<p>Biopolymers have attracted significant attention as sustainable, biocompatible, and biodegradable materials for applications in healthcare, food safety, and environmental protection. Their tunable chemical structures and ability to carry active agents make them promising candidates for developing antimicrobial materials. Among these, xanthan gum (XG), a high molecular weight anionic polysaccharide, exhibits excellent viscosity, film-forming, and gelation properties. Its hydroxyl- and carboxyl-rich structure enables diverse chemical modifications to enhance functional performance. Recent studies have focused on modifying XG to improve antimicrobial activity against bacteria, fungi, and biofilm-forming pathogens through mechanisms such as membrane disruption, ion release, nutrient chelation, biofilm inhibition, and controlled release of active agents. This review critically synthesizes these advances, analyzing structure-activity relationships, mechanisms of action, application areas, and safety considerations. Overall, the most promising modification strategies balance enhanced antimicrobial efficacy with biocompatibility and practical applicability, providing a roadmap for future development of XG-based antimicrobial materials.</p>