METABOLOMICS
How were these studies conducted?
Samples collected from a number of horses in training of specific ages were analyzed by NMR spectroscopy to work out exactly which metabolites were present. Some of this can be done by computer programs, but unusual metabolites and those unique to the horse were painstakingly identified using clues in their chemical signatures.
What did we learn about the metabolic fingerprint of racehorses?
The urine metabolic profile was remarkably similar between horses. The biggest source of variation was training yard of origin i.e. samples from horses on the same barn were more similar than those from horses on different stables. The major source of this variation was a metabolite called hippurate. Interestingly, this chemical gets its name from the Greek stem “hippos,” meaning “horse,” because it was first identified in horse urine. In humans, hippurate varies with diet, age, and composition of the gut bacterial community. Differences in diet and age profile are inevitable between stables, but the finding raises the intriguing possibility that horses in the same stable also develop similar gut bacterial populations. Metabolic fingerprints from individual horses across a ten-week period were found to be fairly consistent. One horse that received a short course of antibiotics following a racing injury was observed to have a massive shift in its metabolic profile resulting from disturbance of its gut bacteria. This shift was short-lived, with the horse’s normal profile being regained within two weeks of ending its antibiotic treatment. Metabolic profile data from a feeding trial showed how this type of analysis can be used to assess different diets. Characteristic and consistent changes in metabolic fingerprint were detected for horses fed on a traditional racehorse diet or a high-fat diet compared to a grass-only diet.
How will this study benefit racehorse health and welfare?
Metabolomics is still in its infancy but information arising from these HBLBfunded studies provides the essential foundations for future research. One of the most attractive aspects of the metabolomics tool is that samples of urine and feces are relatively easy to collect; understanding of the information that they contain about a horse’s health status is only just beginning. Metabolomic analysis is going to be key to unlocking the secrets of the bacterial communities that live in the gut of the horse. It is these bacteria that have a massive influence on health, performance, and susceptibility to disease. Influencing these bacterial communities through diet, feed supplements, and other methods will be an important means of ensuring racehorse health in the future. n
Top: A typical NMR spectrogram of equine urine, each numbered peak representing a unique metabolite. With this technique, the position of each peak depends upon its chemical composition and the height of each peak corresponding to the amount. Precise measurements of the position and height of each peak are used to identify and quantify the metabolites detected Above: Metabolomics may provide invaluable insight on racehorse health – with the clues contained in urine and feces
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