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

Abstract

The attention of sports community toward probiotic supplementation as a way to promote exercise and training performance, together with good health, has increased in recent years. This has applied also to horses, with promising results. Here, for the first time, we tested a probiotic mix of several strains of live bacteria typically employed for humans to improve the training performance of Standardbred horses in athletic activity. To evaluate its effects on the horse performance, we measured lactate concentration in blood, a translational outcome largely employed for the purpose, combined with the study of hematological and biochemical parameters, together with urine from a metabolomics perspective. The results showed that the probiotic supplementation significantly reduced postexercise blood lactate concentration. The hematological and biochemical parameters, together with urine molecular profile, suggested that a likely mechanism underlying this positive effect was 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 that such switch was linked to sulfur metabolism. NEW & NOTEWORTHY Probiotic supplementation could reduce postexercise blood lactate concentration in Standardbred horses in athletic activity. Blood parameters, together with urine molecular profile, suggest the mechanism underlying this positive effect is connected to a switch of energy source in muscle from carbohydrates to short-chain fatty acids. Sulfur-containing molecules found in urines in connection to probiotics administration suggested that such switch was linked to sulfur metabolism.

Keywords: Standardbred horse; exercise; lactate; probiotics; urine metabolomics.

Fig. 1.

Schedule of the clinical trials activity. T0, before treatment. T1, after treatment.

Fig. 2.

Blood lactate concentration in horses before (T0) or after (T1) treatment with probiotics (Prob) and placebo (Pbo), and pre- and posttraining. Samples obtained at T0 and after treatment with placebo were considered as constituting a single group (white boxplots). Samples obtained after treatment with probiotics (gray boxplots) were compared with them by nonparametric univariate analysis test (P values).

Fig. 3.

Significant correlations (P < 0.05) with lactate concentration registered postexercise of the hematological or biochemical parameters and the molecules listed in Tables 2, 3, and 4. MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDWc, red cells distribution width coefficient.