Gut microbiota-mediated pharmacokinetics of ginseng saponins

Orally administered ginsengs come in contact with the gut microbiota and their hydrophilic constituents, such as ginsenosides, are metabolized to hydrophobic compounds by gastric juice and gut microbiota: protopanxadiol-type ginsenosides are mainly transformed into compound K and ginsenoside Rh2, protopanaxatriol-type ginsenosides are to ginsenoside Rh1 and protopanaxatriol, and ocotillol-type ginsenosides to ocotillol. Although this metabolizing activity varies between individuals, the metabolism of ginsenosides to compound K by gut microbiota in individuals treated with ginseng is proportional to the area under the blood concentration curve (AUC) for compound K in their blood samples.