EPS-producing Leuconostoc as probiotics: biomedical potential and structure–function perspectives

With the increasing prevalence of diseases associated with gut dysbiosis, such as gastrointestinal diseases, immunological disorders, metabolic and cardiovascular diseases, and cancer, there is a growing need for effective strategies to restore the gut microbiota and promote overall health. In this context, underexplored lactic acid bacteria, particularly those capable of producing exopolysaccharides (EPSs), are gaining attention due to the diverse and pleiotropic health benefits of their EPSs. This narrative review provides an overview of the health-promoting properties of Leuconostoc species and their associated EPSs, with particular emphasis on the structure–function relationships underlying EPS bioactivity. Furthermore, it examines the mechanisms through which EPS-producing Leuconostoc strains may influence gut and systemic health and discusses their potential as next-generation microbiome-based interventions. Notably, most available evidence is derived from in vitro and other preclinical models, while clinical studies directly validating the efficacy and health benefits of Leuconostoc EPSs in humans remain limited.