Identification of Genetic Polymorphisms Associated with Interindividual Variability of Vitamin A Concentration in Adipose Tissue of Healthy Male Adults.

Background: Adipose tissue vitamin A (VA), that is, mainly retinol (RET) and its esters, comes from preformed VA and proVA carotenoids present in our food. Adipose tissue VA acts as hormonal cue maintaining essential aspects of adipocyte biology, which includes fat mobilization and catabolism, energy balance, and glucose homeostasis, and it is thus of particular interest to study its determinants, including genetic ones.

Objectives: This study aimed to identify genetic variations associated with adipose tissue VA concentration.

Characterization of the interindividual variability of lutein and zeaxanthin concentrations in the adipose tissue of healthy male adults and identification of combinations of genetic variants associated with it.

Lutein (L) and zeaxanthin (Z) are involved in visual function and could prevent age-related macular degeneration and chronic diseases and improve cognitive performances. Adipose tissue is the main storage site for these xanthophylls (Xanth). The factors affecting their concentrations in this tissue remain poorly understood but in animal models, genetic variations in apolipoprotein E and β-carotene oxygenase 2 have been associated with adipose tissue L concentration.

Validation of Knock-Out Caco-2 TC7 Cells as Models of Enterocytes of Patients with Familial Genetic Hypobetalipoproteinemias.

Abetalipoproteinemia (FHBL-SD1) and chylomicron retention disease (FHBL-SD3) are rare recessive disorders of lipoprotein metabolism due to mutations in and genes, respectively, which lead to defective chylomicron formation and secretion. This results in lipid and fat-soluble vitamin malabsorption, which induces severe neuro-ophthalmic complications. Currently, treatment combines a low-fat diet with high-dose vitamin A and E supplementation but still fails in normalizing serum vitamin E levels and providing complete ophthalmic protection.

The Interindividual Variability of Phytofluene Bioavailability is Associated with a Combination of Single Nucleotide Polymorphisms.

Scope: Phytofluene is a colorless carotenoid with potential health benefits that displays a higher bioavailability compared to carotenoids such as lutein, β-carotene or lycopene. Several studies suggest its bioavailability displays an elevated interindividual variability. The aim of this work is to investigate whether a combination of SNPs is associated with this variability.

Vitamin A deficiency during the perinatal period induces changes in vitamin A metabolism in the offspring. The regulation of intestinal vitamin A metabolism via ISX occurs only in male rats severely vitamin A-deficient.

Purpose: 1) To test the hypothesis of the existence of a perinatal vitamin A (VA) programming of VA metabolism and to better understand the intestinal regulation of VA metabolism.

Methods: Offspring from rats reared on a control (C) or a VA-deficient (D) diet from 6 weeks before mating until offspring weaning, i.e.

Bioaccessibility and uptake by Caco-2 cells of carotenoids from cereal-based products enriched with butternut squash (Cucurbita moschata L.).

Enriching cereals-based products with bioactive compounds is a valuable strategy to improve product quality. We studied carotenoid bioaccessibility and intestinal uptake from a pumpkin-enriched porridge, cookies and sponge cakes by using in vitro digestion coupled with Caco-2 cell uptake. Among the carotenoids recovered in different products, α-carotene was the most important abundant one.

β-Carotene Bioavailability and Conversion Efficiency Are Significantly Affected by Sex in Rats: First Observation Suggesting a Possible Hormetic Regulation of Vitamin A Metabolism in Female Rats.

Scope: To study the effect of variation in dietary vitamin A (VA) content on its hepatic and intestinal metabolism.

Methods And Results: Adult female and male rats are fed with diets containing 400, 2300, or 9858 IU kg VA for 31-33 weeks. VA concentrations are measured in plasma and liver.

Vitamin A Deficiency during the Perinatal Period and First Weeks of Life Modifies Vitamin A and Lipid Postprandial Metabolism in Both Female and Male Young Rats.

Scope: The effect of vitamin A deficiency on vitamin A and lipid postprandial metabolism in young rats is addressed, considering the effect of sex.

Methods And Results: Sprague-Dawley rats are fed either 400 UI.kg vitamin A diet (vitamin A-deficient (VAD) diet) or 2300 UI.

The Complex ABCG5/ABCG8 Regulates Vitamin D Absorption Rate and Contributes to its Efflux from the Intestine.

Scope: Most people are vitamin D insufficient around the world. Vitamin D intestinal absorption should thus be optimized. The role of the ATP-binging cassette G5/G8 (ABCG5/G8) heterodimer in vitamin D intestinal efflux is investigated.

Comparison of α-Tocopherol, α-Tocopherol Acetate, and α-Tocopheryl Polyethylene Glycol Succinate 1000 Absorption by Caco-2 TC7 Intestinal Cells.

(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells.

P-glycoprotein (ABCB1) is involved in vitamin K efflux.

ABCB1 (P-glycoprotein/MDR1) is a multidrug efflux transporter that has previously been involved in cholesterol and vitamin D metabolism. Our aim was to explore whether ABCB1 is also involved in vitamin K efflux. Vitamin K apical efflux was significantly decreased in presence of ABCB1 inhibitor in Caco-2 cells (-20.

A Combination of Single Nucleotide Polymorphisms is Associated with the Interindividual Variability of Cholesterol Bioavailability in Healthy Adult Males.

Scope: Cholesterol bioavailability displays a high interindividual variability, partly due to genetic factors. Existing studies have focused on single nucleotide polymorphisms (SNPs) analyzed individually, which only explained a minor fraction of the variability of this complex phenotype. The aim is to identify a combination of SNPs associated with a significant part of the variability in cholesterol bioavailability.

The Effect of an Iron Supplement on Lycopene Metabolism and Absorption During Digestion in Healthy Humans.

Scope: To investigate the formation and absorption of lycopene (LYC) metabolites in the human upper gastrointestinal lumen, in the absence and presence of iron.

Methods: Healthy males (n = 7) consumed test meals that deliver ≈22 mg LYC + ≈0.3 mg apo-lycopenals from oleoresin without (-FeSO ) and with ferrous sulfate (160 mg, +FeSO ).

Comparison of the bioavailability and intestinal absorption sites of phytoene, phytofluene, lycopene and β-carotene.

The mechanisms of main tomato carotenes (phytoene, phytofluene, lycopene and β-carotene) intestinal absorption are still only partly understood. We thus compared carotene bioavailability in mice after gavage with carotene-rich oil-in-water emulsions. We also determined each carotene absorption profile along the duodenal-ileal axis of the intestine to identify their respective absorption sites and compared these profiles with the gene expression sites of their identified transporters, i.

The Presence of Pulses within a Meal can Alter Fat-Soluble Vitamin Bioavailability.

Scope: It is widely advised to increase pulse consumption. However, pulses are rich in molecules displaying lipid-lowering properties, including fibers, phytates, saponins, and tannins. The effects of pulses on fat-soluble vitamin bioavailability were thus explored.

Lipodystrophy-like features after total body irradiation among survivors of childhood acute leukemia.

Background/objective: The number of long-term survivors of childhood acute leukemia (AL) is substantially growing. These patients are at high risk for metabolic syndrome (MS), especially those who received total body irradiation (TBI). The consequences of children's irradiation on adipose tissue (AT) development in adulthood are currently unknown.

Nutritional Composition and Bioactive Content of Legumes: Characterization of Pulses Frequently Consumed in France and Effect of the Cooking Method.

Pulses display nutritional benefits and are recommended in sustainable diets. Indeed, they are rich in proteins and fibers, and can contain variable amounts of micronutrients. However, pulses also contain bioactive compounds such as phytates, saponins, or polyphenols/tannins that can exhibit ambivalent nutritional properties depending on their amount in the diet.

β-Cyclodextrin Does not Alter the Bioaccessibility and the Uptake by Caco-2 Cells of Olive By-Product Phenolic Compounds.

Alperujo-a two-phase olive mill waste that is composed of olive vegetation water and solid skin, pulp, and seed fragments - is a highly valuable olive by-product due to its high content in phenolic compounds. In this study, we assessed whether β-cyclodextrin (β-CD), which is used to extract and protect alpejuro phenolic compounds (hydroxytyrosol--glucoside, tyrosol, caffeic, and -coumaric acids) could impact on their bioaccessibility (i.e.

Production of asymmetric oxidative metabolites of [13C]-β-carotene during digestion in the gastrointestinal lumen of healthy men.

Background: Asymmetric β-apo-carotenoids (nonvitamin A-active metabolites) of provitamin A carotenoids have been observed in humans, but no study has investigated their formation during digestion.

Objective: The aim of this study was to follow the formation and absorption of asymmetric β-apo-carotenoids during digestion.

Design: Healthy men were intragastrically and intraduodenally intubated, and randomly assigned to consume a lipid-rich control meal (n = 3) or a lipid-rich test meal containing 20 mg [13C-10]-β-carotene (n = 7).

Comparison of the Micellar Incorporation and the Intestinal Cell Uptake of Cholecalciferol, 25-Hydroxycholecalciferol and 1-α-Hydroxycholecalciferol.

In the context of the global prevalence of vitamin D insufficiency, we compared two key determinants of the bioavailability of 3 vitamin D forms with significant biopotencies: cholecalciferol, 25-hydroxycholecalciferol and 1-α-hydroxycholecalciferol. To this aim, we studied their incorporation into synthetic mixed micelles and their uptake by intestinal cells in culture. Our results show that 1-α-hydroxycholecalciferol was significantly more solubilized into mixed micelles compared to the other forms (1.

A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Cholecalciferol Bioavailability in Healthy Men.

Background: Most people require dietary vitamin D to achieve the recommended concentration of 25-hydroxyvitamin D [25(OH)D] in the blood. However, the response to vitamin D supplementation is highly variable among individuals.

Objective: We assessed whether the variability in cholecalciferol bioavailability was associated with single-nucleotide polymorphisms (SNPs) in candidate genes.

Form of phytosterols and food matrix in which they are incorporated modulate their incorporation into mixed micelles and impact cholesterol micellarization.

Scope: The ability of different plant sterols/stanols (PS) mixtures, which differed in the degree of B-ring saturation and aliphatic side chain structure and saturation, to reduce cholesterol (CH) micellarization was explored.

Methods And Results: Experiments were performed using an in vitro digestion model, synthetic mixed micelles, and pure porcine pancreatic lipases. Sterols were measured by GC-FID.

A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Dietary β-Carotene Bioavailability in Healthy Men.

Background: The bioavailability of β-carotene, the main dietary provitamin A carotenoid, varies among individuals. It is not known whether this variability can affect long-term β-carotene, and hence vitamin A, status.

Objectives: We hypothesized that variations in genes involved in β-carotene absorption and postprandial metabolism could at least partially explain the high interindividual variability in β-carotene bioavailability.

Micellar lipid composition affects micelle interaction with class B scavenger receptor extracellular loops.

Scavenger receptors (SRs) like cluster determinant 36 (CD36) and SR class B type I (SR-BI) play a debated role in lipid transport across the intestinal brush border membrane. We used surface plasmon resonance to analyze real-time interactions between the extracellular protein loops and various ligands ranging from single lipid molecules to mixed micelles. Micelles mimicking physiological structures were necessary for optimal binding to both the extracellular loop of CD36 (lCD36) and the extracellular loop of SR-BI (lSR-BI).