Enhanced Lacto-Tri-Peptide Bio-Availability by Co-Ingestion of Macronutrients

Some food-derived peptides possess bioactive properties, and may affect health positively. For example, the C-terminal lacto-tri-peptides Ile-Pro-Pro (IPP), Leu-Pro-Pro (LPP) and Val-Pro-Pro (VPP) (together named here XPP) are described to lower blood pressure. The bioactivity depends on their availability at the site of action. Quantitative trans-organ availability/kinetic measurements will provide more insight in C-terminal tri-peptides behavior in the body. We hypothesize that the composition of the meal will modify their systemic availability. We studied trans-organ XPP fluxes in catheterized pigs (25 kg; n=10) to determine systemic and portal availability, as well as renal and hepatic uptake of a water-based single dose of synthetic XPP and a XPP containing protein matrix (casein hydrolyte, CasH). In a second experiment (n=10), we compared the CasH-containing protein matrix with a CasH-containing meal matrix and the modifying effects of macronutrients in a meal on the availability (high carbohydrates, low quality protein, high fat, and fiber). Portal availability of synthetic XPP was 0.08 ± 0.01% of intake and increased when a protein matrix was present (respectively 3.1, 1.8 and 83 times for IPP, LPP and VPP). Difference between individual XPP was probably due to release from longer peptides. CasH prolonged portal bioavailability with 18 min (absorption half-life, synthetic XPP: 15 ± 2 min, CasH: 33 ± 3 min, p

部分食物源肽（food-derived peptides）具有生物活性，可对机体健康产生积极影响。例如，C端（C-terminal）乳源三肽Ile-Pro-Pro（IPP）、Leu-Pro-Pro（LPP）以及Val-Pro-Pro（VPP）（本文中将其统称为XPP）被报道具有降血压功效。其生物活性取决于作用部位的生物利用度（availability）。定量跨器官（trans-organ）生物利用度/动力学检测（kinetic measurements）可更深入地揭示C端三肽在体内的行为规律。本研究假设，膳食组成会改变这些肽的全身生物利用度。
本研究以10头体重25kg的插管猪为实验对象，检测跨器官XPP通量，以评估单次水基合成XPP及含XPP的蛋白基质（酪蛋白水解物，casein hydrolyte, CasH）的全身与门静脉生物利用度（portal availability），以及肾脏摄取（renal uptake）和肝脏摄取（hepatic uptake）情况。在第二项实验（n=10）中，我们将含CasH的蛋白基质与含CasH的膳食基质进行对比，并探究膳食中宏量营养素（macronutrients）（高碳水化合物、低品质蛋白、高脂肪及膳食纤维）对生物利用度的调控作用。
合成XPP的门静脉生物利用度为摄入量的0.08 ± 0.01%，当添加蛋白基质后，该值显著提升（IPP、LPP、VPP分别提升3.1倍、1.8倍和83倍）。CasH可将门静脉生物利用时长延长18分钟（合成XPP的吸收半衰期（absorption half-life）为15 ± 2 min，CasH组为33 ± 3 min，p