Palmitic Acid and Intestinal Barrier Integrity: A Systematic Review of Molecular Mechanisms Involving Tight Junction Proteins, Oxidative Stress, and Inflammatory Signaling

The integrity of the intestinal barrier is crucial for metabolic and immune balance, but it can be disrupted by excessive exposure to palmitic acid, a saturated fatty acid common in food. This study examines the mechanisms of such disruption through a systematic review of 41 articles published from 2020–2026 from Scopus using the PRISMA framework. The results indicate that palmitic acid reduces the expression and stability of tight junction proteins, triggers oxidative stress and mitochondrial dysfunction, and activates the TLR4/NF-κB inflammatory pathway. These three processes mutually reinforce each other, leading to increased intestinal permeability. These findings underscore the need for clinical validation and preventive or therapeutic approaches targeting structural damage, oxidative stress, and inflammation in an integrated manner.