Functional parameters and degree of myocardial damage by ischemia-reperfusion model of isolated heart were investigated during acute experiments on rats with an antibiotic-induced intestinal dysbiosis after administration of the probiotic strains of Enterococcus faecium L3. Administration of antimicrobial drugs has resulted in an increased heart rate and in an increase in coronary flow of isolated heart. Administration of enterococci after the global ischemia has caused rats to have a decrease in diastolic pressure, increased systolic and pulse pressure, and an increased intensity of coronary flow. The article presents data on changes in the composition of the intestinal microbiota and the immune system that was previously obtained in studies based on this experimental model.