Leaky Guts and Autoimmune Diseases

Over the past 20 years, autoimmune diseasesyndrome" which is associated with the autoimmune
research has discovered a related set of factorsantibody reaction and the disorders which develop.
which link all autoimmune diseases.Alessio Fasano, M.D. directs the Mucosal Biology
One of these factors is intestinal permeability. In aResearch Center and the Center for Celiac Research
normal human gut, the cells lining the intestinal wall actat the University of Maryland School of Medicine.
as a barrier that allows only properly digested fats,Much of his research focuses on the relationship
proteins, and starches to pass through and enter thebetween intestinal permeability and autoimmune
bloodstream. There are several methods of nutrientdiseases.
transport. The first two, diffusion, and a mechanismHe and his research team have discovered a
called active transport move vitamins, minerals andmolecule, which they named zonulin. Zonulin is
normal nutritive molecules through the cells on theinvolved in the regulation of intestinal cell wall
wall of the intestine.permeability. Dr. Fasano's research has linked zonulin
However, substances can also pass beyond theto the pathogenesis of a series of autoimmune
intestinal wall through the spaces between thediseases, including type 1-diabetes, celiac disease, and
intestinal cells. Normally, these spaces are sealedmultiple sclerosis. Dr. Fasano writes:
tightly, but when the intestinal lining is irritated by"Discovery of zonulin prompted us to search the
some external trigger, the junctions between themedical literature for human disorders characterized
cells loosen and begin to "leak" larger foreign proteinsby increased intestinal permeability...much to my
from the intestines into the blood. The immunesurprise.. many autoimmune diseases - among them,
system reacts by creating aggressive antibody cellsceliac disease, type 1 diabetes, multiple sclerosis,
to attack these foreign invaders.rheumatoid arthritis, and inflammatory bowel diseases
In addition, the leaked molecules may act as "mimics"- all have as a common denominator aberrant
of normal body proteins. In a process calledintestinal permeability".
"molecular mimicry", parts of these foreign proteinsIn other words, all of these autoimmune diseases
may look chemically similar to self-proteins found instart or are worsened by a leaky gut. Increasing the
other areas of the body. When activated to attacklevels of zonulin increases the permeability of the
the foreign proteins, the antibodies mistake the similarintestinal wall.
self-proteins as foreign, and attack them as well.Other factors include a genetic predisposition toward
As the intestinal wall is compromised by the externalthe disease which develops, but the autoimmune
trigger and becomes increasingly irritated, it becomesresponse seems to be triggered by gut permeability
more permeable or "leaky" and a condition known asand the leakage of foreign proteins which mimic self
"leaky gut syndrome" develops. It is this "leaky gutproteins into the blood stream.