Luminal and Mucosal Microbiota of the Cecum and Large Colon of Healthy and Diarrheic Horses.
Authors: Arroyo Luis G, Rossi Laura, Santos Bruna P, Gomez Diego E, Surette Michael G, Costa Marcio C
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Understanding the microbial ecology of equine colitis requires distinguishing between the bacteria living within the intestinal lumen and those adhering to the mucosal layer, a distinction this 2020 study systematically explored by analysing samples from both environments in healthy and diarrheic horses. The researchers identified marked differences in microbial richness and community composition between luminal and mucosal populations in affected animals, revealing that dysbiosis in colitis operates across multiple compartments of the cecum and large colon rather than affecting the microbiota uniformly. Key pathogenic or dysbiosis-associated taxa—notably *Escherichia*, *Fusobacterium*, and *Lactobacillus*—showed altered abundance patterns that differed between the mucosa and luminal contents, suggesting that sampling methodology may significantly influence which microbial shifts clinicians actually detect. For practitioners, these findings emphasise that single-site or single-compartment sampling protocols may misrepresent the full microbial picture in diarrheic cases, and highlight the need for further research to establish whether specific mucosal or luminal microbial signatures could serve as reliable diagnostic markers or treatment targets in equine colitis management.
Read the full abstract on PubMed
Practical Takeaways
- •Diarrhea in horses involves dysbiosis affecting both the mucus layer and intestinal lumen differently—sampling location matters for diagnostic microbiota analysis
- •Monitoring changes in Escherichia, Fusobacterium, and Lactobacillus populations may help identify colitis cases earlier and guide targeted probiotic or antimicrobial interventions
- •Understanding mucosal versus luminal microbiota differences could improve treatment strategies by allowing practitioners to target specific microbial niches in the cecum and colon
Key Findings
- •Marked differences in microbial richness and community composition exist between mucosal and luminal microbiota in the cecum and colon of diarrheic horses compared to healthy horses
- •Microbial dysbiosis in horses with colitis occurs at different levels of the intestinal tract with distinct microbiota composition between mucosa and luminal content
- •Key taxa including Escherichia, Fusobacterium, and Lactobacillus show dysbiosis-associated changes in equine intestinal microbiota and warrant further investigation for diagnostic and therapeutic applications