Understanding Exopolysaccharides from Lactic Acid Bacteria: Synthesis, Functions, and Applications.

Exopolysaccharides (EPS) are among the most significant metabolites generated by lactic acid bacteria (LAB). This review aims to summarize the current knowledge on EPS, focusing on three main aspects: the biosynthetic pathways of EPS, its health-promoting functions, and its applications in food products. First, EPS are primarily synthesized through the extracellular synthesis pathway and the Wzx/Wzy-dependent pathway, although the mechanisms underlying EPS synthesis remain unclear. Second, EPS have demonstrated significant potential in antimicrobial activity, antioxidant activity, gut microbiota regulation, immune modulation, lipid metabolism regulation, antitumor properties, and other emerging functions. Nevertheless, clinical data supporting these benefits remain limited. Lastly, EPS can be applied in dairy- and cereal-based products to enhance their quality, which, however, remains in the experimental stage. Therefore, future research should prioritize the in-depth analysis of EPS synthesis mechanisms, the expansion of clinical data to evaluate its functions, and the optimization of production processes and addition strategies.