The Fecal Bacterial Microbiota in Horses with Equine Recurrent Uveitis.
Authors: Martin de Bustamante Michelle, Gomez Diego, MacNicol Jennifer, Hamor Ralph, Plummer Caryn
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Fecal Bacterial Microbiota in Equine Recurrent Uveitis Equine recurrent uveitis (ERU) remains a significant cause of blindness in horses, yet its aetiology is incompletely understood; this study investigated whether dysbiosis of the faecal microbiota might contribute to disease pathogenesis by comparing bacterial communities in 15 ERU-affected horses with 15 matched healthy controls using 16S rRNA gene sequencing. Both groups demonstrated similar microbial composition dominated by Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria (accounting for >60% of sequences), with no significantly enriched taxa in either population and no differences in alpha or beta diversity indices (p >0.05). The findings suggest that ERU is not associated with dysbiosis of the gastrointestinal microbiota, implying that microbiota-mediated mechanisms are unlikely to be primary drivers of disease in this cohort. Whilst this does not exclude the possibility that local mucosal immune dysregulation or systemic immune responses contribute to ERU pathogenesis, practitioners should consider that ERU-affected horses do not require microbiota-targeted interventions (such as probiotic therapy or dietary prebiotic supplementation) based on microbial compositional changes alone. However, larger multi-centre studies with longitudinal sampling and assessment of metabolic end-products (short-chain fatty acids) rather than taxonomy alone would strengthen our understanding of whether subtle functional dysbiosis exists independent of compositional changes.
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Practical Takeaways
- •ERU is not linked to dysbiosis or changes in the fecal microbiota, suggesting gut bacterial composition is unlikely to be a causative or contributory factor in this condition
- •Microbiota-modulating interventions (probiotics, prebiotics) are not supported by this evidence as a treatment strategy for ERU
- •Investigation into other mechanisms of ERU pathogenesis should be prioritized over microbiota-based approaches
Key Findings
- •Fecal bacterial microbiota composition was similar between horses with ERU and healthy controls, with Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominating in both groups (>60% of sequences)
- •No taxa were significantly enriched in ERU horses compared to controls based on linear discriminant analysis effect size (LEfSe)
- •Alpha and beta diversity indices showed no significant differences between ERU and control groups (p > 0.05 for all tests)
- •Equine recurrent uveitis is not associated with alterations of the gastrointestinal bacterial microbiota