Introduction: Systemic inflammation plays a main role in the incidence of diabetes complications. Probiotics can be used in the treatment of diabetes complications for its anti-inflammatory properties. This study aimed to investigate the effects of probiotic supplement on glycemia, insulin resistance and inflammatory markers in patients with type 2 diabetes. Materials and Methods: This randomized double blind clinical trial was carried out on 59 diabetic patients, aged 25-65 years, referred to the Taleghani Hospital in Tehran. They were randomly divided in 2 groups, the probiotic and the placebo. Patients in each group received 2 capsules per day for 6 weeks. Fasting blood samples were taken at baseline and after intervention to evaluate glycemic control, insulin resistance and inflammatory biomarkers. Results: Mean fasting blood glucose was significantly decreased by 9% (132.7±34 vs. 146.5±44) in the probiotic group during the intervention (P=0.001). Results of the analysis of covariance showed that there were statistically significant differences between the two groups in fasting blood glucose and insulin resistance, whereas there were none observed in IL-6 and TNFα between the two groups after intervention. Conclusions: The results of the present study indicate that probiotic consumption may help in diabetes control through reducing glycemia and insulin resistance.