College of Science, University of Al-Mustansiriyah discussed a Ph.D. thesis on the production and characterization of dextran as a probiotic and its effect against Candida spp by the postgraduate student, Mrs. Aya Ali Hamid. The thesis aimed at producing therapeutic dextran from probiotic bacteria and investigating its inhibitory effects against virulence factors of Candida isolates. The thesis demonstrated using of modern techniques in the characterization of the biopolymer of the product, most notably (TLC, FE-SEM, FTIR, HNMR, GC-MS, WSI and WHC) and the extraction, purification and characterization of therapeutic dextran. The thesis concluded the ability of the probiotic bacteria to produce the therapeutic extract (dextran) in appropriate quantities and with high quality specifications, and its ability to inhibit the growth, vitality and virulence factors of the pathogenic Candida yeast inside and outside the body.