Introduction: This study aimed to investigate the effects of aerobic interval training (AIT) and probiotic supplementation, both individually and in combination, on the expression of genes associated with the extrinsic apoptotic pathway, including the Fas/FasL axis, TNF-α, Caspase-8, and Caspase-3, in the cardiac tissue of rats with myocardial infarction.

Methods: In this experimental laboratory study, 48 male Wistar rats were divided into six groups: healthy control, sham, myocardial infarction (MI), MI + training, MI + probiotic supplementation, and MI + training + probiotic supplementation. The myocardial infarction model was induced through coronary artery ligation. The aerobic interval training protocol was performed for 10 weeks, and probiotic supplementation was administered daily. Gene expression levels were assessed using the Real-Time PCR technique and the 2^-ΔΔCt method, and data were analyzed using analysis of variance (ANOVA).

Results: The results demonstrated that the induction of myocardial infarction significantly increased the expression of genes related to the Fas/FasL axis, TNF-α, Caspase-8, and Caspase-3 in cardiac tissue. In contrast, both aerobic interval training and probiotic supplementation individually reduced the expression levels of these apoptotic markers. However, the combined intervention resulted in a greater reduction in the expression of the investigated genes compared with either intervention alone. Moreover, TNF-α, as an inflammatory marker, showed decreased expression in the intervention groups (p ≤ 0.05).

Conclusion: Overall, the findings of this study indicate that aerobic interval training combined with probiotic supplementation may contribute to improving the molecular status of cardiac tissue following myocardial infarction by modulating the expression of Fas/FasL axis genes and other genes involved in the extrinsic apoptotic pathway, as well as partially reducing inflammatory responses.