In aged laying hens, adding taurine to the diet at 0.05%, 0.1%, or 0.2% reduces the activity of genes involved in cholesterol production and increases the activity of genes involved in cholesterol...
Mechanism
Synthesis from 1 study
Taurine tells the liver to stop making cholesterol and start getting rid of it by sending it out in bile or turning it into stored fat. This reduces the amount of cholesterol that ends up in egg yolks.
Most probable mechanism
Taurine tells liver cells to stop making cholesterol and start removing it by sending it out in bile or turning it into stored fat, which lowers the amount of cholesterol that ends up in egg yolks.
Taurine enters hepatocytes and reduces the activity of the transcription factor SREBP2, which controls genes involved in cholesterol production.
Lower SREBP2 activity decreases the expression of HMGCR, the enzyme that performs the first committed step in cholesterol biosynthesis.
Reduced HMGCR activity lowers the conversion of HMG-CoA to mevalonate, decreasing the production of new cholesterol molecules.
Taurine increases the expression of ABCG5, a transporter that moves cholesterol from liver cells into bile for excretion.
Taurine increases the expression of ACAT2, which converts free cholesterol into cholesteryl esters for storage in lipid droplets or packaging into lipoproteins.
Cholesteryl esters and bile-excreted cholesterol reduce the pool of free cholesterol available for incorporation into very low-density lipoproteins.
Lower circulating cholesterol reduces the amount delivered to the ovary during yolk formation, decreasing cholesterol deposition in egg yolks.
Less supported by current evidence, but not ruled out
At higher doses, taurine increases the liver's ability to turn cholesterol into bile acids, which are then excreted, further reducing cholesterol levels.
Taurine increases the expression of CYP7A1, the enzyme that initiates the conversion of cholesterol into bile acids.
Increased bile acid synthesis removes cholesterol from the liver and interrupts its recycling through the enterohepatic circulation.
Reduced hepatic cholesterol availability limits its transport to the ovary and deposition into egg yolks.
Evidence from Studies
Supporting (1)
Community contributions welcome
Effects of dietary taurine supplementation on polyunsaturated fatty acids, cholesterol, and egg quality of egg of hens
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.