In humans and most mammals, bile acids play a role in the metabolism of glucose and the transport and absorption of lipids (such as cholesterol and triglycerides), vitamins, and nutrients by allowing for emulsification (mixing) and absorption of fatty molecules that are consumed. More recently, bile acids have been discovered to influence the composition and quantity of the microorganisms in the gut microbiome. Bile acids also act as signalling molecules (like hormones) in the body, regulating important metabolic pathways and digestion.
While the majority of bile acids are recycled back to the liver, a small proportion of these bile acids enter the colon and interact with the gut microbiota. Primary bile acids, synthesized in the liver, are essential for the absorption of fat- and fat-soluble vitamins, as part of the digestive process. These primary bile acids are converted to secondary bile acids by gut bacteria, which have been shown to have benefits to health. This provides the rationale for exploring the use of a bile acid, in this case 7-keto lithocholic acid (7-KLCA), as a beneficial modulator of the gut microbiome, to help regulate metabolic and potentially other disease pathways.