Gut feelings: Study suggests racehorse poop might help predict future winners

Studies show that diverse gut bacteria in Thoroughbred foals predict better athletic performance and health. (Image: Canva)

A study from the University of Surrey has uncovered a surprising link between the gut bacteria of Thoroughbred foals and their future racing prowess and health. It turns out that the microbial diversity in a foal’s gut at just one month old can offer clues about their future performance on the racetrack and their overall wellbeing.

Foals' Gut Microbes: A Window into Future Performance
The research, conducted by Surrey’s School of Veterinary Medicine and School of Biosciences, took a deep dive into the gut health of 52 foals. By analysing 438 fecal samples, the team tracked the foals' health issues and their racing achievements from birth up to the age of three. Their findings reveal a clear pattern: foals with richer gut microbiomes tended to perform better in races and faced fewer health complications.

Professor Chris Proudman, who led the study, stressed the importance of gut health for racehorses. “For racehorses, preventing illness and injury is crucial, but so is maximising their performance potential. Our findings show that the health of a foal’s gut bacteria from an early age can have a lasting impact,” he said.

Antibiotics: A Double-Edged Sword
The study also highlighted the downsides of early antibiotic use. Foals that received antibiotics within their first month had lower bacterial diversity and, consequently, poorer race results and a higher likelihood of respiratory diseases later in life.  Professor Roberto La Ragione, co-investigator at the School of Biosciences, explained, “While antibiotics are crucial for treating infections and safeguarding foal health, their use must be managed carefully. Our study shows that antibiotics can disrupt the gut microbiome with long-lasting effects on health and performance.” The next phase of the research will focus on strategies to minimise this disruption while still effectively treating infections.

Future Directions and Innovations
The study also uncovered a link between low gut bacterial diversity in early life and an increased risk of developing soft tissue and orthopedic problems later on. Researchers suspect that this may be related to how the immune system is primed early in life. The exact reasons for the negative impacts on racehorse performance are still being investigated.

Dr. Kirsten Rausing, Chairman of the International Thoroughbred Breeders Federation and a sponsor of the study through her ALBORADA Trust, praised the research: “This groundbreaking study highlights the critical role of gut health in foals. By improving our understanding and management of gut bacteria, we can raise healthier foals who are more likely to succeed as racehorses.”

Ongoing work aims to develop new probiotics to enhance foal gut health and to refine antibiotic use to preserve gut microbiome balance.