Comparison of the fecal microbiota with high- and low performance race horses

Taemook Park1, Jungho Yoon1, YoungMin Yun2, Tatsuya Unno3,*
Author Information & Copyright
1Equine Clinic, Jeju Racecourse, Korea Racing Authority, Jeju 63066, Korea.
2College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea.
3Department of Biological Sciences and Biotechnology, Chungbuk National University, Cheongju 28644, Korea.
*Corresponding Author: Tatsuya Unno, Department of Biological Sciences and Biotechnology, Chungbuk National University, Cheongju 28644, Korea, Republic of. Phone: +82-64-754-3354. E-mail:

© Copyright 2023 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Exercise plays an important role in regulating energy homeostasis, which affects the diversity of the intestinal microbial community in humans and animals. To the best of the authors’ knowledge, few studies have reported the associations between horse gut microbiota along with their predicted metabolic activities and the athletic ability of Jeju horses and Thoroughbreds living in Korea. This study was conducted to investigate the association between the gut microbiota and athletic performance in horses. This study sequenced the V3 and V4 hypervariable regions of the partial 16S rRNA genes obtained from racehorse fecal samples and compared the fecal microbiota between high- and low-performance Jeju horses and Thoroughbreds. Forty-nine fecal samples were divided into four groups: high-performance Jeju horses (HJ, n = 13), low-performance Jeju horses (LJ, n = 17), high-performance Thoroughbreds (HT, n = 9), and low-performance Thoroughbreds (LT, n = 10). The high-performance horse groups had a higher diversity of the bacterial community than the low-performance horse groups. Two common functional metabolic activities of the hindgut microbiota (i.e., tryptophan and succinate syntheses) were observed between the low-performance horse groups, indicating dysbiosis of gut microbiota and fatigue from exercise. On the other hand, high-performance horse groups showed enriched production of polyamines, butyrate, and vitamin K. The racing performance may be associated with the composition of the intestinal microbiota of Jeju horses and Thoroughbreds in Korea.

Keywords: Fecal microbiota; Jeju horse; NGS; Racing performance; Thoroughbred