What Causes Bile Acid Malabsorption? Symptoms, Diagnosis & Treatment

What Can Cause Bile Acid Malabsorption?

There are various causes that lead to bile acid malabsorption, ranging from diseases affecting your small intestine to surgical interventions that affect the intestine’s ability to absorb bile. Sometimes, bile acid malabsorption occurs due to unknown causes, referred to as idiopathic bile acid malabsorption.

Primary Causes of Bile Acid Malabsorption

1. Gallbladder Removal (Cholecystectomy)

Some individuals need to have their gallbladder surgically removed due to reasons like gallstones, infections, or other causes, which results in bile continuously dripping into the small intestine instead of being stored and released in a controlled manner by the gallbladder. This leads to bile acids being present excessively in the small intestine, causing BAM.

2. Crohn’s Disease 

Crohn’s disease is a condition that causes inflammation of the digestive tract, most commonly the small and large intestines. When Crohn’s disease affects the ileum, the last part of the small intestine, which is responsible for the resorption of bile acids, it can lead to inflammation and damage to the tissues and cause bile acid malabsorption.

3. Short Bowel Syndrome 

Short bowel syndrome occurs when a significant portion of the small intestine is removed surgically (due to structural abnormalities or conditions like Crohn’s disease), is short due to birth defects, or is damaged, reducing the area available for bile acid resorption. This can also lead to bile acid malabsorption.

4. Ileal Diseases or Damage 

The ileum (the last part of the small intestine) is the primary site of bile reabsorption. Specialised transport proteins such as ASBT and IBABP found in the ileum facilitate bile resorption. Any condition or disease affecting the ileum, such as infections, damage due to radiation or medicines, surgeries, or bacterial overgrowth, can result in BAM.

5. Celiac Disease

Celiac disease is an autoimmune disorder that causes inflammation and damage to the intestinal villi, which are tiny finger-like projections that increase the surface area. This impairs both the absorption of nutrients and bile acids. 

6. Bile Acid Synthesis Disorders 

Some people are born with defects or errors in bile acid synthesis, which results in the production of abnormal bile acids that cannot be easily absorbed by the small intestine. This can also contribute to BAM.

Secondary Causes of Bile Acid Malabsorption 

Other reasons for bile acid malabsorption are: 

1. Use of Antibiotics 

When you take antibiotics often or over a prolonged period of time, you not only kill the harmful microbes, but you also kill the beneficial ones, which will disrupt your gut microbiome (the community of microbes that live in your gut) that helps to reabsorb bile acid. This causes bile acid malabsorption. 

2. Too Much Fatty Foods 

When you eat too much fat and oily foods, for example, fried foods or processed foods, your body releases more and more bile into your small intestine. Eventually, you may release more bile than your body can reabsorb, and this can also cause BAM. 

3. Liver Disease 

Bile acids are made in the liver to aid in digestion. Diseases of the liver, such as cirrhosis or hepatitis, can also affect the production of bile, the absorption of bile acids, and their circulation, causing bile acid malabsorption.

Symptoms of Bile Acid Malabsorption

“Bile acid malabsorption has been a known cause of diarrhoea for years, but many people with this condition still don’t get diagnosed or treated properly.” - Dr Naveen Chandran V, Chief Medical Officer, Nirva Health.

Symptoms of bile acid malabsorption can vary from mild to severe and differ from person to person. Here are some of its common symptoms:

1. Chronic Diarrhoea 

Abnormally high amounts of bile acids present in the colon can lead to poor stool formation, increased secretion of water into the colon, and increased frequency of defecation, ultimately leading to the classic symptom or sign of persistent watery diarrhoea. 

2. Abdominal Pain 

Excess bile acid in the colon can also irritate or damage the epithelial lining of the gut and cause abdominal pain or cramping. 

3. Flatulence (Gas) and Abdominal Distension 

If bile acids remain undigested in the colon, they will induce the secretion of more fluids and electrolytes and change the normal digestive processes to produce gas, a feeling of fullness in the abdomen, and belching.

4. Weight Loss

Bile acid malabsorption causes impaired fat digestion and absorption, lowering your overall calorie absorption and eventually leading to deficiencies of fat-soluble vitamins. This may result in unintended weight loss.

5. Steatorrhea

Steatorrhoea refers to increased fat excretion in the stool, resulting in bulky, pale, and foul-smelling stools. Poor resorption of bile acids from the ileum results in impaired fat digestion, which results in fat-mixed stools.

6. Fatigue

Bile acid malabsorption leads to chronic diarrhoea and poor nutrient absorption in the intestines, leading to deficiencies and affecting your energy levels. The resulting malnutrition can lead to impaired body functions and fatigue.

Diagnosis of Bile Acid Malabsorption

Often, bile acid malabsorption is misinterpreted as other intestinal conditions like irritable bowel syndrome (IBS) or chronic diarrhoea. That is why getting a precise diagnosis of bile acid malabsorption is critical for providing effective management. 

Some common diagnostic tests for BAM are: 

1. SeHCAT Test 

The SeHCAT (selenium homocholic acid taurine) test is a diagnostic test for bile acid malabsorption. How is the test done? Your healthcare professional will ask you to swallow a capsule containing some synthetic bile acid and a small amount of radioactive material (75 selenium). The body absorbs this bile acid as if it were naturally occurring bile acid, and a gamma camera detects how much bile acid was absorbed. 

2. Stool Tests 

This test assesses the amount of bile acids passed in the stool. Furthermore, a stool test will indicate the presence of undigested fat in the stool (steatorrhoea), which is a sign of bile acid malabsorption.

3. Blood Tests

There are also specific blood tests that assist in diagnosing bile acid malabsorption. These blood tests assess the levels of bile acid synthesis markers. Elevated levels of certain markers may indicate BAM or another gut issue.

Blood tests can also help detect or rule out underlying conditions like liver disease, infections, or nutritional deficiencies. 

4. Imaging and Endoscopy

If you already have an underlying issue that affects your intestines, such as Crohn’s disease or other diseases that affect the ileum, doctors may suspect BAM to occur secondary to these. Imaging tests such as CT or MRI  may be necessary for a proper evaluation in such cases.

Treatment and Management of Bile Acid Malabsorption

Bile acid malabsorption has been recognised in medicine for decades, but its understanding and clinical significance have gained more attention in recent years. Because its broader effects on the body are still being actively explored, treatments for BAM are also evolving.

Can this condition be cured? Unfortunately, no. But its symptoms can be effectively managed with the right combination of medications and lifestyle adjustments, helping you lead a normal, symptom-free life.

How can bile acid malabsorption be managed? Here are some of the common treatments:

1. Bile Acid Sequestrants 

These are the main medications used to treat bile acid malabsorption. Bile acid sequestrants (e.g., cholestyramine and colesevelam) act by binding to bile acids in the intestine to form an insoluble complex that is then excreted in the stool. This prevents irritation of the gut wall and diarrhoea. 

2. Diet Modifications 

Making these easy yet effective changes to your diet can help you manage BAM:

Low-Fat Diet:

• Consuming a diet low in fat can reduce the burden on your digestive system and reduce the amount of bile being released into the small intestine.

Consuming Smaller Meals More Often:

• Smaller meals result in bile being released in controlled quantities instead of a large bile dump, thus reducing excessive bile acids in the intestines. Smaller meals are also easier on the gut and reduce the chances of diarrhoea.

Increased Fibre Intake:

• Increasing your fibre intake, especially soluble fibres, helps by binding to the excess bile in the colon and promoting its excretion, thus preventing it from becoming concentrated in the intestines and causing damage.

3. Probiotics

“The main property of probiotics relating to bile acid levels is its cholesterol-lowering effect.” – The influence of probiotics on bile acids in diseases and ageing, ScienceDirect.

Certain probiotic strains aid in fat digestion, apart from balancing your gut microbiome and supporting your overall health. Some probiotic strains, like Lactobacillus and Bifidobacterium, even break down bile acids (bile salt hydrolase activity) and enhance the excretion of bile acids in faeces.

4. Supportive Treatments

For individuals with severe bile acid malabsorption symptoms or other underlying conditions like Crohn’s disease or celiac disease, other supportive treatments, such as corticosteroids, immunosuppressant medications, and other specific treatments, may be necessary.

Wrapping Up

Bile acid malabsorption is a hidden culprit behind digestive issues, especially chronic diarrhoea, often overlooked and misdiagnosed. But the good news? Recent breakthroughs in treatment and management now empower those affected to live normal, comfortable lives. 

If natural remedies or over-the-counter medicine cannot effectively handle your digestive issues, you should go see a medical professional for a diagnosis and treatment. Need help dealing with your gut issues? Contact team Nirva’s trained practitioners who can support you in your journey to long-term gut health.