The Role of Intestinal Microbial Metabolites in the Immunity of Equine Animals Infected With Horse Botflies.
Authors: Hu Dini, Tang Yujun, Wang Chen, Qi Yingjie, Ente Make, Li Xuefeng, Zhang Dong, Li Kai, Chu Hongjun
Journal: Frontiers in veterinary science
Summary
Intestinal microbiota metabolites represent a largely unexplored mechanism through which horses mount immune responses to parasitic infection, yet their specific role in botfly infestation remained poorly characterised until this 2022 investigation. Researchers employed LC-MS/MS metabolomic analysis and RNA-sequencing on Przewalski's horses with and without *Gasterophilus* infestation to identify faecal microbial metabolites and immunologically relevant gene expression changes in blood, then mapped correlations between these two datasets. Parasite infection substantially altered the metabolite profile, with 31 functionally characterised metabolites showing significant differences; notably, *cathepsin W* (involved in innate and adaptive immunity) was upregulated, whilst *S100-A8* and *S100-A9* genes—which regulate chemokine and cytokine signalling—were downregulated, alongside suppression of Th17 cell differentiation pathways. Purine and pyrimidine metabolism emerged as the primary metabolic routes linking microbial activity to host immune function, controlling nucleotide pools essential for ATP synthesis and RNA production. For practitioners managing parasitised horses, these findings suggest that targeted interventions supporting intestinal microbiota composition may enhance the host's intrinsic immune capacity against botflies, offering a rationale for exploring prebiotics, probiotics, or dietary modifications alongside conventional anthelmintic protocols.
Read the full abstract on PubMed
Practical Takeaways
- •Botfly infections trigger measurable immune and metabolic changes in the horse's gut microbiota that may influence overall health status and recovery
- •Understanding the microbiota-parasite-immunity relationship could inform timing and effectiveness of parasite control programs in equine practice
- •Monitoring microbial metabolite status may eventually provide biomarkers for parasite burden or immune competence, though clinical application is not yet established
Key Findings
- •Botfly parasitic infection alters intestinal microbial metabolite composition across six metabolite categories with 31 metabolites showing significant functional differences
- •Parasite infection upregulates cathepsin W (innate/adaptive immunity) and downregulates S100-A8 and S100-A9 proteins involved in chemokine and cytokine production
- •Purine and pyrimidine metabolism pathways contain the most altered metabolites and differentially expressed genes, affecting ATP/GTP/UTP nucleotide conversion and RNA synthesis
- •Parasitic infection enhances host immune response through microbiota-mediated purine and pyrimidine metabolism pathway alterations