Dietary polyphenols as functional food bioactives: Nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant and immunomodulatory mechanisms in combating bacterial infections

The rising threat of antimicrobial resistance (AMR) highlights the need for novel strategies to fight against microbial pathogens while strengthening host defenses. Dietary polyphenols abundant in fruits, vegetables, and food byproducts, could offer dual antimicrobial and host-protective effects. At the same time, nuclear factor erythroid 2-related factor 2 (Nrf2) activation emerges as one of key mechanisms that extend beyond antioxidant control to regulate cytokine production and innate immune signaling. This review discusses the underexplored role of polyphenol in activating Nrf2 as a signaling hub that coordinates host immune responses against bacterial infection. Despite bioavailability hurdles, polyphenols could offer a promise direction for functional foods-based strategies in infection control. Schematic representation of activating the Nrf2 pathway by polyphenol rich food against bacteria • Dietary polyphenols exhibit antioxidant, antibacterial, and immunomodulating efficacy. • Explores dietary polyphenols as modulators of host defense against bacterial infection. • Highlights Nrf2-mediated epithelial barrier integrity and redox–immune homeostasis. • Polyphenols offer a food-based strategy to support host defense and resilience.