Leaky gut syndrome is a term for increased intestinal permeability. The intestine is lined with a single layer of epithelial cells. In the small bowel these epithelial cells are called enterocytes. Enterocytes form the intestinal barrier.
The small intestine lining has projections called villi. The enterocytes of the small intestine have projections on their surfaces known as microvilli where digestive enzymes reside. Intestinal villi and microvilli dramatically increase the absorptive area of the gut. Damage to the enterocytes or their microvilli can affect digestion and absorption.
The enterocytes are joined to each other by tight junctions or zonula occludens that form a barrier to fluid and proteins. The tight juntions may open up the spaces between the cells, the paracellular space allowing movement of intestinal contents inside the body. Abnormally leaky tight junctions result in increase intestinal permeability or a leaky gut. This altered intestinal permeability or barrier function is implicated in several diseases, especially celiac disease and the inflammatory bowel diseases. We will continue to explore these concepts further so be sure to subscribe to the Food Doc blog for automatic updates.