Oxidative Stress-Gut Microbiome Crosstalk: Intestinal Redox Imbalance and Probiotics Therapeutic Potential

Oxidative stress and gut microbiota dysbiosis establish a self-perpetuating loop that disrupts epithelial barrier integrity and fuels chronic inflammatory and metabolic disorders, including inflammatory bowel disease (IBD), metabolic syndrome (MS), and chronic kidney disease (CKD). This systematic review synthesizes mechanistic, preclinical, and clinical evidence linking reactive oxygen species (ROS), microbiota-derived metabolites, and host redox homeostasis, with a focus on probiotic-based interventions. Comprehensive searches of PubMed, Scopus, Web of Science, and Google Scholar (2000-March 2026) identified in vitro, animal, and human studies, as well as systematic reviews and meta-analyses, assessing oxidative biomarkers, microbiome profiles, and barrier function outcomes. Probiotic strains, predominantly Lactiplantibacillus, Bifidobacterium, and emerging next-generation taxa, attenuate oxidative stress by inducing antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPx)], activating Nrf2 signaling, and restoring short-chain fatty acid (SCFAs) production, thereby lowering malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) while enhancing total antioxidant capacity (TAC). At the mucosal interface, probiotics strengthen tight junction proteins, suppress NF-κB-mediated cytokine release, and mitigate dysbiosis, contributing to clinically meaningful improvements in disease activity, insulin sensitivity, and uremic toxin burden along gut-liver, gut-kidney, and other gut-organ axes. Overall, current evidence supports probiotics and synbiotics as promising adjuncts for nutrition-driven redox modulation, while highlighting the need for strain-resolved, multi-omics, multicenter trials with standardized redox and microbiome endpoints to optimize dosing strategies and long-term safety.