Exopolysaccharides (EPS) are extracellular macromolecules excreted as tightly bound capsule or loosely attached slime layer in microorganisms. They play most prominent role against desiccation, phagocytosis, cell recognition, phage attack, antibiotics or toxic compounds and osmotic stress. In the last few decades, natural polymers have gained much attention among scientific communities owing to their therapeutic potential. In particular the EPS retrieved from probiotic bacteria with varied carbohydrate compositions possess a plenty of beneficial properties. Different probiotic microbes have unique behavior in expressing their capability to display significant health promoting characteristics in the form of polysaccharides. In this new era of alternative medicines, these polysaccharides are considered as substitutes for synthetic drugs. The EPS finds applications in various fields like textiles, cosmetics, bioremediation, food and therapeutics. The present review is focused on sources, chemical composition, biosynthetic pathways of EPS and their biological potential. More attention has been given to the scientific investigations on antimicrobial, antitumor, anti-biofilm, antiviral, anti-inflammatory and immunomodulatory activities.

胞外多糖（EPS）是微生物中以紧密结合的胶囊或松散附着的粘液层形式排出的细胞外大分子。它们在对抗干燥、吞噬作用、细胞识别、噬菌体攻击、抗生素或有毒化合物以及渗透压方面发挥着最突出的作用。在过去的几十年中，天然聚合物由于其治疗潜力而受到科学界的广泛关注。特别是从具有不同碳水化合物成分的益生菌中提取的 EPS 具有许多有益的特性。不同的益生菌微生物具有独特的行为，以多糖的形式表现出显着的健康促进特性。在这个替代药物的新时代，这些多糖被认为是合成药物的替代品。EPS 可应用于纺织品、化妆品、生物修复、食品和治疗等各个领域。本综述的重点是 EPS 的来源、化学成分、生物合成途径及其生物潜力。抗菌、抗肿瘤、抗生物膜、抗病毒、抗炎和免疫调节活性的科学研究受到更多关注。