Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 7 6 2016 02 01 338 341 EN Hassan Ghorbani-Choboghlo Mycology Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Taghi Zahraei-Salehi Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Javad Ashrafi-Helan Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran. Ramak Yahyaraeyat Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Hadi Pourjafar Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Donya Nikaein Academic Center for Education, Culture, and Research (ACECR), University of Tehran Branch, Tehran, Iran AND Mycology Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Asad Balal Mycology Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Ali Reza Khosravi Mycology Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. 2015 10 12 2015 10 16 Background and Objectives: Probiotic yeasts are used in production of functional foods and pharmaceutical products. They play an important role in promoting and maintaining human health. Until now, little work has been published on improving the survival of Saccharomyces in stimulated gastrointestinal condition. Material and Methods: In this study the exposure of the yeast in the capsulate and free forms to artificial gastrointestinal conditions was assessed and the number of viable Saccharomyces cerevisiae cells during 0 to 120 mines in these conditions was evaluated by a pour plate method using  sabouraud dextrose agar. Results: Results showed the shape of the beads was generally spherical, sometimes elliptical with a mean diameter of about 50–90 µm. Also count of viable probiotic cells obtained for all the microcapsules were above the recommended levels for a probiotic food. Also decrease of approximately 4 logs was noted in the number of free cells after 2 h of incubation at pH 2 and 8, when compared to decreases of about 2 logs in the all microencapsulated S. cerevisiae under similar conditions. Conclusion: It is concluded that microencapsulation process was significantly able to increase the survival rate of Saccha- romyces in a simulated gastrointestinal condition (p<0.05) https://ijm.tums.ac.ir/index.php/ijm/article/view/154 https://ijm.tums.ac.ir/index.php/ijm/article/download/154/538