PURPOSE: The gastrointestinal (GI) tract is a highly immunologically active organ where coordinated crosstalk between Toll-like receptor 4 (TLR4) and NLRP3 inflammasome maintains epithelial integrity, supports mucosal repair, and promotes immune tolerance. This review aims to summarize current understanding of TLR4-NLRP3 interactions in the gut, examine their in disease, examine their roles in disease, and evaluate emerging therapeutic strategies targeting this axis.
METHODS: A comprehensive review of recent literature was conducted, focusing on regulatory mechanisms governing TLR4-NLRP3 signaling under homeostasis and dysregulation. Studies addressing epithelial barrier function, cytokine signaling, pyroptosis, metabolic endotoxemia, dysbiosis, and gut-brain axis communication were examined. Research using organoids, gut-on-chip system, microbiota modulation, and multi-omics approaches was also evaluated to understand therapeutic and translational advancements.
RESULTS: Findings indicate that balanced TLR4-NLRP3 signaling preserves epithelial barrier integrity, regulates inflammatory responses, and supports immunological tolerance. Dysregulation disrupts these protective mechanisms and initiates feed-forward cycle of epithelial damage, metabolic endotoxemia, dysbiosis, and heightened cytokine-driven inflammation. Such aberrant activity contributes to major intestinal diseases-including inflammatory bowel disease, necrotizing enterocolitis, and colorectal cancer-as well as extraintestinal conditions such as obesity, type 2 diabetes, and neuroinflammation through gut-brain axis pathways. Novel therapeutic strategies, including selective small-molecule inhibitors and microbiota-based interventions, show potential for targeted modulation.
CONCLUSION: The TLR4-NLRP4 axis is a context-dependent regulator of gut and systemic immunity. Targeted modulation of this pathway represents a promising strategy to restore immune homeostasis while preserving host defense, supporting its relevance as a translational therapeutic target across multiple immune-mediated disorders.
