Nutritional Modulation of Impaired Blood-Brain Barrier Integrity and Function in Major Depression

Major Depressive Disorder (MDD) is increasingly linked to disruptions in blood-brain barrier (BBB) integrity, contributing to neuroinflammation and impaired brain homeostasis. While traditional antidepressant therapies often fail to achieve full remission, growing evidence suggests that specific dietary compounds may offer novel avenues for restoring BBB function and improving mental health outcomes. This review explores the potential of selected nutrients-omega-3 fatty acids, vitamin D, sulforaphane, fucoidan, and urolithins-to modulate BBB integrity through anti-inflammatory, antioxidant, and transporter-regulatory mechanisms. These compounds act by reinforcing tight junctions, reducing matrix metalloproteinase activity, and modulating efflux transporters such as P-glycoprotein. Although current evidence is largely preclinical, the mechanistic insights provided in this review support the rationale for integrating nutritional strategies into the management of MDD. Future clinical studies are needed to validate these findings and develop biomarker-driven approaches for targeting the BBB in nutritional interventions for psychiatric disorders.