Leaky Gut Syndrome
Leaky Gut Syndrome (LGS) or Increased Intestinal Permeability describes a condition where the intestinal wall has lost its ability to prevent large molecules from breaching the gut barrier and consequently allows macromolecules (food proteins), antigens and toxins to make their way to the bloodstream.
The healthy intestinal mucosa ordinarily allows only small molecules – amino acids, simple sugars, fatty acids, vitamins, and minerals –to cross the gut barrier into the blood stream. The surfaces of intestinal cells have specialised carrier proteins that allow these specific nutrients through, but keep larger molecules within the gut.
What Causes Leaky Gut Syndrome?
A large number of factors can lead to leaky gut:
Fermentation of certain dietary components (proteins, refined carbohydrates) leads to potentially harmful end-products: ammonia, amines, phenols, sulfides, leading to dysbiosis. These compounds also reduce the lifespan of mucosal cells. Food additives, alcohol and caffeine also irritate the gut wall.
As well as leading to dysbiosis, stress reduces blood flow to the gut leaving it unable to repair itself. Stress also causes the cells of the intestine to contract which results in larger gaps between cells.
Food allergies and intolerances
Intolerance to certain foods (e.g,lactose) can lead to gut inflammation.
Consequences of Leaky Gut
Altered permeability of the intestinal wall can have highly detrimental effects, including:
May develop as the nervous system becomes sensitised.
Carrier cells are less able to transport nutrients in damaged or inflamed mucosal cells.
Increased absorption of environmental toxins
Gut mucosa is normally an effective barrier against environmental chemicals that are present in food (some e-numbers, pesticides, PCBs).
When able to pass into the circulation, these toxins can cause damage to organs, notably the liver and the brain.
Multiple Chemical Sensitivities may develop as the nervous system becomes sensitised.
Development of allergies and auto-immune reactions
As partially digested, large molecules pass into the bloodstream, the immune system recognises them as foreign and raises antibodies against them. Allergies to many types of foods are an inevitable consequence, and a vicious cycle results where allergies lead to gut inflammation, which in turn leads to more intestinal permeability. Some of the molecules that reach the bloodstream may share a similar epitope to human tissue proteins. Antibodies against these molecules will attack the bodies own cells, leading to auto-immune diseases.
Chronic activation (inflammation) of the immune system
A bacterial compound that can easily make its way into the bloodstream is lipopolysaccharide (LPS). LPS is part of the cell wall of bacteria and is in itself a potent endotoxin. When endotoxins appear in the bloodstream they induce a strong pro-inflammatory response with the production of inflammatory cytokines such as IL-1, IL-6, and TNF-alpha. Such a chronic inflammatory condition is commonly observed in Chronic Fatigue Syndrome (CFS/ME).
LPS also induces the production of Nitric Oxide (NO) and when NO is increased, natural killer cell function is inhibited and opportunistic infections such as mycoplasma are more likely. Herpes viruses also tend to reactivate in a context of immune activation and are also frequently detected.
Testing for Leaky Gut Syndrome
IBS clinics uses a number of “leaky gut” tests including the Cyrex Array 2 Intestinal permeability profile and the PEG400 Gut permeability profile offered by Biolab.