Probiotic supplementation in trained trotter horses: effect on blood clinical pathology data and urine metabolomic assessed in field

The use of probiotics for promoting athletic performance has gained popularity in recent years. This study investigated the effects of probiotics on athletic performance of Standardbred horses. The probiotic blend Slab51 (Sivomixx®) was administrated PO for 21 days. Blood lactate, hematological and biochemical parameters, and metabolomic analysis of urine were assessed. Probiotic supplementation significantly reduced post-exercise blood lactate in horses. Previous studies demonstrated that lactic acid bacteria can get energy from arginine deamination to citrulline, citrulline cleavage to ornithine plus carbamoyl phosphate converted into ATP and carbon dioxide, generating two moles of ammonia useful to compensate the acidity generated by lactic acid. Hematochemical parameters and urine molecular profile, suggested a positive effect on the performance connected to a switch of energy source in muscle from carbohydrates to short-chain fatty acids. Three sulfur-containing molecules differently concentrated in urines in connection to probiotics administration suggested a switch linked to sulfur metabolism.