Multiple antibiotic-resistant bacteria are a big problem. Slow-releasing nanometals with natural polymers can prevent antibiotic resistance. Polymer science and technology emphasizes functional carbohydrate polymers. The affordability, availability, renewability, and biodegradability of these polymers make them useful. Chemically combining sugar components creates unusual materials that can be easily manipulated. Metal-based nanocomposites are attractive due to their chemical and physical properties. Mixing metal nanoparticles with glass, ceramic, and polymers creates antibacterial nanocomposites. A polymer/metal nanocomposite using the polymer phase as a stabilizer, template, or protective agent has numerous advantages in battling microorganisms. Functionalized carbohydrate polymers-based metal nanocomposites carry nanoparticles and may be antimicrobial. The newest manufacturing methods and antibacterial-focused antimicrobial mechanisms are provided. These carbohydrate nanocomposites inhibited S. aureus and E. coli. Antifungal activity against C. albicans shows antimicrobial potential. Long-term activity is surface-focused. Antimicrobial mechanisms are unclear. Metal nanocomposites that inactivate bacteria with antimicrobial carbohydrate polymers have progressed recently. This chapter addresses carbohydrate polymer-based metal nanocomposites’ numerous applications. They are effective antimicrobials used in food packaging, wound dressings, water treatment, anticancer, and dentistry.