Learn About Intestinal Malabsorption Syndrome

The intestinal malabsorption syndrome refers to a set of disorders derived from an alteration in the absorption of nutrients in the digestive tract. This alteration can be due to different causes: inflammatory, genetic, infectious …

Depending on its origin, it can be global or specific to a certain nutrient. Once the mechanism that produces it has been diagnosed, the necessary treatment will be addressed. Let’s see more below.

Digestion physiology

Digestion is a process that consists of breaking down the food we eat into simpler components and absorbing them in the intestine. 

This process begins in the mouth, with chewing. Food breaks into smaller pieces and mixes with saliva; thus they form the food bolus. In addition, fats (lipids) and carbohydrates begin to be broken down by the action of salivary enzymes.

The food bolus passes into the esophagus and reaches the stomach. In this organ, hydrochloric acid and enzymes are released that digest proteins and fats into simpler compounds.

The mass that has formed in the stomach is called chyme, and it passes into the small intestine. In this section of the digestive tract, the pancreas and liver release pancreatic juices and bile, respectively.

• Pancreatic juice contains many enzymes to complete digestion, such as trypsin and amylase. Trypsin activates other enzymes that participate in the digestion of proteins. Meanwhile, amylase is responsible for the digestion of carbohydrates. It is also essential in the digestion of fats.

• The bile produced by the liver contains bile salts, essential for the emulsion of fats. This process consists of forming small aggregates of lipids called micelles , so that they can be absorbed in the small intestine.

It is in this section when the “true digestion” takes place. Once the simple molecules that come from the decomposition of food have been obtained, they are absorbed by the intestinal cells so that they pass into the blood.

Cells in the small intestine are called enterocytes , and they have molecules and enzymes that allow minerals, lipids, vitamins, carbohydrates, and proteins to pass into the blood. 90% of absorption takes place in the small intestine.

Waste products pass into the large intestine, where the formation of stool takes place, which is expelled through the anus. Also in this intestinal tract some nutrients are absorbed, mainly minerals and water.

Therefore, digestion is a very complex process, regulated by multiple organs and glands. A failure in any of the involved parts can lead to intestinal malabsorption syndrome.

As the MSD Manual indicates, the seriousness of this is that “malabsorption causes deficiencies of all nutrients or selective deficiencies of proteins, fats, sugars, vitamins or minerals”.

Fat malabsorption

Once the steps of lipid digestion have been explained, lipid malabsorption can be due to different causes:

• Pancreatic insufficiency: pancreatic juices are necessary to assimilate fats. If its production is insufficient, there may be a fat malabsorption. This is what can happen in patients with pancreatitis.

• Bile salt deficiency: bile salts can be decreased by liver pathologies or obstructions of the bile ducts, which connect the liver with the small intestine so that the bile reaches the digestive tract. If there are no bile salts or they do not reach the intestine, the fats are not absorbed.

• Alteration of the intestinal mucosa : inflammation of the intestinal mucosa can alter the digestion of nutrients. This is what happens in intestinal infections or inflammatory diseases such as Crohn’s disease.

• Gastrectomies : These are surgical interventions that consist of removing a damaged portion of the stomach. One of its consequences is to alter digestion, so that an alteration of the digestive functions of the stomach can cause a syndrome of intestinal malabsorption.

Fat malabsorption clinic

A lipid malabsorption could cause the following symptoms:

• Steatorrhea: it is the presence of fat in the stool as it is not absorbed. It can be seen by seeing that the stool is lighter and floats in the toilet.

• Weight loss: since lipids are a source of energy and constitute an important energy reserve.

• Symptoms derived from the lack of absorption of fat-soluble vitamins. These vitamins need the same mechanisms as lipids, so they are not absorbed either. The fat-soluble vitamins are A, D, E, K, and F.

Protein malabsorption

Triggers  are similar to those described for lipids:

• Gastrectomies.

• Pancreatic Insufficiency:  Trypsin is necessary to break down proteins into smaller compounds.

• Lack of bile salts:  These are necessary for the proper functioning of trypsin. In this case, intestinal protein malabsorption will be less.

Protein malabsorption clinic

Proteins are a fundamental component in muscle, so if their absorption fails, there will be a significant decrease in muscle mass. As a consequence, weight loss can also occur.

In severe cases, a lack of protein can cause a decrease in albumin (hypoalbuminemia), an essential protein in the blood. If this decreases, there is a significant alteration of circulatory function that can cause fluid to accumulate in the legs and they swell; Technically, this is called edema.

Carbohydrate malabsorption

In this case, the malabsorption is usually specific, as a consequence of an alteration of the intestinal mucosa. Enterocytes contain enzymes necessary for the final stretch of carbohydrate digestion; If these enzymes do not work, the absorption of carbohydrates is insufficient.

The most characteristic form is lactose intolerance. The same happens if there is an inflammation of the intestinal mucosa due to infections or inflammatory diseases, such as celiac disease.

Carbohydrate Malabsorption Clinic

Carbohydrates are the main energy source, especially to obtain energy quickly. A lack of its absorption will produce a loss of weight. In addition, the presence of unabsorbed carbohydrates irritates the intestinal mucosa, causing watery diarrhea.

Although less common, there may also be situations in which intestinal malabsorption syndrome is due to a lack of absorption of water, minerals, and vitamins. 

In all cases, it is necessary to inquire about eating habits, since some deficits derive from insufficient intake.  Likewise, general intestinal problems, such as infections or surgical interventions, must be ruled out.