The health of the gastrointestinal tract is vital to the competence of the immune system and subsequent inflammatory responses. The intestinal epithelium or lining of the gut (specifically the small intestinal mucosa) is a selectively permeable barrier which regulates the movement of ions and water across it, enabling the transport of nutrients, whilst also preventing pathogenic and commensal bacteria from entering the blood stream.
This epithelial layer is a complex structure containing among other components, tight junctions that form a selective seal between adjacent epithelial cells, which is crucial to the regulation of intestinal permeability. An array of foreign antigens from food sources access the epithelial surface of the small intestine, where there is a concentration of immune tissue that has evolved to create tolerance without triggering an immune inflammatory response. However, high physical or mental stress, medication, enzyme and nutrient deficiencies, an imbalanced microbiome, small intestinal bowel overgrowth (SIBO) and dysregulation of the immune response, can all lead to a disruption of the tight junctions and an increase in intestinal permeability, often referred to as ‘Leaky Gut’.
Intestinal permeability or leaky gut is a term used when large protein molecules, mostly food antigens and microbial fragments, breach the intestinal barrier and are allowed through into the blood stream, where they can initiate an immune system response. The gut contains the greatest concentration of immune tissue in the body and therefore when the intestinal barrier function is impaired, an immune system response is readily initiated.
The resultant cascade of inflammatory responses that are subsequently activated, include the release of IgG antibodies and cytokines, which further increases the intestinal permeability, thus enabling the translocation of dietary antigens to other parts of the body. The circulating antibodies in the bloodstream form immune complexes that can then trigger inflammatory conditions within specific bodily tissues if they are not removed from the body. Research shows that these can include migraine and digestive problems like IBS. There may well be a genetic component with some individuals having a genetic susceptibility and other environmental factors. The IgG antibodies to the food antigens can be identified in IgG food intolerance tests such as FoodPrint and Food Detective. Removing the food triggers and promoting the healing of the gut may reduce or resolve the inflammatory response and thereby the symptoms.