Christine Foutch is a practicing Holistic Physician in Rock Island, Illinois, specializing in Holistic Nutrition and Biomechanics. Holistic medicine is the art and the science of healing that addresses the whole person – body, mind, and spirit. The practice of holistic medicine integrates conventional and alternative therapies... more
The structure, as well as the surface area of the small intestine, make the process of nutrient absorption very efficient. To be very clear, nutrient absorption refers to the transfer of the nutrients into and out of the enterocytes. If you remember back my previous articles, you would know that the villi are made up of hundreds of the enterocytes, which are absorptive cells.
The villi are covered with thousands of the microvilli. The sweeping action of the Microvilli pulls and traps the nutrients towards the surface area of the enterocytes for the passage through the cell’s membrane.
However, the transfer of the nutrients from the lumen of the small intestine into the enterocytes is only the first step in nutrient absorption.
The extent to which a nutrient is to be absorbed is called bioavailability. The Bioavailability of a nutrient can be influenced by the physiological conditions, other dietary components, and certain medications. For example, the absorption of calcium or iron is dictated by the physiological needs of the body.
Generally, the body absorbs what it needs and excretes the rest within the feces. These steps can help in the prevention of toxicity.
For the nutrients to enter into the blood or the lymph, they must pass the basolateral membrane. This is the cellular membrane that is facing away from the lumen of the small intestine and towards the submucosa, which is just a layer of tissue that is between the innermost layer of the mucosa and the muscularis and responsible for the motility of the GI tract.
So, what am I getting at?
Diseases that affect the absorptive surface of the small intestines, including their enterocytes and their cellular membranes, will lead to nutritional deficiencies.
Let’s look at celiac disease. Celiac disease is a chronic autoimmune disease characterized by malabsorption and diarrhea brought on by the ingestion of food products containing gluten, a protein that is found in wheat, barley and rye.
The prevalence of celiac disease within the United States increased fourfold within the past three decades. Worldwide, celiac disease affects about 0.6% to 1% of the entire population.
Celiac disease is much more common in patients with type 1 diabetes mellitus and is associated with a greater risk of retinopathy and nephropathy within this population.
The occurrence rate is the highest during infancy and the first 36 months of life, after the introduction to foods containing gluten. There was also an increased incident rate within the 3rd decade, which is often associated with pregnancy and severe anemia during pregnancy, and then within the 7th decade.
There is a slight female predominance. However, the average age of diagnosis is within the 5th decade of life.
The risk of celiac disease is 5% to 10% in newborn children of parents with the disease, and nearly 20% in siblings. The bad news is that only about 10% to 15% of individuals with the disease have been diagnosed within the United States.
Weight loss, dyspepsia, which can also be called an upset tummy, short-stature, and failure to thrive is noted in children and infants. Weight-loss, fatigue and diarrhea are common in adults, but abdominal pain and vomiting are unusual. Pallor, which is a unhealthy pale appearance as a result from iron deficiency anemia. Atypical forms, meaning forms that are unusual, are being increasingly recognized.
So, what is really going on here? Well, with the progressive damage caused by the inflammatory response to the absorptive surface within the small intestine, this causes the cellular surfaces to thicken and the microvilli to flatten out.
This will alter the sweeping action ability of the microvilli, which is helping to pull and then trap the nutrients toward the surface area of the Enterocytes for the passage through the cellular membrane into the cell.
This scar tissue forms because of the macrophages and neutrophils, which are immune cells that play a role within the inflammatory response by releasing proteins and small molecule inflammatory mediators that control infections. These can, and will, damage the host tissues as well.
As a result, the nutrient absorption is impaired and people with celiac disease often experience diarrhea, weight loss and malnutrition.