Homeostasis of the Intestinal Mucosa in Healthy Horses-Correlation between the Fecal Microbiome, Secretory Immunoglobulin A and Fecal Egg Count.
Authors: Żak-Bochenek Agnieszka, Bajzert Joanna, Sambor Dominika, Siwińska Natalia, Szponar Bogumiła, Łaczmański Łukasz, Żebrowska Paulina, Czajkowska Aleksandra, Karczewski Maciej, Chełmońska-Soyta Anna
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary The intestinal mucosa's capacity to mount an effective immune defence relies on two interdependent systems: local antibody production and a healthy microbial community. Researchers in this 2022 study examined faecal samples from clinically healthy horses using high-throughput 16S rRNA gene sequencing and ELISA immunoassays to characterise relationships between microbial diversity, secretory immunoglobulin A (SIgA) levels, and gastrointestinal nematode burden. Phylogenetic diversity of the microbiome showed significant positive correlations with SIgA concentration (r = 0.61, p = 0.0354), and notably, horses with greater microbial diversity also harboured higher Cyathostomum egg counts (r = 0.79, p = 0.0023), suggesting that the immune system may be responding to parasite presence rather than eliminating it entirely. Specific bacterial taxa—particularly Proteobacteria and Ruminococcus flavefaciens—were independently associated with elevated faecal SIgA, indicating that certain microbiome members may prime the mucosal immune response. These findings underline the complexity of intestinal homeostasis in horses and suggest that managing parasite burden, optimising microbial composition, and supporting mucosal immunity are interconnected priorities rather than isolated concerns.
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Practical Takeaways
- •Maintaining diverse, healthy fecal microbiota appears linked to stronger mucosal immunity (higher SIgA) in horses—consider management practices that support microbial diversity when addressing parasite control
- •The presence of small strongyles (Cyathostomum) correlates with microbiome changes; routine fecal egg monitoring alongside parasite management may help preserve beneficial gut bacteria and immune function
- •Specific bacterial taxa (Proteobacteria, Ruminococcus flavefaciens) associated with better mucosal immunity suggest that probiotic or prebiotic strategies targeting these groups could be worth investigating in clinical practice
Key Findings
- •Phylogenetic diversity of the fecal microbiome positively correlated with secretory IgA levels (r=0.61, p=0.0354)
- •Proteobacteria phylum and Ruminococcus flavefaciens species were positively associated with fecal SIgA (p<0.05)
- •Microbiome diversity showed strong positive correlation with Cyathostomum egg count (r=0.79, p=0.0023)
- •Firmicutes dominated the fecal microbiota, followed by Bacteroidota, Verrucomicrobiota, and Fibrobacterota