Gut epithelial barrier and blood–brain barrier (GEB/BBB)

The gut epithelial barrier and the blood-brain barrier (BBB) are complex physiological systems that serve as the primary gatekeepers for the body's internal environment and the central nervous system, respectively. The gut barrier consists of a single layer of epithelial cells joined by tight junctions that regulate the absorption of nutrients while preventing the entry of luminal pathogens and toxins (PubMed: 23426535). The BBB is a highly specialized endothelial interface that maintains the unique microenvironment of the brain by restricting the passage of solutes and potentially harmful substances from the blood (PubMed: 16625214). These barriers are functionally linked through the gut-brain axis, where increased intestinal permeability (often termed 'leaky gut') can trigger systemic immune responses that subsequently compromise BBB integrity, contributing to neurodegenerative and autoimmune disorders (PubMed: 25880519). While not a single molecular target, specific components of these barriers, such as tight junction proteins (claudins, occludins) and efflux transporters (P-glycoprotein), are major focuses for drug delivery strategies and therapeutic intervention in inflammatory and neurological diseases.

Other names

Intestinal mucosal barrierBlood-cerebral barrierGut-brain axis barriersIntestinal epithelial barrier

Modulation of tight junction assembly, inhibition of ATP-binding cassette (ABC) efflux transporters, and osmotic disruption of endothelial cell-cell junctions.