Background and Objective: There are evidences for the beneficial effects of probiotic products on non-alcoholic fatty liver disease (NAFLD). The aim of the current study was to investigate the effects of probiotic yogurt consumption compared to conventional yogurt on enzymes and ecogenisity of liver in patients with NAFLD. Materials and Methods: This study was conducted on 72 patients with NAFLD. Subjects were randomly allocated to either the intervention or control group (n=36, in each group) and consumed 300 g of probiotic yogurt or 300 g of conventional yogurt everyday for 8 weeks, respectively. Dietary intakes, anthropometric parameters, liver ultrasonography, serum levels of liver enzymes were measured at the beginning and the end of the study. Statistical analysis was performed using SPSS software and chi-square test, independent sample t-tests, analysis of covariance and paired t-tests. Results: There were not any significant differences in baseline characteristics at the beginning of the study. Probiotic yogurt consumption caused 13.6% decrease in Alanine Amino Transferase (ALT) compared with the control group and reduced Aspartate Amino Transferase (AST) by 13.87% (P <0.02 and P <0.005, respectively). No significant changes were seen in AST to ALT ratio between the groups after the trial (P-value >0.05). Results of liver ultrasonography showed significant improvement in intervention group versus control group (P-value <0.02). Conclusion: Probiotic yogurt consumption lowered serum ALT and AST concentrations in our subjects and improved liver ecogenisity. Nevertheless, it might have a role in the improvment of NAFLD. 1- Dowman JK, Tomlinson JW, Newsome PN. Pathogenesis of non-alcoholic fatty liver disease. Q J Med. 2010 103: 71-83. 2- Kelishadi R, Poursafa P. Obesity and air pollution: global risk factors for pediatric non-alcoholic fatty liver disease. Hepat Mon. 2011 11: 794-802. 3- Amarapurkar DN, Hashimoto E, Lesmana LA, Sollano JD, Chen PJ, Goh KL. How common is non-alcoholic fatty liver disease in the Asia-Pacific region and are there local differences? J Gastroenterol Hepatol. 2007 22: 788-93. 4- Adibi A, Hekmatnia A, Shayganfar S. Ultrasound screening of nonalcoholic fatty liver in isfahan medical university personnel. Iranian Journal of Radiology. 2008 5: 1-1. 5- Ballestri S, Lonardo A, Bonapace S, Byrne CD, Loria P, Targher G. Risk of cardiovascular, cardiac and arrhythmic complications in patients with non-alcoholic fatty liver disease. World J Gastroenterol. 2014 20: 1724-45. 6- Lam B, Younossi ZM. Review: treatment options for nonalcoholic fatty liver disease. Therapeutic Advances in Gastroenterology. 2010 3: 121-37. 7- Eslami L, Merat S, Nasseri-Moghaddam S. Treatment of non-alcoholic fatty liver disease (NAFLD): a systematic review. Middle East J of Dig Diseases (MEJDD). 2009 1: 89-99. 8- Halegoua-De Marzio D, Fenkel J. Concepts and treatment approaches in nonalcoholic fatty liver disease. Advances in Hepatology. 2014 2014: 7. 9- Lata J, Jurankova J, Kopacova M, Vitek P. Probiotics in hepatology. World Journal Gasteroentrology (WJG). 2011 17: 2890-2896. 10- Homayouni, A. Therapeutical effects of functional probiotic, prebiotic and symbiotic foods. Tabriz Unive Med Sci Iran. 2008. 11- Goldin BR, Gorbach SL. Clinical indications for probiotics: an overview. Clin Infect Dis. 2008 46: S96-100. 12- Lye HS, Kuan CY, Ewe JA, Fung WY, Liong MT. The improvement of hypertension by probiotics: effects on cholesterol, diabetes, renin, and phytoestrogens. Int J Molecular Sci. 2009 10: 3755-75. 13- Soltan Dallal MM, Yazdi MH, Hassan ZM, et al. The evaluation of probiotic effect of L.Acidophilus on the immune responses in BALB/C mice against transplanted tumor derived from breast tissue. J Zanjan Unive Med Sci. 2010 18: 37-48 14- Aller R, De Luis DA, Izaola O, et al. Effect of a probiotic on liver aminotransferases in nonalcoholic fatty liver disease patients: a double blind randomized clinical trial. Eur Rev Med Pharmacol Sci. 2011 15: 1090-5. 15- Shavakhi A, Minakari M, Firouzian H, Assali R, Hekmatdoost A, Ferns G. Effect of a probiotic and metformin on liver aminotransferases in non-alcoholic steatohepatitis: a double blind randomized clinical trial. Int J Prev Med. 2013 4: 531-537. 16- Ranadheera R, Baines SK, Adams MC. Importance of food in probiotic efficacy. Food Research International. 2010 43: 1-7. 17- De Vrese M, Schrezenmeir J. Probiotics, prebiotics, and synbiotics. Adv Biochem Eng Biotechnol. 2008 111: 1-66. 18- Liu JE, Zhang Y, Zhang J, Dong PL, Chen M, Duan ZP. Probiotic yogurt effects on intestinal flora of patients with chronic liver disease. Nurs Res. 2010 59: 426-32. 19- Ejtahed HS, Mohtadi-Nia J, Homayouni-Rad A, Niafar M, Asghari-Jafarabadi M, Mofid V. Probiotic yogurt improves antioxidant status in type 2 diabetic patients. Nutrition. 2012 28: 539-43. 20- Zar JH. Biostatistical analysis. 5th ed. New York: Pearson Press 1998. 21- Malaguarnera M, Vacante M, Antic T, et al. Bifidobacterium longum with fructo-oligosaccharides in patients with non alcoholic steatohepatitis. Dig Dis Sci. 2012 57: 545-53. 22- Loguercio C, De Simone T, Federico A, et al. Gut-liver axis: a new point of attack to treat chronic liver damage & quest. Am J Gastroenterol. 2002 97: 2144-6. 23- Eslamparast T, Poustchi H, Zamani F, Sharafkhah M, Malekzadeh R, Hekmatdoost A. The effects of dietary synbiotic supplementation on the liver enzymes, inflammatory markers and hepatic fibrosis in patients with nonalcoholic fatty liver disease: A double-blind randomized clinical trial. Iranian Journal of Nutrition Sciences & Food Technology. 2013 8: 1-8. 24- Vajro P, Mandato C, Licenziati MR, et al. Effects of Lactobacillus rhamnosus strain GG in pediatric obesity-related liver disease. J Pediatr Gastroenterol Nutr. 2011 52: 740-3. 25- Bhathena J, Martoni C, Kulamarva A, et al. Oral probiotic microcapsule formulation ameliorates non-alcoholic fatty liver disease in bio F1B golden Syrian hamsters. PLoS One. 2013 8: e58394. 26- Li Z, Yang S, Lin H, et al. Probiotics and antibodies to TNF inhibit inflammatory activity and improve nonalcoholic fatty liver disease. Hepatology. 2003 37: 343-50. 27- Karahan N, Isler M, Koyu A, et al. Effects of probiotics on methionine choline deficient diet-induced steatohepatitis in rats. Turk J Gastroenterol. 2012 23: 110-21. 28- Esposito E, Iacono A, Bianco G, et al. Probiotics reduce the inflammatory response induced by a high-fat diet in the liver of young rats. J Nutr. 2009 139: 905-11. 29- Paik HD, Park JS, Park E. Effects of Bacillus polyfermenticus SCD on lipid and antioxidant metabolisms in rats fed a high-fat and high-cholesterol diet. Biol Pharm Bull. 2005 28: 1270-4. 30- Kelishadi R, Farajian S, Mirlohi M. Probiotics as a novel treatment for non-alcoholic fatty liver disease a systematic review on the current evidences. Hepat Mon. 2013 13: e7233. 31- Ooi LG, Liong MT. Cholesterol-lowering effects of probiotics and prebiotics: A review of in vivo and in vitro findings. Int J Mol Sci. 2010 11: 2499-2522. 32- Liu JE, Zhang Y, Zhang J, Dong PL, Chen M, Duan ZP. Probiotic yogurt effects on intestinal flora of patients with chronic liver disease. Nurs Res. 2010 59: 426-32. 33- Kimoto H, Ohmomo S, Okamoto T. Cholesterol removal from media by lactococci. J. Dairy Sci. 2002 85: 3182-88. 34- Zhuang G, Liu XM, Zhang QX, et al. Mechanisms of the cholesterol-lowering effects of probiotics. Clin Lipidology. 2012 7: 501-7. 35- Jones ML, Chen H, Ouyang W, Metz T, Prakash S. Microencapsulated genetically engineered Lactobacillus plantarum 80 (pCBH1) for bile acid deconjugation and its implication in lowering cholesterol. J Biomed Biotechnol. 2004 1: 61-9.