Definition

Malabsorption is a condition where the body is unable to absorb nutrition from consumed food. This condition affects millions of people worldwide and has various causes. For example, individuals sensitive to gluten (a protein found in grains) are more commonly found in Europe or North America but are rarely observed in Asia, the Caribbean, and Africa. In addition to disorders affecting the absorption of specific nutrients, malabsorption can be caused by infections, disruptions to the normal flora in the digestive tract, or disorders affecting the mucous layer of the digestive tract.

Causes

Food absorption occurs in three stages. The first stage involves the mechanical breakdown of food through chewing and stomach muscle movements and the chemical breakdown by digestive enzymes. In the second stage, the nutrients broken down by enzymes are absorbed by the cells lining the walls of the digestive tract. Finally, these nutrients are distributed throughout the body via the blood and lymphatic systems.

However, various damages to the digestive system can impair nutrient absorption. This can affect the absorption of multiple nutrients, including fats, proteins, carbohydrates, vitamins, and minerals.

In the initial stage, abnormalities that can interfere with nutrient absorption include disorders of intestinal movement and enzyme secretion. Disorders of intestinal movement may result in the rapid mixing and breakdown of food, leading to suboptimal nutrient absorption. On the other hand, enzyme secretion disorders can be attributed to conditions such as pancreatitis, pancreatic cancer, cystic fibrosis (which thickens and sticks mucus excessively, hindering food movement), liver and bile duct diseases, and imbalances in gut bacteria. Additionally, enzyme secretion disorders can stem from congenital conditions resulting in a lack of specific enzymes.

Moving to the second stage, which involves the absorption of nutrients into the cells lining the digestive tract, abnormalities can arise from cell damage caused by autoimmune conditions (where the immune system attacks the body), bacterial infections, parasite infections, worm infections (more prevalent in individuals with HIV), chemotherapy, radiation therapy in cancer patients, and surgical procedures.

In the third stage, where nutrients are distributed throughout the body, disruptions can occur due to conditions like blockages in the lymphatic system. These blockages may be caused by congenital factors, cancer, or tuberculosis, which can impede the absorption of proteins and fats.

Risk factor

The risk factors for malabsorption can include:

• Family history of hereditary diseases
• Autoimmune diseases targeting digestive cells
• Surgical history involving the intestine
• HIV/AIDS infection
• Infections of the digestive tract are caused by bacteria, viruses, parasites, fungi, or worms
• Congestive heart failure leads to fluid accumulation throughout the body, including the intestines
• History of cancer
• Previous radiation therapy
• Previous chemotherapy
• Tuberculosis

Symptoms

The symptoms of malabsorption depend on the cause and the specific nutrients that cannot be absorbed. However, the most common symptom is diarrhea. Here are the symptoms associated with malabsorption of specific nutrients:

• Fat Malabsorption

Symptoms include diarrhea accompanied by pale and foul-smelling stools. Stools may be difficult to flush as they float. Malabsorption can lead to weakness and significant weight loss.

• Macronutrients (Carbohydrates, Fats, Proteins)

Symptoms include bloating, abdominal cramps, and smelly gas due to bacterial fermentation.

• Protein Malabsorption

Causes swelling throughout the body, especially in the feet, due to fluid accumulation outside blood vessels.

• Iron and Vitamin B12 Malabsorption

Anemia symptoms such as paleness and fatigue may occur, as these substances are essential for normal red blood cell production.

• Vitamin K Malabsorption

Leads to blood clotting disorders with symptoms like unexplained bruising, black stool, or blood in the urine.

• Vitamin D and Calcium Malabsorption

Causes disorders in bone mass, making bones brittle. Malabsorption of blood electrolytes like calcium and magnesium may lead to involuntary muscle twitching.

• Other vitamin malabsorption 

Lack of vitamins such as B5 and D may cause overall weakness. Deficiency in vitamin B1 can damage peripheral nerves. Lack of vitamin B12 can result in loss of vibration and position sensation. Lack of vitamin B7 can lead to seizures. Vitamin A malabsorption can result in night blindness and vision disturbances.

Diagnosis

If there are suspicions of malabsorption, a comprehensive physical examination can be conducted to address specific symptoms and rule out other potential causes. For example, blood pressure may be assessed to detect orthostatic hypotension, a condition where blood pressure significantly drops upon changing from a sitting to a standing position. Body composition is examined to identify any loss of fat tissue under the skin and evaluate muscle atrophy. Edema, or swelling, is assessed in the stomach and feet. Skin examination helps identify signs of paleness, bruising, or other skin conditions. Neurological examination involves evaluating the strength of movement in various body parts and checking for signs of peripheral nerve damage, particularly at the ends of the feet and hands. This thorough examination aids in determining the presence of malabsorption and assists in excluding other potential contributing factors.

Laboratory exams for malabsorption depend on the specific symptoms exhibited. If anemia is suggested, a complete blood test can help narrow down potential causes. Additional blood tests, such as serum iron, vitamin B12, and folic acid levels, can aid in diagnosis. In cases of unexplained bruising, examinations related to blood clotting, including those for vitamin K malabsorption, may be conducted. Tests for blood electrolytes like sodium, potassium, chloride, calcium, and magnesium can be instrumental in diagnosing disorders related to these substances. Examinations for fat, enzymes, and antibodies can also contribute to the diagnostic process. Tissue samples may be taken for laboratory examination to identify any narrowing of intestinal villi.

For specific infections or conditions, additional tests may be performed. For instance, HIV/AIDS examinations can determine if this condition is the underlying cause. Acid-fast bacilli tests and rapid molecular tests can be conducted to identify tuberculosis.

Imaging studies can provide insights into potential abnormalities in the intestine, including issues related to motility, thinning of the protective layer, or intestinal shape disorders. An examination involving the insertion of fluid into the anus, observed through X-ray, can be employed. Additionally, CT scans may be conducted to detect abnormalities in the intestine and pancreas, which produce various digestive enzymes. These diagnostic approaches contribute to a comprehensive understanding of the potential causes and manifestations of malabsorption.

Management

The treatment for malabsorption depends on the specific substance lacking and the underlying cause. The primary goal is to address nutritional deficiencies and, if possible, manage the root cause. Daily calorie intake must meet the body's requirements, and supplements such as calcium, magnesium, iron, and vitamins may be necessary. Collaborating with a nutritionist or specialist doctor helps plan a tailored diet to address the condition.

For patients with fat malabsorption, choosing fats like medium-chain triglycerides (MCT) can help replace the fat intake. In cases of extensive intestinal inflammation, nutritional intake may be administered intravenously.

Celiac disease, exacerbated by gluten, can be managed by adopting a gluten-free diet. Lactose-intolerant patients can avoid dairy products to alleviate symptoms.

When pancreatic abnormalities are present, enzyme supplements may aid in the breakdown of food substances. If an imbalance of bacteria in the intestine is the issue, antibiotics may be the treatment choice. In the case of bowel inflammation, anti-inflammatory drugs may be prescribed. Tailored treatments aim to address both nutritional deficiencies and the specific causes of malabsorption for effective management.

Complications

Complications arising from malabsorption are intricately linked to the specific nutrients that fail to be adequately absorbed. Malnutrition is a primary concern, as the deficiency in essential nutrients can contribute to a wide array of abnormalities throughout the body. Anemia may result from insufficient absorption of iron, vitamin B12, or folic acid, leading to a decreased number of red blood cells. Blood clotting problems may emerge due to malabsorption of vitamin K. Vision problems, including night blindness, can occur with inadequate absorption of vitamin A.

Brittle bones and bone density issues may manifest when vitamin D and calcium are not absorbed properly. Electrolyte imbalances, stemming from the malabsorption of key elements like sodium, potassium, chloride, calcium, and magnesium, can contribute to heart rhythm problems. Peripheral nerve damage may occur due to deficiencies in specific vitamins such as B1 and B12. Additionally, prolonged fatigue is a common consequence, given the insufficient absorption of nutrients crucial for energy production.

Prevention

Preventing malnutrition is not always feasible, especially in cases of chronic conditions such as celiac disease, cystic fibrosis, cancer, tuberculosis, and inflammatory bowel disease (IBD). However, for certain conditions like an imbalance of bacteria in the intestine, preventive measures can include the use of prescribed antibiotics. Infections, a potential cause of malabsorption, can be minimized by consuming cooked food and practicing proper hand hygiene before eating.

HIV/AIDS transmission can be prevented through responsible behaviors, such as abstaining from illegal drugs, practicing safe sex, and using condoms during sexual activities. Additionally, reducing the risk of pancreatitis can be achieved by discontinuing alcohol consumption and smoking. 

When to see a doctor?

Seek medical attention promptly if you or others exhibit signs or symptoms of malnutrition. The symptoms may vary depending on the specific nutrients being malabsorbed, but they can also be indicative of more serious underlying conditions such as cancer, tuberculosis, HIV/AIDS, and others. Consulting with a doctor is crucial for a thorough evaluation. In some cases, you may be referred to a nutritionist or Nutrition Specialist Doctor to determine appropriate nutritional therapy tailored to your condition. This therapy may be complemented by addressing the underlying causes of malnutrition if necessary.