Regulation of Intestinal Permeability in Health and Disease: Possible Therapeutic Applications

Intestinal permeability is the process by which certain substances pass through the intestinal barrier and enter the bloodstream to reach the tissues and organs where they are needed. This vital process is regulated by various physiological mechanisms, depending on the type of molecule being translocated, from ions and water molecules to large peptides and vitamins. However, under certain conditions, intestinal permeability can increase, exposing the body to the passage of unwanted molecules and pathogenic microorganisms. The various mechanisms involved in increased intestinal permeability include the zonulin pathway, intestinal epithelial cell death, intestinal dysbiosis, and transcytosis. Each of these mechanisms is activated by certain stimuli, and may occur in isolation or together. The translocation of molecules and pathogens has been linked to the development or worsening of certain pathologies, such as acute pancreatitis, sepsis, inflammatory bowel diseases, irritable bowel syndrome, celiac disease, systemic lupus erythematosus, obesity, depression, and schizophrenia. This is mainly due to the inflammatory response generated in response to the translocated microorganisms. Research has been conducted to develop therapies to decrease intestinal permeability in several diseases. This review summarizes knowledge related to pathways that regulate intestinal permeability, diseases associated with increased intestinal permeability, and advances in potential treatments.