Vaclav Vetvicka 1,* , Luca Vannucci 2, Petr Sima 2 and Josef Richter 3

1 Department of Pathology and Laboratory Medicine, University of Louisville, Louisville, KY 40292, USA
2 Department of Immunology, Institute of Microbiology, 142 20 Prague, Czech Republic; (L.V.); (P.S.)
3 Zdravotní ústav se sídlem v Ústí nad Labem, 400 01 Ústí nad Labem, Czech Republic;
* Correspondence:; Tel.: +1-502-852-1612; Fax: +1-502-852-1177

Glucans are part of a group of biologically active natural molecules and are steadily gaining strong attention not only as an important food supplement, but also as an immunostimulant and potential drug. This paper represents an up-to-date review of glucans (β-1,3-glucans) and their role in various immune reactions and the treatment of cancer. With more than 80 clinical trials evaluating their biological effects, the question is not if glucans will move from food supplement to widely
accepted drug, but how soon.

glucan; drug; immunity; food; supplement; infection; mushrooms