Did you know that liver, our second largest organ, also plays a role in regulating our blood pressure? It has to do with bile acids, a substance that the liver cells make to help with digestion. Let’s dive in a little more to understand how it all works.

Bile acids

Bile acids are formed by the liver cells as the liver processes cholesterol. These bile acids combine with amino acids and are stored in the gall bladder. When we eat, food makes its way through the esophagus, stomach and intestines. When food reaches the intestine, it triggers activation of the gall bladder. Now, the bile acids (also called as natural detergents) release from the gall bladder into the intestine to help our body break down and absorb fats. This process is like using a dishwashing liquid to remove the grease on our utensils.

When the bile acids reach the intestines, gut microbiota (the microscopic organisms that live in our digestive system) remove the amino acids from the bile acids and converts primary bile acids into secondary bile acids. These secondary bile acids also help us digest fat, stop the growth of certain harmful bacteria and act as signaling molecules for various metabolic and immune functions. About 95% of the bile acids that our body produces are reabsorbed by our body and are sent back to the liver through our bloodstream.

Role of bile acids and microbiota in blood pressure

Bile acid pools in the body are also regulated by gut microbiota. The composition of gut microbiota is affected by factors such as our diet and use of antibiotics. These changes in bile acid and gut microbiota can influence our blood pressure.

Bile acids are not just tiny molecules that break down fat. They can also whisper instructions to other organs to regulate our blood pressure. Some bile acids activate signals through their receptors that “unlock” certain physiological functions. Bile acids act as keys and the receptors act like locks. When the key matches the lock, it opens the signaling pathways that can either lead to relaxation or constriction of the blood vessels and regulate blood pressure. The right key and lock combination may also influence vascular tone and kidney function, which help in blood pressure regulation too.

Why is this important?

Targeting the gut microbiota, bile acids and their receptors within the gut-liver axis could be a promising frontier in managing high blood pressure. Continuing this line of research could significantly enhance the existing studies exploring the integrative role of bile acids and gut microbiota in the regulation of blood pressure. Learning more about how bile acids and gut microbiota work together will add to the development of personalized treatment plans in treating hypertension in the near future.