Fig. 1. Changes in the levels of serum cytokines, SCORAD index, and total serum IgE and comparisons before and after probiotic and placebo administration. SCORAD: SCORing Atoptic Derma- titis, IgE: immunoglobulin E, IL-2: interleukin-2, IL-4: inter- leukin-4, IL-5: interleukin-5, IL-6: interleukin-6, IL-10: inter- leukin-10, TNF-α: tumor necrosis factor-α, IFN-γ: interferon- γ, ECP: eosinophil cationic protein. a difference that was statistically significant (p=0.0015; Table 1, Fig. 1). As seen in Fig. 1, there was a decrease in the serum interleukin (IL)-5, IL-6 and interferon (IFN)-γ levels of the probiotic group after treatment. The difference between the post-treatment decreases in cytokines IL-5 (p=0.0012) and IL-6 (p=0.0016) and IFN-γ (p=0.0011) was statis- tically significant compared to the difference in decreases of these cytokines in the placebo group. The difference between the rates of post-treatment decreases in the serum levels of IL-2 (p=0.023), IL-4 (p=0.67), IL-10 (p=0.013), ECP (p=0.021), and tumor necrosis factor-α (TNF-α; p=0.437) and the rates of post-treatment decrease of these cytokines in the placebo group did not have statistical significance. The serum total IgE level decreased from 427±500 IU/ml to 281.9±405 IU/ml in the probiotic group. In the placebo group, the serum total IgE increased from 337.3 ±298 IU/ml to 347.7±271.3 IU/ml. The difference between the post-treatment serum IgE levels of the probiotic group and those of the placebo group was statistically significant (p=0.0035). DISCUSSION There is a growing interest in using probiotic supplements not only by consumers for its health-promoting effects on a daily basis but also by health care professionals for its The Effect of Probiotics in Atopic Dermatitis efficacy as a supplement and therapeutic product to treat a variety of medical conditions8. Probiotics affect allergic conditions on a number of levels. In the intestinal system, they inhibit the epithelial and mucosal adherence of pathogens and prevent their invasion through the epi- thelium9. Probiotics compete with pathogens for limited loci by their ability to adhere to intestinal epithelium and mucus. They also inhibit the proliferation of pathogens by consuming the nutrients in the intestine. Furthermore, the antibacterial potential of certain probiotic strains involves secretion of hydrogen peroxide, organic acids, and bacte- riocins that inhibit the growth of pathogens. Hydrolytic enzymes contribute to the increase of free fatty acids, short chain fatty acids, lactic acid, propionic acid, and butyric acid in the intestinal lumen, thus setting up an appropriate pH. Probiotics alter mucosal immunity consi- derably. This involves an increase in antibody production and activities of phagocytes and natural killer cells, modulation of the nuclear factor-κB pathway, and induc- tion of T-cell apoptosis10. In addition, probiotics have been shown to modify the structure of potential allergens that cause allergic diseases and alleviate their immuno- genicity11. Our results demonstrated an improved SCORAD index in both groups, but with higher levels in the probiotic group (65%) than in the placebo group (46%). In the probiotic group, a greater decrease of SCORAD index scores was shown after treatment in patients with high SCORAD index scores. However, this difference did not reach a statistically significant level (p=0.0015). SCORAD index of AD patients were evaluated before and after an eight-week intervention using a combination of the pro- biotics Lactobacillus paracasei Lpc-37, Lactobacillus acid- ophilus 74-2, and Bifidobacterium animalis subsp. lactis DGCC 420. It decreased by 15.5% in the probiotic group, while the decrease was only 8% in the placebo group12. In nine of thirteen randomized controlled trials studying the effectiveness of probiotics in the treatment or pre- vention of AD in children, the SCORAD index changed after one- or two-month probiotic administration13. There are other studies on the probiotic intervention indicating favorable results in the SCORAD index of AD pa- tients14-19. The serum total IgE level decreased from 427±500 IU/ml to 281.9±405 IU/ml in the probiotic group. In the placebo group, the serum total IgE increased from 337.3±298 IU/ml to 347.7±271.3 IU/ml. A significant difference was found between the probiotic and placebo groups regarding total IgE levels (p=0.0035). Our study showed probiotics to be effective in reducing AD patients’ serum IL-5, IL-6, and IFN-γ levels. A Vol. 24, No. 2, 2012 191