Gut Microbiota-Driven Pathways Linking Chronic Stress to Tumor Progression

Chronic stress is increasingly recognized as a critical factor influencing tumor progression, but its underlying mechanisms remain incompletely understood. This review examines the role of gut microbiota as a critical mediator linking chronic stress to tumor progression. Recent evidence suggests that chronic stress triggers gut dysbiosis, characterized by reduced microbial diversity, depletion of beneficial bacteria, and enrichment of potentially harmful species. We summarize the mechanisms by which chronic stress regulates gut microbial dysbiosis, including stress-related hormone signaling, intestinal inflammation, mucosal barrier disruption, and altered gut motility. Additionally, we examine how stress-induced dysbiosis contributes to tumor progression through immune suppression, metabolic reprogramming, enhanced tumor stemness, and potentially through barrier dysfunction, and chronic inflammation. We further discuss potential therapeutic interventions, including specific probiotics, prebiotics and other strategies that may help suppress tumor development by modulating the stress-microbiota-cancer axis. In conclusion, these emerging insights provide a foundation for novel therapeutic strategies that target the stress-microbiome-cancer axis, which may help suppress tumor progression and complement conventional cancer treatments to improve clinical outcomes in cancer patients.