fecal microbiota in horses with asthma.
Authors: Leclere Mathilde, Costa Marcio C
Journal: Journal of veterinary internal medicine
Summary
# Fecal Microbiota in Horses with Asthma Leclere and Costa's 2020 investigation addresses a significant gap in equine medicine by characterising the faecal microbiota of asthmatic horses, recognising that the gastrointestinal microbiota may both reflect and modulate systemic inflammatory responses relevant to airway disease. Using 16S rRNA gene sequencing, the researchers collected faecal samples from six asthmatic and six healthy horses across three distinct conditions—pasture grazing, indoor housing with quality hay, and indoor housing with poor-quality (dusty) hay—to capture microbiota changes during both remission and exacerbation phases. The key finding was differential microbial adaptation: whilst healthy horses mounted a predictable increase in *Fibrobacter* abundance when eating hay (an expected fibre-fermenting response), asthmatic horses failed to demonstrate this adaptive shift, instead showing greater volatility in low-abundance bacterial populations when exposed to environmental and dietary triggers. This dysbiotic pattern suggests that asthmatic horses lack the microbiotic resilience of healthy individuals and raises the possibility of bidirectional communication between airway inflammation and gut dysbiosis. For practitioners, these findings warrant investigation into whether targeted dietary management, prebiotic/probiotic interventions, or dust minimisation protocols might restore microbiota stability and potentially ameliorate asthma severity, though further mechanistic research is needed to establish causation and inform evidence-based therapeutic strategies.
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Practical Takeaways
- •Dietary management alone may be insufficient to restore normal microbiota function in asthmatic horses; microbiota-targeted interventions warrant investigation
- •Environmental factors (pasture vs. indoor housing) and hay quality significantly alter fecal microbiota, suggesting integrated management strategies may benefit asthmatic horses
- •Dysbiotic microbiota in asthmatic horses may perpetuate systemic inflammation; monitoring and modulating gut health could become adjunctive therapeutic targets for managing equine asthma
Key Findings
- •Fecal microbiota of asthmatic horses shows reduced adaptability to environmental and dietary changes compared to healthy horses
- •Low-abundance bacteria in asthmatic horses are significantly affected during exacerbations, with altered membership and LEfSe analysis results
- •Fibrobacter abundance increased significantly in healthy horses consuming hay but this adaptive response was absent in asthmatic horses
- •Asthmatic horses demonstrate dysbiotic microbiota patterns that do not normalize with dietary improvements (good quality hay vs. dusty hay)