In vitro simulation of the equine hindgut as a tool to study the influence of phytosterol consumption on the excretion of anabolic-androgenic steroids in horses.

This study focuses on the faux excretion of synthetic anabolic steroids in horses. Researchers used an in-vitro simulation of the horse’s hindgut to study the possible digestive transformation of steroidal precursors derived from their feed, called phytosterols.

Objective of the Study

The research aims to examine whether phytosterols – plant-based sterols found in horse feed – could be transformed into anabolic-androgenic steroids in the horse’s gut and thus be excreted in the urine.

Methodology

• They created an in-vitro model of the horse’s hindgut, with fecal matter taken from eight different horses. This model allowed them to study the transformation processes that could happen during digestion.
• They monitored short-chain fatty acid formation and consumption of amino acids and carbohydrates throughout digestion, to ensure that the simulation accurately represented the horse’s hindgut.
• They added β-Bol, a known metabolic product of testosterone, to the model. This compound is frequently detected in horse urine. They found that upon addition, it turned into either ADD or αT – both of which are anabolic-androgenic steroids.
• The researchers also added ADD to the model, and found that it turned into β-Bol. This transformation was observed for all eight horse specimens, and was dependent on the specific horse.

Results and Conclusion

• The researchers found no evidence of phytosterols transforming into detectable β-Bol levels in the hindgut simulation. They only saw low concentrations of AED, another testosterone precursor, post-consumption of phytosterols.
• The results of the study confirm that ADD can be transformed into β-Bol during digestion, and phytosterols can be transformed into small amounts of AED.
• Nonetheless, the study did not find a direct link connecting the ingestion of phytosterols and the detection of β-Bol, suggesting that consumption of phytosterols is not directly accountable for the presence of anabolic-androgenic steroids in horse urine.