Bile Acids and Digestive Health: A Closer Look

Understanding Bile Acids: Their Role in Digestion

The Digestive Process: How Bile Acids Break Down Fats

Have you ever wondered what bile is and what does it do? Bile or gall is a greenish-yellow fluid that the liver makes to help your body break down fat from your food. Bile acids or bile salts are responsible for emulsifying or mixing the fats in the food. They break down the larger fat into smaller molecules, making it easier for digestive enzymes to break down the fat into fatty acids for easier absorption in the small intestine. When bile acids are done with their job, they are reabsorbed and recycled by the body. Bile also helps with eliminating waste products from your body via feces.

The Liver and Gallbladder: The Source of Bile Acids

Bile is produced by the liver and stored in the gallbladder, where it is later secreted into the small intestine during a meal to help break down fat in the diet. Your gallbladder can hold approximately 30-80 mL of fluid at a time and acts as a storage unit for bile until needed. Besides bile acids, bile also contains cholesterol, water, phospholipids, bilirubin, and electrolytes such as potassium and sodium. There are other metals like copper present. 

Below is a list of bile acids that are present in bile:

• Cholic acid

• Chenodeoxycholic acid

• Glycochenodeoxycholic acid

• Ursodeoxycholic acid

• Taurochenodeoxycholic acid

Bile Acid Malabsorption: A Common Digestive Disorder

Bile acid malabsorption occurs when bile acids are not working properly in the small intestine and are unable to be absorbed and passed to the large intestine. This causes the colon to secrete extra water, leading to diarrhea. Bile acid malabsorption can be caused by other conditions, such as colitis, Crohn’s disease, HIV enteritis, post-infectious diarrhea, and exocrine pancreatic insufficiency. Certain medical treatments, such as chemotherapy, surgery, and diabetic medications, can also induce bile acid malabsorption.  

Symptoms of Bile Acid Malabsorption: Diarrhea and Abdominal Pain

As previously mentioned, watery, frequent diarrhea is a tell-tale sign that you might have bile acid malabsorption. You might also experience bowel urgency or difficulty getting to the toilet on time. Other symptoms entail abdominal cramping and pain, gas, and indigestion. Over time if left untreated and undiagnosed, bile acid malabsorption can lead to dehydration from excess fluid and electrolyte loss, fatigue/weakness, dizziness, nausea, headaches, and weight loss, leading to malnutrition. If left unchecked, severe bile acid malabsorption can result in bile acid deficiency, meaning that your body will not have enough bile acids to produce more bile, and you can develop vitamin ADEK deficiencies.

The Link Between Bile Acid Malabsorption and IBS

Several studies have identified links between IBS and bile acid malabsorption, and it is currently estimated that approximately 25-33% of people with IBS also have bile acid malabsorption. It has been suggested that individuals with bile acid malabsorption have increased intestinal permeability, similar to those diagnosed with IBS. Alterations in the gut microbiome may also be present as microbiota directly impact an individual's bile acid profile, which may result in bile acid malabsorption being a key player in the pathogenesis of IBS-D. There is also research underway to identify several biomarkers for bile acid malabsorption in people with IBS-D which could help lead to a more effective treatment.

Managing Bile Acid Malabsorption: Dietary and Lifestyle Strategies

The Low FODMAP Diet: A Potential Solution

Current dietary recommendations for managing bile acid malabsorption include following a low-fat diet. However, new research has shown that a Low FODMAP diet may help reduce gas and excess fluid in the gut, which can, in turn, impact the amount of bile acids in the gut.  

Probiotics and Prebiotics: Supporting Gut Health

Both prebiotics and probiotics may help reduce bile acid malabsorption. Specifically, prebiotics can reduce bile acid excretion, which could potentially be linked to their impact on feeding a healthy gut microbiome. Similarly, probiotics may also help; they can produce bile salt hydrolase enzymes that break down bile acids and reduce the amount of bile acids that reach the large intestine.

Medication: Treating Symptoms and Underlying Conditions

In addition to dietary interventions, medications such as bile acid sequestrants may be needed in some instances to help manage bile acid malabsorption. Furthermore, treating underlying conditions like IBD, celiac disease, exocrine pancreatic insufficiency, and IBS is key to managing the symptoms of bile acid malabsorption. Reducing inflammation can help the body work properly and may limit other problems, such as bile acid malabsorption.  

If you suspect that you have bile acid malabsorption or have uncontrolled diarrhea, talk with your healthcare provider to rule out potential causes and find strategies to manage symptoms.

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