The GIT is part of the digestive system that consists of the stomach and intestines. The GIT is responsible for digesting and breaking down the foods from your diet and nutrient absorption and contains gut-associated lymphoid tissue (GALT) for immune support. The lining of the GIT forms the mucosal intestinal barrier.
Healthy intestinal barrier function
Healthy intestinal barrier function is important for both digestive and immune health. The intestinal barrier acts as the gateway between the GIT and bloodstream and is composed of a single layer of cells lining the GIT which mainly consist of enterocytes (intestinal absorptive cells) and tight junctions (sit between the enterocytes). When the intestinal barrier becomes damaged, it is often referred to as ‘leaky gut’, where the tight junctions become ‘loose’, allowing unwanted substances to enter the bloodstream.
The mucosal intestinal barrier is a selective barrier coated in a layer of mucus which allows essential dietary nutrients, electrolytes and water from the intestines into the bloodstream and helps to prevent the passage of unwanted substances, such as food antigens, endotoxins and pathogenic microorganisms.
Loss of intestinal barrier integrity is associated with:
- Digestive disturbances
- Inflammation of the GIT
- Impaired immune system function
- Impaired GIT immune function
- Pathogenic microorganisms
- Impaired digestive enzyme activity, particularly for proteins
- Hypochlorhydria (low stomach acid)
- Nutritional deficiencies
- Gut-brain axis dysfunction
Supporting the intestinal barrier with herbs and nutrients
- Aloe vera inner leaf juice or gel provides demulcent activity that soothes irritated tissues and supports GIT mucous membrane health. Aloe vera maintains digestive and gastrointestinal system health and function.
- Calendula provides anti-inflammatory activity to relieve inflammation and supports healthy digestive and gastrointestinal health and function. Calendula is traditionally used in Western herbal medicine (WHM) as an anti-inflammatory to help relieve mild GIT inflammation and as a vulnerary for wound healing.
- Licorice is traditionally used in WHM as a demulcent to soothe the GIT mucous membranes. Deglycrrhizinated Licorice (DGL) is a specialised form of Licorice typically containing less than 3.5% glycyrrhizin. Glycyrrhizin mimics aldosterone activity which increases sodium reabsorption and potassium excretion, which is responsible for many of the side effects associated with Licorice. Having a low glycyrrhizin extract is a good option for digestive health and can be used long-term if required.
- Glutamine is involved in more metabolic processes than any other amino acid. The GIT is the greatest user of glutamine in the body, so glutamine supports digestive and gastrointestinal health and function. Glutamine is essential for normal intestinal barrier function due to its ability to preserve the integrity of the mucosal intestinal lining. Glutamine is an important fuel source for rapidly proliferating cells of the immune system, making a significant contribution to GALT health and supporting healthy immune system function. Glutamine supports healthy gastrointestinal immune function. It is important for secretory IgA, an immune marker which functions primarily by preventing the attachment of bacteria to the mucosal cells of the GIT. Prolonged, strenuous exercise depletes plasma glutamine concentrations.
- Zinc supports healthy digestive and gastrointestinal function, and immune system health. Zinc is an essential component of various digestive enzymes and helps to increase mucin production, a component of mucus, which acts as a lubricant to help protect the GIT lining from irritants.
See Gut Care.