Hypoglycemic and Antioxidant Activities of Exopolysaccharides Produced by Lactic Acid Bacteria: A Systematic Review

Lactic acid bacteria (LAB) are widely utilized in various fermented food products and possess a Generally Recognized as Safe status. LAB produce exopolysaccharides (EPS), which are one of the components of postbiotics. Studies on EPS from LAB have attracted considerable interest because of their potential biological functions and associated health benefits, including hypoglycemic and antioxidant functions. However, there is still a lack of reviews that summarize available studies regarding the relationship between EPS characteristics and hypoglycemic and antioxidant activities. Therefore, the present systematic review aimed to identify the characteristics of EPS that influence its hypoglycemic and antioxidant activities. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Twenty-seven articles from Google Scholar, PubMed, and Scopus, which reported the sources of EPS-producing LAB, fermentation media, and conditions, as well as their EPS yields, molecular weights (MWs), and monosaccharide components, were selected based on the inclusion and exclusion criteria and whole literature screening. The MWs of EPS ranged from 10.75 to 9,549 kDa and from 2.4 to 9,549 kDa based on hypoglycemic and antioxidant activity assays, respectively. Generally, glucose and mannose were found in almost all EPS that were produced. This study indicated that MW and monosaccharide components influence hypoglycemic and antioxidant activities (in vitro). Further investigations with more comprehensive supporting data are needed to understand how all related factors influence EPS bioactivity.