Protection against this parasite has been largely associated with cell-mediated immune response and production of interferon gamma (IFN-γ) (3-4). Epithelial cells

Cryptosporidiosis, an opportunistic parasitic disease, has become a topic of great interest being life-threatening among immunocompromised patients worldwide. To date, there is no totally effective therapy other than a healthy intact immune system. Probiotics, widely reported to stimulate both innate and acquired immunity at mucosal and systemic levels, were investigated in the present study for the therapeutic effects of daily administration of a mixture of L. acidophilus, L. helveticus and Bifidobacterium bifidum against Cryptosporidium parvum (genotype 2) infection in an immunosuppressed mouse model. Although complete eradication of the parasite was not achieved, but the used probiotics mixture induced significant reduction in parasite burden, ultrastructural changes in relation to parasite attachment, and internalization to epithelial cells, partial reparation of the parasite-induced intestinal mucosal damage and increase in the serum level of IFN-γ. These results reveal beneficial effects of probiotics upon cryptosporidiosis and indicate that they could help in reducing the risks of severe disease in immunosuppressed patients. Hopping for a more beneficial role against cryptosporidiosis, further studies are recommended to exploit the role of specific strains in therapeutic intervention, and possibility of their combination with chemotherapeutic agents. Keywords—Cryptosporidium parvum (genotype 2), immunosuppressed mouse model, probiotic bacteria, parasite burden, intestinal mucosa, electron microscopy, IFN-γ.