Evaluation of Different Delivery Vehicles on the Digestion and Absorption of Lutein using a Lymph Fistula Rat Model

Abstract

Lutein delivered through breast milk is better absorbed by infants than lutein delivered in infant formula. We wish to better understand the possible absorption differences of lutein in breast milk versus infant formula by determining its bioavailability after gastric administration and to investigate whether the intestinal absorption of lutein can be improved by using new delivery vehicles. In STUDY ONE, we compared, under similar experimental conditions, the intestinal uptake, and the lymphatic and portal transport of lutein in conscious lymph fistula rats. Four groups of rats (n = 8–10/group) were randomized to receive via the gastric tube increasing doses (10 mg/kg, 20 mg/kg, 40 mg/kg, 80 mg/kg) of 20% lutein in safflower oil (SO) suspension to assess whether there was a saturable level of lutein that can be absorbed from the gastrointestinal tract. Aliquots of hourly portal blood and lymph were taken for lutein analysis. The dose response study showed that 20 mg/kg lutein was the saturable level of lymphatic lutein absorption with no lutein detected in portal circulation at any dosage level. In STUDY TWO, we randomized five groups of rats (n = 4–9/group) to receive 20 mg/kg lutein from either lutein in SO or from lutein in four different mono‐diglyceride oils (MDG). Gastric infusion of lutein suspended in MDG (20 mg/kg) significantly improved (71% – 211%; p<0.05) lymphatic lutein output 2–6 hours after lipid feeding versus lutein in SO. We conclude that a mixture of MDG helps solubilize lutein and facilitate gastrointestinal micelle formation thus improving lymphatic lutein absorption compared to triglyceride oils.Support or Funding InformationDK059630, Abbott Nutrition ZA34B