Tuesday, January 01, 2008
Leaky Gut Part 1-The intact gut lining
To help those who are reading my blog understand the role of the digestive tract in health and disease I am writing a series of short articles. First we will explore the basic anatomy and function of the gut so you can understand the role of food proteins, bacteria, yeast, medication and stress in leaky gut. The first concept to understand is that of the limited protective barrier provided by the single layer of intestinal cells.
A single layer of cells only lines our digestive tract. These cells are joined together by proteins that produce tight junctions in the intact gut. These tight junctions serve as a barrier as well as a normal site of entry. Surrounding these barrier cells are mobile immune cells that contribute to the primary immune defense of the gut.
The lining cells are types of epithelial cells. They are named by their location and function. In the small intestine or bowel these cells are called enterocytes. In the intestine these epithelial cells or enterocytes are positioned very close to each other, “shoulder to shoulder” if you will. Connecting them are protein “scaffoldings”. The connections produced “tight junctions” (TJ). The proteins forming the tight junctions include proteins called occludens (occlude the tight junctions) that are regulated by another set of proteins, primarily zonulin (the “zone regulator or foreman”).
This single cell lining of the digestive tract is part what is called the innate immune defense system. The cells form a barrier or wall protecting the inside of the human body. The intact gut lining is meant to protect us from potential harmful invaders or toxins such as bacteria, viruses, parasites, toxic yeast, chemical toxins and toxic food proteins. However, in many ways our gut, especially given all the insults we subject it to, is more like the border between the U.S. and Mexico. Our gut may have times where there large areas of potential entry of alien proteins into the body.
Patrolling on the outside of the gut wall are some defensive proteins or antibodies, primarily IgA. Under the surface are various immune fighter cells especially lymphocytes stationed as scouts. They can communicate with other cells to summon reinforcements for a battle. Typically, for example only 1-5 lymphocytes are deployed in a forward location in the tip of a villous in the small intestine.
Copyright © 2008, The Food Doc, LLC, All Rights Reserved.
Dr. Scot Michael Lewey
“Dr. Celiac, the food doc”
1699 Medical Center Point
Colorado Springs CO 80907