Natural Bioactive Compounds Targeting Gut Barrier Integrity and Metabolic Endotoxemia in Cardiometabolic Disease: Mechanistic Insights and Translational Perspectives

Cardiometabolic diseases are increasingly recognized as disorders of chronic low-grade systemic inflammation and gut barrier dysfunction that mutually reinforce one another. Each condition amplifies the other through progressive injury to the intestinal epithelium. Compromise of the mucus layer, altered tight junction dynamics, dysbiosis, and impaired epithelial restitution promote intestinal permeability and enable the translocation of lipopolysaccharide and other microbial products into the circulation, thereby inducing metabolic endotoxemia. This gut derived inflammatory signal activates Toll like receptor 4, nuclear factor kappa B, and inflammasome associated pathways, linking barrier dysfunction to insulin resistance, hepatic steatosis, adipose tissue inflammation, endothelial activation, and vascular injury. Here, we examine the gut barrier as an immunometabolic interface and synthesize current evidence connecting its disruption to endotoxin driven cardiometabolic pathology. We further evaluate selected natural bioactive compounds, including curcumin, resveratrol, quercetin, epigallocatechin gallate, berberine, anthocyanins, omega 3 polyunsaturated fatty acids, and dietary polysaccharides, as gut targeted interventions capable of reinforcing junctional integrity, restoring mucus and microbial homeostasis, lowering endotoxin burden, and attenuating inflammatory signaling. Finally, we highlight the principal translational barriers that currently limit clinical implementation, including pharmacokinetic variability, microbiota dependent biotransformation, source standardization, and the lack of robust, standardized biomarkers of barrier restoration and metabolic endotoxemia.