Prolonged Intestinal Ethanol Absorption and Oxidative Stress: Revisiting the Gut-Liver Axis in Alcohol-Associated Disease.

Chronic alcohol consumption induces oxidative stress not only in the liver but also in the gastrointestinal tract, where prolonged intestinal ethanol absorption plays a pivotal and underrecognized role. This review reframes ethanol pharmacokinetics to emphasize sustained jejunal and ileal uptake, which maintains elevated blood alcohol levels and perpetuates redox imbalance across the gut-liver axis. We integrate recent findings on ethanol-induced barrier dysfunction, CYP2E1-mediated ROS production, microbial dysbiosis, and mitochondrial disruption, proposing that the intestine is an active site of injury and a driver of systemic inflammation. Key mechanistic insights reveal that gut-derived endotoxins, compromised epithelial integrity, and microbiome-mitochondria interactions converge to exacerbate hepatic and extrahepatic damage. We further explore emerging therapeutic strategies-ranging from NAD repletion and probiotics to fecal microbiota transplantation-that target this upstream pathology. Recognizing prolonged intestinal ethanol absorption as a clinically meaningful phase offers new directions for early intervention and redox-based treatment in alcohol-associated disease.