The intestinal epithelium is exposed daily not only to components of food but also to potentially immune-activating bacteria, yeasts, and moulds, and numerous toxic substances. These include food additives, metals from food or dental restoration, and other orally ingested foreign substances. The immune system associated with the intestine and a complex biofilm (microbiome) continually ensure that the boundary layer function is intact (integrity of the mucosa).
When there is a disorder of the intestinal barrier (leaky gut), the specified immunogenic stimulus factors can increasingly penetrate the mucosa boundary layers. For the immune system associated with the intestine, this increased confrontation with the foreign substances also results in decreased capacity for immune tolerance. Apart from allergens increasingly breaking through (e.g. components of food, food additives, metals), other consequences are the colonisation of foreign germs in the intestine and alterations in the intestinal mucosa caused by inflammation. The intestinal mucosa becomes not only an inflamed area itself (which in turn worsens the leaky gut) but also the source of systemic inflammation.
Resulting phenomena associated with leaky gut include: