What are bile acids and what does the body need them for?

Bile acids explained simply

The liver produces bile every day, which is stored and concentrated in the gallbladder. Its most important components are the bile acids, mainly cholic acid and chenodeoxycholic acid. When you eat a meal containing fat, the gut signals demand, the gallbladder contracts and releases bile into the small intestine.

What bile acids do in the gut

Fat and water do not mix. Bile acids work like washing-up liquid: they break large fat droplets into tiny ones that fat-digesting enzymes can attack. They then form small spheres together with the fat building blocks, the micelles. These also carry fat-soluble vitamins (A, D, E, K) to the intestinal wall.

Most bile acids are reabsorbed further down the gut and returned to the liver. This loop is called the enterohepatic circulation, and it runs several times per meal.

Bile acids and curcumin

Curcumin is strongly lipophilic, so it barely dissolves in water. This is where bile acids come in: when you take turmeric with a fatty meal, bile release into the small intestine is stimulated and curcumin can be enclosed in micelles and carried to the intestinal wall. Studies show that absorption is better with fat than without.

That explains why turmeric is traditionally used with oil, ghee or milk. The effect remains limited, though: even with fat, the powder produces only low blood levels, which is why bioavailability is a research topic of its own for curcumin.

According to studies, curcumin itself stimulates bile flow (a choleretic effect). That is one reason for caution in people with existing bile duct problems.

When this matters in everyday life

With a very low-fat meal, the gallbladder releases little bile. Fat-soluble compounds, which besides curcumin include vitamins A, D, E and K, are then absorbed less well. This is why many fat-soluble supplements are recommended to be taken with a meal containing some fat.

After removal of the gallbladder or with certain liver diseases, fat digestion can also be altered. If that applies to you, seek medical advice.

Frequently asked questions

Where are bile acids made? In the liver, from cholesterol. The gallbladder only stores and concentrates the bile.

What happens without a gallbladder? The liver then releases bile directly into the gut, but more evenly. Many people cope well, although fatty meals are sometimes tolerated less well.

Do bile acids have other roles? Yes, they also act as signalling molecules in metabolism, which is the subject of current research.