en تخصصي Special پژوهشي Research <strong>Background: </strong>Heart Failure (HF) has become one of the most prevalent cardiovascular problems worldwide. Considering the beneficial effects of probiotics on human health, we aimed to investigate the anti-inflammatory effect of oral administration of Lactobacillus paracasei in HF induced by isoproterenol.&nbsp;<br> <strong>Methods:</strong> Forty Wistar male rats weighing 80g on average were randomly assigned to five groups of eight each: control, probiotic, HF model, prophylaxis including probiotic + HF, and treatment (HF + probiotic). The rats were treated and examined over 30 days. Heart failure was induced by the subcutaneous injection of isoproterenol (5 mg/kg) once daily for 10 days. At the completion of the study, the ratios of Body, Heart, and Left Ventricle Weights (BW, HW & LVW), serum TNF-&alpha; levels, measured by ELISA, myocardial histopathological lesions were determined and compared among the groups. Cardiac hypertrophy was defined by comparing the LVW to total body weight for each animal.<br> <strong>Results:</strong> The LVW and LVW/HW ratio were significantly increased in the rats with HF (P<0.05). In the treatment group, the LVW/HW and serum TNF-&alpha; level were lower compared to those in the HF group. Also, the infiltration of inflammatory cells, necrosis, and myocardial hypertrophy were remarkably lower than those in the HF group.<br> <strong>Conclusion:</strong> The study findings indicate that the oral administration of Lactobacillus paracasei subsp. paracasei-8700:2 can reduce the cardiac hypertrophy, failure and inflammation induced by the administration of isoproterenol in rats. Therefore, the study results suggest a novel approach for the management and potential prevention of heart failure.<br> &nbsp; Cardiovascular disease, Cytokines, Dysbiosis, Inflammation, Probiotics, Tumor 195 202 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-922-1&slc_lang=en&sid=1 Zohreh Hesari hes.zohreh@gmail.com 100319475328460013317 100319475328460013317 No Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Khatereh Kafshdoozan kafshdouzan@semnan.ac.ir 100319475328460013318 100319475328460013318 Yes Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Parviz Kokhaei p_kokha@yahoo.com 100319475328460013319 100319475328460013319 No Department of Immunology, Cancer Research Center, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran. Bahador Bagheri bahadordvm@yahoo.com 100319475328460013320 100319475328460013320 No Department of Pharmacology, Cancer Research Center, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran. Sahar Ghaffari Khaligh s_ghaffari@semnan.ac.ir 100319475328460013321 100319475328460013321 No Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.