Polysaccharide materials are often called superwetting antibacterial systems because they swell or have a low initial water contact angle. But these measurements do not show that the materials kill bacteria or control biofilms. This review looks at polysaccharide-based superwetting and hydrated interfaces, including coatings, polymer brushes, porous membranes, fibrous layers, hybrid interfaces, and selected hydrogels. Hydrophilic and hydrated systems are included to help compare how these interfaces work, but their inclusion does not mean they show superwetting behavior. We assessed studies in five separate categories: quantitative wetting, interfacial hydration, bacterial adhesion, bacterial viability and biofilm response. We also examined whether wetting and biological performance persisted after exposure to proteins, salts, flow, wear and sterilization. Among the representative systems audited in this review, none reported quantitative wetting, retained wetting after relevant conditioning, and an antibacterial endpoint using matched specimens from the same preparation batch, subjected to the same conditioning protocol, and evaluated against matched controls. Hydrated polysaccharide interfaces can reduce protein adsorption and bacterial attachment. Reported bactericidal effects involved cationic groups, released drugs, metal or oxide phases, or light-activated treatment; hydration alone was not established as the cause of killing. A combined material needs two measurements: retained hydration with reduced attachment, and active killing at a reported exposure.