iThei mdcdaelcinfd o c elllllrlllll tiThcl elThhlThscd mmshblkdho c dhpExciting advances in autoimmunity have recently been made by Italian-
American researcher Alessio Fasano, MD. Dr. Fasano and his colleagues
suggest the following three factors need to be present for autoimmunity
to develop:
1) Genetic predisposition2) Exposure to antigen (trigger)3) Intestinal permeabilityTogether, the intestinal permeability and triggers cause an immune sys-
tem imbalance that results in the body no longer recognizing itself from
a foreign invader.1,2
How Is Increased Intestinal Permeability Connected to
Autoimmune Disorders?
Spanning the surface area of a tennis court, your intestinal tract has the
largest concentration of immune cells and the same number of neurons
as your spinal cord.
Researchers have found that in addition to digesting and absorbing nu-
trients, the intestine is also responsible for keeping potentially harmful
substances from our environment out of our bodies. The intestinal wall,
in particular, has recently been credited with enabling the body to distin-
guish itself from foreign antigens.
When the intestinal wall becomes permeable, the body loses its ability
to recognize benign substances such as our own cells and the foods we
eat, instead treating them as though they were foreign invaders such as
bacteria and viruses.
Zonulin is a recently discovered human protein that reversibly increases
intestinal permeability. This protein is measured in excessive amounts in
individuals with autoimmune conditions such as rheumatoid arthritis,
Hashimoto’s, multiple sclerosis, type 1 diabetes, and celiac disease (see
the Gut chapter for more details).1,2
How Do Triggers Work?
Let’s use iodine as our sample trigger.
When iodine enters the cell, TPO—the enzyme that oxidizes iodide to
the reactive iodine—is released to allow the iodine to attach to tyrosine
residues in thyroglobulin to form thyroid hormones. (Refer to Chapter
2 for more details.)^3