ABSORPTION DISORDERS / MALABSORPTION SYNDROMES
The term absorption disorder does not refer to a specific disease but rather to diseases characterized by problems involving digestion or absorption of nutrients in the diet. These nutrients include: carbohydrates, fats, proteins, minerals and vitamins.
Digestion involves the breakdown of complex molecules to their simpler forms that can then be absorbed through the intestinal walls into the bloodstream for distribution to all cells within the body.
One of the many benefits associated with diabetes research is a better understanding of the central role of the intestine, the primary absorptive site, in glucose homeostasis (balance). Structural and or functional disorders of the intestinal tract may either increase or decrease the absorptive rate of glucose leading to major health issues or problems. Glucose absorption is a complex process involving, 1) the rate at which the stomach empties its chyme (the semifluid mass of partly digested food that is passed from the stomach into the small intestine); 2) the digestive process within the Gastro-Intestinal (GI) tract; 3) the ability of the cells lining the intestine to both identify and transport glucose molecules from its’ lumen (the cavity of a tubular organ) into the bloodstream.
Gastric emptying can be impacted by a variety of compounds. Certain antibiotics, like erythromycin accelerates stomach emptying while morphine slows the process. High sugar levels have been found to slow gastric emptying while insulin induced hypoglycemia speeds up the rate.
Disorders that interfere with the production or transport of digestive enzymes can prevent the breakdown of complex molecules to their simplest form thereby preventing transport across cell membranes. Fruit and vegetable carbohydrates require the assistance of the body’s microbes (biome) to digest them to simpler form accounting for the slower absorption and lower glycemic index of carbs from these nutritional sources.
Specialized receptors within the cells lining the intestine trigger both nerve and hormonal interactions fundamental to glucose homeostasis. A molecule of glucose, once sensed, can be actively transported across these cellular membranes to the blood stream where it is carried to all body cells. One of the roles of insulin is to reduce the rate of glucose absorption thereby maintaining glucose levels.
Most often absorption disorders results in a decreased ability to absorb nutrients (malabsorption). However, in the case of Hemochromatosis, involving iron, and Wilson’s disease, involving copper, the rate of mineral absorption actually increases.
COMMON MALABSORPTION DISORDERS include: celiac disease (intolerance to gluten); lactose intolerance caused by the lack of the enzyme lactase; tropical sprue thought to be due to intestinal lining damage; Whipple’s disease caused by a bacterial infection of the small intestinal lining and a variety of medical conditions including: scleroderma, cystic fibrosis, cancer within the GI tract, fibromyalgia, cirrhosis, Crohn’s disease, chronic pancreatitis ,short bowel syndrome and radiation therapy.
SYMPTOMS - Symptoms will depend on the type of nutrients being malabsorbed. General symptoms include: abdominal cramps, bloating, chronic diarrhea, hair losss, foul-smelling stool, floating and/or bloody stool, gas, loss of appetite, weight loss, nausea, and vomiting. Both vitamin (B12) deficiency and/or iron (Fe) deficiency, can lead to complications such as anemia, dehydration, bone loss, and malnutrition.
DIAGNOSIS - Diagnosis depends on the underlying cause for the condition. A patient’s history and family history of malabsorption syndromes, upper endoscopy, colonoscopy, barium x-rays may be employed.
Laboratory tests on blood, stool and urine along with a biopsy of the small intestinal lining are recommended.
TREATMENT - Damage to the GI tract can take as much as 1 to 2 years to resolve with proper treatment which can include medications, supplements, dietary restrictions, avoidance of alcohol and smoking. Nutrient and fluid replacement are the initial steps taken in treating malabsorption syndrome.