Taurine is an interesting and unique amino acid-like compound that humans are poor at synthesizing. We are thereby reliant on dietary intake of taurine for its broad range of effects.
Taurine, along with glycine, is required for bile to do its job in digesting fats. Bile acids such as cholic acid and chenodeoxycholic acid are produced by the liver, where they are then “conjugated’ with taurine or glycine to form taurocholate, glycocholate, and a number of other bile “salts” that are secreted into the gastrointestinal (GI) tract that then help digest dietary fats. Poor intake of taurine and/or failure to deconjugate bile salts in the small bowel (for recovery of taurine) have been associated with a number of adverse health effects, especially a drop in HDL cholesterol values (that can be profound), ileitis/colitis, while disruptions in bowel flora associated with reduced blood and intestinal levels of taurine have been shown to increase potential for coronary disease, and–incredibly–for intracranial aneurysms.
Increased intestinal levels of taurine have been demonstrated to:
- Reduce the populations of Proteobacteria in the GI tract–Proteobacteria are largely the species of small intestinal bacterial overgrowth, SIBO. Increased taurine also reduces endotoxemia (i.e., serum levels of lipopolysaccharide, LPS).
- Increase intestinal populations of Lachnospiracea and Ruminococcaceae, beneficial species
- Improve resistance to infection–an effect mediated via changes in bile acid metabolism and the GI microbiome.
- Strengthen the integrity of the intestinal barrier–Some probiotic bacterial species, such as some species/strains of Collinsella and L. reuteri, express an enzyme called bile salt hydrolase that, in turn, deconjugates bile salts, releasing free taurine that strengthens the intestinal barrier tight junctions.
I am not arguing that taurine needs to be supplemented, though this has been proven to be a benign agent with a number of modest benefits of supplementation including reduction of blood pressure, improved exercise performance and accelerated recovery after strenuous exercise, and possibly reduced potential for complications of diabetes. But the fact that taurine can only be obtained naturally by consuming animal products (along with vitamin B12, zinc, EPA + DHA, etc.) is yet another argument in favor of Homo sapiens being reliant on consumption of animal products. And, to fully address taurine status, you need to also address bowel flora composition. Emerging science in the microbiome suggests that taurine has a bidirectional effect: it influences the species of microbes inhabiting the GI tract, while microbes influence taurine production (and release from bile salts).
At the very least, we therefore should be mindful of our taurine intake. Here is the taurine content of various animal-sourced foods (from Eilertsen 2012) per 100 gram serving (3.5 ounces):
Beef 36 mg
Chicken, light meat 18 mg
Chicken, dark meat 169 mg
Turkey, light meat. 30 mg
Turkey, dark meat 306 mg
Pork 61 mg
Lamb 45 mg
Veal 40 mg
Cod 120 mg
Salmon 94 mg
Mackerel 78 mg
Scallops 827 mg
Oysters 396 mg
Claims 520 mg
Organ meats, especially heart, are also rich in taurine. The high taurine content of fish and shellfish is especially interesting. Research into the benefits of omega-3 fatty acids, EPA + DHA, have suggested that consumption of fish and shellfish is superior to consumption of fish oil supplements, suggesting that there is something in addition to omega-3 fatty acids that is beneficial. Could it be taurine?
Is there an ideal intake of taurine? And what is the ideal intake after improvements have been made in microbiome composition such as eradication of SIBO? This tangle of questions has not yet been unraveled. But we need to be aware of taurine and its microbiome connection.