Definition of Intestinal Permeability
Intestinal permeability also known as ‘leaky gut’ has gained researchers attention in recent years, with the overwhelming amount of evidence linking the integrity of the intestine to health and disease. The exact definition of intestinal permeability remains poorly understood. However, the current definition describes intestinal permeability as the loss of integrity between the cells of the small intestine caused by the disassembling of the transmembrane proteins.
The classification of intestinal permeability can be divided into two major categories, namely acute intestinal permeability and low-grade chronic intestinal permeability. Firstly, acute intestinal permeability is more common within a hospital setting where pathogenic bacteria trigger a change in intestinal integrity, resulting in sepsis. Acute intestinal permeability is seen in conditions such as pancreatitis and burn injuries. Whereas, low-grade chronic intestinal permeability appears to be more prominent in health conditions found within clinical practice.
A Brief History of Intestinal Permeability
The concept that pore size varies at different levels of intestine was first established in the literature during the early 1960s and collectively referred to as the ‘intestinal-pore hypothesis’. During the early 1970s research emerged surrounding the association between intestinal permeability and coeliac disease, with preliminary data suggesting that the degree of intestinal permeability correlates with the severity of coeliac disease. More recently, the mechanism of action for intestinal permeability development was discovered, strengthening the understanding of the involvement of intestinal permeability in health and disease. However, currently, Intestinal permeability is not officially recognised as a medical condition with the closest diagnosis classified as K59.9 functional intestinal disorder. Intestinal permeability may thereby be considered as an intestinal reaction in response to a stimulus and not a condition nor syndrome.