The Role of Intestinal Villi
Coating the inner wall of the small intestine are thousands of finger-like projections called villi. Just shy of 1 mm, these microscopic ‘nutrient sponges’ increase the surface area of the intestines 30-fold with a velvety texture, not unlike the soft nap of a plush towel. Inside each villi are blood vessels, known as capillaries, that absorb tiny food molecules broken down by the power of the stomach. Coating the outside of each villi are enzymes that further aid with digestion. The role of the villi is to send the pre-digested food molecules off to the rest of our body through the blood. Because of the villi’s rich blood supply and single-celled walls, this process is done with supreme efficiency if – and only if – they are in good working order.
The Role of Microvilli
Villi are covered with microvilli that serve the purpose of moving food through the digestive tract, similar to a “broom” of sorts for cleaning and aiding in motility. The microvilli are what give the surface of the villi a fuzzy appearance called the “brush border”, and contains enzymes which complete the digestion of carbohydrates and proteins in the small intestine. The microvilli further increase the already 30-fold surface area of the small intestine so nutrient absorption is enhanced by 60-fold!
The Destruction of Villi
A person with Celiac disease has less, or deficient villi, and so when they eat foods containing gluten, their immune system responds by damaging or destroying the villi. This means that the body of a person with Celiac disease is unable to absorb the necessary nutrients for good health. Without healthy villi, a person can easily become malnourished, no matter how much good food one eats.
Perhaps this sheds light on the real dangers of Celiac disease and why it is classified as both a disease of mal-absorption (where nutrients are not absorbed properly) and an abnormal immune reaction to gluten.