enterodiol

Enterodiol is a mammalian lignan metabolite that acts as a phytoestrogen. It is produced in the human gut by the action of intestinal bacteria on dietary lignans and can be converted further to enterolactone. The principal dietary sources of lignans that give rise to enterodiol include flaxseed, sesame, whole grains, legumes, and various fruits and vegetables.

Metabolism and occurrence: plant lignans ingested with food are metabolized by gut microbiota to enterodiol, which is absorbed and circulates in the bloodstream before being excreted in urine. The extent of enterodiol formation varies among individuals and is influenced by the composition of the intestinal microbiota. Enterodiol and its metabolite enterolactone are commonly measured as biomarkers of lignan exposure.

Biological activity: enterodiol exhibits estrogen-like activity, but with relatively low affinity for estrogen receptors compared with endogenous estrogens. It is considered a phytoestrogen that may modulate estrogen signaling in a tissue-specific manner. In addition to hormonal activity, lignan metabolites have been investigated for antioxidant, anti-inflammatory, and potential anticancer properties, though evidence from human studies remains inconclusive and inconsistent.

Health and dietary considerations: routine dietary intake of lignans contributes to circulating enterodiol levels. While observational studies have suggested associations between higher lignan exposure and certain health benefits, clinically meaningful effects on cancer risk or cardiovascular outcomes have not been firmly established. Individual effects may depend on gut microbiota composition and overall diet.

See also: phytoestrogen, lignans, enterolactone.