TUDCA is a bile acid derivative that occurs naturally in the body. Like many compounds in your body, TUDCA is made through a microbial process.
Firstly, bile salts are released into your intestines through the liver bile duct. Microbes in your large intestine then metabolize the bile salts into ursodeoxycholic acid (UDCA). Next, it gets conjugated to taurine (an amino acid) in order to create TUDCA. This whole process happens naturally in your body and is supported when you have a healthy amount of bile salts.
A healthy person produces very small amounts of TUDCA, recycling about 95% of their bile salts via enterohepatic circulation (the process that occurs when bile is absorbed through the intestines and returned to the liver via the hepatic portal vein). However, poor diet, decreased liver function, and certain medications can impair this process.*
Although humans only make small amounts of TUDCA, this bile salt influences many bodily functions, from the brain to kidneys function to eye health and more, which is why TUDCA supplementation can be beneficial.