Research Progress of Microbial Levan-type Fructan and Its Probiotic Functions

Levan-type fructan is a natural homo-polysaccharide with a β-(2, 6) glycosidic bond as its main chain and a small amount of β-(2, 1) glycosidic bond as a branch chain. Fructan in nature is mainly derived from sucrose polymerization catalyzed by microbial levansucrase. Since levan has many important biological properties, such as antitumor, hypoglycemic, hypolipidemic etc., it has great potential for development and utilization in biomedicine, food and pharmaceutical fields. This article describes the properties and biosynthetic pathway through the levansucrase of levan, and the probiotic functions including promoting the growth of probiotics, inhibiting the growth of harmful bacteria, activating immune factors, hypoglycemic, hypolipidemic, anti-oxidation and antitumor are reviewed. In addition, it also analyzes the current challenges of levan and provides scientific ideas for the potential commercialization of levan.