Absorption and Transit of Lutein and β-Carotene Supplements in the Mongolian Gerbil (Meriones unguiculatus)

Based on a previous carotenoid bioavailability study in Mongolian gerbils (Meriones unguiculatus), we hypothesized that gerbils preferentially accumulate β-carotene over lutein in the liver and lipoproteins. To monitor transit times of these carotenoids through the gastrointestinal tract and concentrations in various tissues and tissue contents, 0.1 μmol each of β-carotene and lutein were given separately as well as in combination to gerbils (n = 30). Contents of stomach, intestines, and ceca were collected at 1.5, 3, and 6 hours following the dose and analyzed for β-carotene and lutein. Mucosal scrapings, liver, and serum were also collected. When β-carotene and lutein were given in combination, 41 ± 11% (mean ± SD) β-carotene versus 20 ± 4.0% lutein were recovered in total from all tissues and tissue contents. At 3 hours, 45 ± 19% and 55 ± 2.8% of the β-carotene and lutein supplements, respectively, were recovered in the cecum when given separately. When given in combination, 59 ± 32% and 55 ± 25% of the β-carotene and lutein, respectively, were recovered in the cecum. Beta-carotene was up to 45-fold higher than lutein liver concentrations 6 hours after dosing. Gerbils are a useful model for β-carotene bioavailability studies as they absorb and store β-carotene. More studies are needed to determine whether significant extra-hepatic lutein storage occurs in gerbils.