Microbial Community Shifts in the Gut of Jeju Horses with Digestive Problems: A Case-Control Study of Fecal Microbiota
Jay In Park
St. Johnsbury Academy Jeju, Jeju, South Korea
Publication date: November 20, 2025
St. Johnsbury Academy Jeju, Jeju, South Korea
Publication date: November 20, 2025
DOI: http://doi.org/10.34614/JIYRC2025II12
ABSTRACT
The gut microbiota plays a vital role in equine gastrointestinal health, but limited data exist on the microbial alterations associated with digestive disorders in Jeju horses. This study aimed to compare the fecal microbiome composition between healthy Jeju horses and those with recurrent digestive problems using 16S rRNA gene sequencing. A total of 20 horses, all imported from Argentina and housed under controlled conditions in Jeju, were divided into healthy (n=10) and digestive-issue (n=10) groups based on clinical history. Fecal samples were collected, and microbial DNA was extracted, amplified (V3–V4 region), and sequenced on the Illumina MiSeq platform. Bioinformatics analysis via QIIME2 revealed that horses with digestive issues had significantly reduced microbial diversity and richness. Notable shifts included decreased Firmicutes and increased Bacteroidetes, Proteobacteria, and potential pathogens such as Fusobacterium and Streptococcus. NMDS ordination confirmed a clear compositional separation between the two groups. These findings are consistent with microbial dysbiosis reported in other equine gastrointestinal studies and suggest that specific microbial patterns may serve as biomarkers of digestive dysfunction. This study offers new insights into the gut microbial ecology of Jeju horses and provides a basis for future longitudinal and functional microbiome studies targeting equine health.
The gut microbiota plays a vital role in equine gastrointestinal health, but limited data exist on the microbial alterations associated with digestive disorders in Jeju horses. This study aimed to compare the fecal microbiome composition between healthy Jeju horses and those with recurrent digestive problems using 16S rRNA gene sequencing. A total of 20 horses, all imported from Argentina and housed under controlled conditions in Jeju, were divided into healthy (n=10) and digestive-issue (n=10) groups based on clinical history. Fecal samples were collected, and microbial DNA was extracted, amplified (V3–V4 region), and sequenced on the Illumina MiSeq platform. Bioinformatics analysis via QIIME2 revealed that horses with digestive issues had significantly reduced microbial diversity and richness. Notable shifts included decreased Firmicutes and increased Bacteroidetes, Proteobacteria, and potential pathogens such as Fusobacterium and Streptococcus. NMDS ordination confirmed a clear compositional separation between the two groups. These findings are consistent with microbial dysbiosis reported in other equine gastrointestinal studies and suggest that specific microbial patterns may serve as biomarkers of digestive dysfunction. This study offers new insights into the gut microbial ecology of Jeju horses and provides a basis for future longitudinal and functional microbiome studies targeting equine health.
