Cardioprotective Effect of Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis Is Mediated by Sarcolemmal but Not Mitochondrial ATP-Sensitive Potassium Channels in Rats with Systemic Inflammation

In this study, we investigated the role of mitochondrial and sarcolemmal ATP-sensitive potassium channels (mKATP and sKATP, respectively) in the mechanisms of cardioprotection afforded by a combination of <i>Lactobacillus acidophilus</i> (LA-5) and <i>Bifidobacterium animalis</i> subsp. <i>lactis</i> (BB-12) in rats with systemic inflammatory response (SIR), which included diet-induced obesity and chemically induced colitis. Selective mKATP and sKATP blockers were used for assessment of their involvement in the mechanisms of probiotic preconditioning, while myocardial tolerance to ischemia-reperfusion injury was determined in the isolated perfused heart subjected to global ischemia-reperfusion. Intragastric administration of lyophilized LA-5 and BB-12 at a dose of 1.2 × 10⁸ CFU/mL for 7 days resulted in myocardial infarct size reduction. This cardioprotective effect was associated with specific changes in cytokine concentrations, namely, reduced levels of interleukin-1β, tumor necrosis factor-α, and interferon-γ. Moreover, probiotic therapy reversed SIR-induced reduction in the abundance of <i>Lactobacillus</i> spp. in the gut and SIR-induced elevation of acetic and propionic short-chain fatty acids in the blood. Preischemic pharmacological inhibition of sKATP channels but not mKATP channels abolished cardioprotective effect of probiotics. Therefore, it was suggested that sKATP channels are implicated in myocardial protection elicited by probiotics.