Extracellular carbohydrate polymers secreted by different species of bacteria, commonly known as bacterial exopolysaccharide (EPS), classified as heteropolysaccharide (HePS) and homopolysaccharide (HoPS) play a very important role in bacterial pathogenicity. The slime layer or capsular material formed by these bacterial exopolysaccharides facilitates the attachment of the pathogen to the host cell. Besides pathogenic bacteria, many common environmental bacteria also secrete EPS as a measure of their stress tolerance and adaptation to the hostile environment. Bacterial exopolysaccharide is the key component of the biofilm produced by few species of bacteria to survive in adverse environment. The immunomodulatory, anti-allergic, anti-inflammatory effects of such EPS has made it a definite prebiotic supplement. EPS positively stimulates gut health by preventing attachment of pathogenic microbes to the intestinal mucosa while influencing the growth and proliferation of beneficial gut microbiota. Modulation of host innate and adaptive immune response by EPS is a complex phenomenon involving interaction, recognition, and regulation. The carbohydrate materials impinged into the EPS layer can also be utilized by diverse group of beneficiary microorganisms. The commercial benefits of such exopolysaccharides are well established in the field of food, biomedicine, cosmetic, and pharmaceutical industry. Commercialization of bacterial EPS as prebiotic supplement is under review with different dairy, non-dairy, and meat products. Though the extensive use is still under consideration due to difficulties in commercial high yield production of EPS, however its bio thickening properties exerted at low concentration is acting as an added advantage of structural and functional food production. In this chapter, all these aspects of bacterial EPS as prebiotic supplements have been thoroughly discussed.