Methods: Iranian cheese samples were collected from Ardabil province. Enterococci spp were isolated using selective culture mediums and identified using API kites. Inhibitory effects of isolated Enterococci on growth of Pseudomonas aeruginosa and intestine pathogens (Shigella dysenteriae, Escherichia coli and Salmonella typhimurium) were tested using agar well method . In order to study probiotic activities of isolated bacteria in live animals, NMRI mice were divided into different groups and Enterococci was administrated orally (1 ML/mouse) with doses equal to 2 (6×10⁸ cfu/ml) 3 (9×10⁸ cfu/ml) and 4 (12×10⁸ cfu/ml) MacFarland standard for 2 weeks. After two weeks continues treatment, blood samples were collected from retroorbital sinus and serum levels of cholesterol, triglycerides, LDL and HDL measured using enzymatic method. Interleukins (IL-2, IL-6 and IL-10) levels were measured using ELISA kites.

  Results: Results of this study demonstrated that treatment with faecium species decreases serum cholesterol and increases serum IL-10 level, while it has not showed significant effects on serum levels of glucose, triglycerides, IL-2 and IL-6 (p<0.05). Administration of faecalis species have no significant effects on lipid levels of serum ( p <0.05). Moreover, results revealed that treatment with faecalis species increased IL-6 and IL-10 ( p <0.05). None of the species affected pathogens growth significantly ( p <0.05).

  Conclusion: The results obtained from current study demonstrate that continues treatment with both species can affect immune functions of animal by altering the cytokines profile and treatment with faecium species decreases serum level of cholesterol.