Search

International audience; Purpose1) 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.MethodsOffspring from rats reared on a control (C) or a VA-deficient (D) diet from 6 weeks before mating until offspring weaning, i.e., 7 weeks after mating, were themselves reared on a C or D diet for 19 weeks, resulting in the following groups: C–C (parents fed C—offspring fed C), D-C, C-D and D-D. VA concentrations were measured in plasma and liver. β-Carotene bioavailability and its intestinal conversion rate to VA, as well as vitamin D and E bioavailability, were assessed after gavages with these vitamins. Expression of genes involved in VA metabolism and transport was measured in intestine and liver.ResultsC–D and D–D had no detectable retinyl esters in their liver. Retinolemia, hepatic retinol concentrations and postprandial plasma retinol response to β-carotene gavage were higher in D–C than in C–C. Intestinal expression of Isx was abolished in C–D and D–D and this was concomitant with a higher expression of Bco1, Scarb1, Cd36 and Lrat in males receiving a D diet as compared to those receiving a C diet. β-Carotene, vitamin D and E bio-availabilities were lower in offspring receiving a D diet as compared to those receiving a C diet.ConclusionA VA-deficient diet during the perinatal period modifies the metabolism of this vitamin in the offspring. Isx-mediated regulation of Bco1 and Scarb1 expression exists only in males severely deficient in this vitamin. Severe VA deficiency impairs β-carotene and vitamin D and E bioavailability.

International audience; 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, alpha-carotene was the most important abundant one. However, lutein displayed a significantly higher bioaccessibility compared to alpha-carotene and 0-carotene in baked products (up to 10.28% compared to 1.22% and 0.88%, respectively). alpha-Carotene was the only carotenoid recovered in Caco-2 cells after micelle incubation. Cookie micelles led to the highest percentage of alpha-carotene cell uptake (2.33% and 1.38% for cookies with butter and cookies with vegetable oil, respectively) compared to the other baked products, followed by dry pumpkin puree micelles (1.31%). Overall, our data show that both bioaccessiblity and cell uptake of carotenoids from cereal-based products are variable and highly depend on food formulation and structure.

International audience; Some bioactive compounds found in pulses (phytates, saponins, tannins) display antinutritional properties and interfere with fat-soluble vitamin bioavailability (i.e., bioaccessibility and intestinal uptake). As canned chickpeas are consumed widely, our aim was to optimize the chickpea canning process and assess whether this optimization influences fat-soluble vitamin bioavailability. Different conditions during soaking and blanching were studied, as was a step involving prior germination. Proteins, lipids, fibers, vitamin E, lutein, 5-methyl-tetrahydro-folate, magnesium, iron, phytates, saponins and tannins were quantified. Bioaccessibility and intestinal uptake of vitamin D and K were assessed using in vitro digestion and Caco-2 cells, respectively. Significant reductions of phytate, saponin and tannin contents (− 16 to − 44%), but also of folate content (up to − 97%) were observed under optimized canning conditions compared with the control. However, bioaccessibility and cellular uptake of vitamin D and K remained unaffected after in vitro digestion of test meals containing control or optimized canned chickpeas.

International audience; (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. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p \textless 0.001); and (iii) significantly lower with the TPGS form (p \textless 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.

International audience; 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. Methods and Results Both cholecalciferol and 25-hydroxycholecalciferol apical effluxes are increased by ABCG5/G8 overexpression in human Griptite cells. Mice deficient in ABCG5/G8 at the intestinal level (I-Abcg5/g8(-/-) mice) display an accumulation of cholecalciferol in plasma in females and in liver in males compared to control animals. I-Abcg5/g8(-)(/)(-) mice display a delay in cholecalciferol postprandial response after gavage compared with controls. 25-Hydroxycholecalciferol transfer from plasma to lumen is observed in vivo in intestine-perfused mice, and the lack of intestinal ABCG5/G8 complex induces a decrease in this efflux, while vitamin D bile excretion remains unchanged. Conclusion Overall, it is showed for the first time that the ABCG5/G8 heterodimer regulates the kinetics of absorption of dietary vitamin D by contributing to its efflux back to the lumen, and that it also participates in vitamin D transintestinal efflux.

International audience; Scope: The specific effect of the food matrix structure on fat-soluble micronutrient bioavailability is only partly understood. Evaluating fat-soluble micronutrient bioavailability after consumption of foods displaying similar composition but different structure is aimed at. Methods and results: Twelve healthy subjects are enrolled in a randomized, open label, crossover postprandial trial. Four different model foods are tested: custard, pudding, sponge cake, and biscuit. Vitamin D 3 , lutein, and triglyceride chylomicron responses, evaluated as postprandial areas under the curve, are then assayed. Custard triglyceride response is higher than pudding and biscuit responses (up to +122.7%, p < 0.0001). Sponge cake vitamin D 3 response is higher than biscuit response (+26.6%, p = 0.047). No difference between the model foods are observed regarding lutein responses. Triglyceride responses peak at 3 h for all conditions, while vitamin D 3 and lutein peaks are delayed by 1 h with the biscuit matrix compared to other model foods. Conclusion: Food structure can significantly impact on triglyceride and vitamin D 3 bioavailability in terms of absorbed amounts and/or maximum absorption time. The data highlight positive correlations between triglyceride, vitamin D, and lutein nutrient responses. These results are of particular interest to develop functional foods for population subgroups such as the elderly.

Rethinking food systems from production to consumption, in order to provide better nutritional inputs at lower environmental cost, is a priority challenge for a sustainable future. Pulses present benefits that may improve the sustainability of our systems and diets, such as their ability to restore soils in nitrogen and their high contents in proteins, fibers and minerals. However, pulses also contain several bioactive compounds such as phytates or tannins that can negatively affect mineral absorption. Additionally, we recently showed in the laboratory that these bioactives, together with fibers and saponins, could negatively impact fat-soluble vitamin bioavailability. The objective of this study was thus to follow up vitamin D (as a model of fat-soluble vitamin) and iron (as a model of mineral) transfer to the aqueous phase of the bolus during digestion of meal containing or not pulses. To this aim, we performed in vitrodigestion using tests meals made of beef (as a model of meat) and/or semolina (as a model of cereals) and/or chickpeas (as a model of pulses). To identify the compounds responsible for the observed effects, we also performed in vitrodigestion using test meals made of potatoes supplemented or not in fibers, phytates, tannins and saponines. Vitamin D bioaccessibility and iron solubility were expressed as the ratio of vitamin D or iron recovered in the aqueous phase of the digestion on the total amount of vitamin D or iron recovered in the whole digesta, at the end of the digestion.Our results showed that the presence of chickpeas within a meal induced a significant decrease of both vitamin D bioaccessibility (up to -56%, p < 0.05) and iron solubility (up to -28%, p < 0.05) compared to meals containing only meat and/or semolina. However, this effect was largely compensated for vitamin D by the fact that this vitamin was less stable (loss > 50%, p < 0.05) during the digestion of meal containing meat compared to meals containing only plant-based foods (i.e. semolina and chickpeas). Among the different bioactives, tannins appear to be the most deleterious regarding iron solubility, while both phytates and tannins were responsible for a decreased in vitamin D bioaccessibility.Our results confirm that in some conditions, the presence of pulses within a meal can be deleterious regarding vitamin D and iron bioavailability. These data thus encourage research to propose dietary and technological solutions to tackle pulse negative effects on micronutrient bioavailability.

International audience; 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 (− 20.4%; p < 0.05) and increased in Griptite cells overexpressing ABCB1 (+40.7%; p < 0.05). In vivo, the vitamin K postprandial response was higher in male Abcb1 − /− mice after gavage compared to control animals (+115%; p < 0.05), but was unchanged in female mice. Finally, a vitamin K transintestinal efflux and a biliary vitamin K efflux were observed, but the specific involvement of ABCB1 could not be confirmed in these pathways. Overall, we showed for the first time that ABCB1 is involved in enterocyte vitamin K efflux in both cell and mouse models and regulates vitamin K absorption in mice. Recently, the multidrug membrane transporter ABCB1 (Sharom, 2011) has been identified to contribute to the intestinal transport of vitamin D (Margier et al., 2019

International audience; 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(-1) vitamin A diet (vitamin A-deficient (VAD) diet) or 2300 UI.kg(-1) vitamin A (control diet), before being mated. Mothers receive the same VAD or control diet during gestation and lactation. Offspring receive the same diet than mothers until 8 weeks of age. VAD diet-fed female and male offspring display a severe vitamin A deficiency with no body weight or glucose tolerance defects. Fasting plasma triglyceride concentrations are decreased in VAD diet-fed animals compared to controls (p < 0.05). Retinyl ester postprandial responses after vitamin A gavage, expressed as area under the curves, are not different in VAD diet-fed and control animals, although retinyl ester postprandial peak is significantly delayed (p < 0.05) in VAD diet-fed rats. Lipids also accumulate in the distal part of the intestine after gavage and [1-C-13]-oleate postprandial response is decreased in VAD diet-fed males. Conclusion Vitamin A deficiency modulates both vitamin A absorption rate and lipid postprandial metabolism, which can partly explain the altered fasting lipid status observed in VAD diet-fed offspring.

International audience; In this study, we evaluated vitamin D and mineral (iron, zinc, magnesium) transfer to the bolus aqueous phase during the digestion of meals with/without pulses. We performed in vitro digestions using test meals made either of i) beef and/or semolina and/or chickpeas, or of ii) potatoes supplemented or not with fibers, phytates, tannins and saponins. Chickpea presence led to a decrease in vitamin D bioaccessibility (-56%, p < 0.05) and mineral solubility (-28% for iron, p < 0.05) compared with meals with beef and/or semolina only. This effect was largely compensated for vitamin D by the fact that this vitamin was more stable during digestion of meals based on plant foods only than of meals with beef. Tannins were the most deleterious compounds for iron solubility, while phytates and tannins decreased vitamin D bioaccessibility. Agronomical or technical solutions to selectively decrease the amount in pulses of compounds that affect micronutrient bioavailability should be further explored.

International audience; 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. We thus explored the effects of pulses on fat‐soluble vitamin bioavailability. Methods : We assessed vitamin A (β‐carotene and retinyl‐palmitate), vitamin E (α‐tocopherol), vitamin D (cholecalciferol) and vitamin K (phylloquinone) bioaccessibility, i.e. micellarization after in vitro digestion of meals containing either potatoes (control), household‐cooked or canned pulses. The obtained mixed micelles were delivered to Caco‐2 cells to evaluate vitamin uptake. We then specifically assessed the impact of fibers, phytates, saponins and tannins on both phylloquinone (used as a model vitamin) bioaccessibility and uptake. Results : The presence of pulses significantly decreased both vitamin bioaccessibility (up to ‐65% for β‐carotene, ‐69% for retinyl‐palmitate, ‐45% for cholecalciferol, ‐53% for α‐tocopherol and ‐67% for phylloquinone) and uptake (‐40% for retinyl‐palmitate, ‐67% for cholecalciferol, ‐50% for α‐tocopherol and ‐57% for phylloquinone). Effects on bioaccessibility, but not on uptake, were dependent on pulse cooking method. Phylloquinone bioaccessibility was specifically impacted by saponins, tannins and fibers while its uptake was impacted by saponins, fibers and phytates. Conclusion : Pulses can alter fat‐soluble micronutrient bioavailability. Pulses should thus be cooked appropriately and consumed within micronutrient‐rich meals.

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.e. SR-BI and CD36. Our data show that phytofluene presented a significantly higher bioavailability compared to lycopene and β-carotene (areas under the curve of 0.76 ± 0.09 vs. 0.30 ± 0.05, 0.09 ± 0.05 and 0.08 ± 0.01 μmol/L·h for phytofluene, phytoene, lycopene and β-carotene, respectively). β-Carotene was mostly converted in the proximal and median intestine. Phytoene and phytofluene accumulation tended to be more important in the distal intestine, which did not correlate with the proximal expression of both Scarb1 and CD36. Overall, these results highlight the high bioavailability of phytofluene. Junta de Andalucía CAROTINCO-P12-AGR-1287

International audience; The aim was to enhance provitamin A carotenoid (proVA CAR) concentrations and bioaccessibility in carrots by manipulating post-harvest factors. To that end, we assessed the effects of Ultraviolet-C light, pulsed light, storage temperature, and storage duration. We also measured CAR bioaccessibility by using an in vitro model. Pulsed light, but not Ultraviolet-C, treatment increased proVA CAR concentrations in the cortex tissue (p

This work was supported by an INRA Priority Action of the "Alimentation Humaine" department (2013-2015). Marielle Margier received a doctoral fellowship (2015-2018) from Region PACA in partnership with the Centre Technique de Conservation des Produits Alimentaires (CTCPA, Avignon); Scope: Food matrix is generally believed to alter carotenoid bioavailability, but its effect on xanthophylls is usually limited. This study thus aims to decipher the digestion-absorption process of lutein in the presence or not of a food matrix.Methods: Lutein transfer to gastric-like lipid droplets or artificial mixed micelles was assessed when lutein was added to test meals either as a pure molecule ((all-E)-lutein) or in canned spinach ((Z) + (all-E)-lutein). The obtained mixed micelles were delivered to Caco-2 cells to evaluate lutein uptake. Finally postprandial plasma lutein responses were compared in minipigs after the two test meals.Results: Lutein transfer to gastric-like lipid droplets and to mixed micelles was higher when lutein was added in spinach than when it was added as pure lutein (+614% and +147%, respectively, p < 0.05). Conversely, lutein uptake was less effective when micellar lutein was from a meal containing spinach than from a meal containing its pure form (-55%, p < 0.05). In minipigs, postprandial lutein response was delayed with spinach but not significantly different after the two test meals.Conclusion: Opposite effects at the micellarization and intestinal cell uptake steps explain the lack of effect of spinach matrix on lutein bioavailability.

The authors are very grateful to the physician and nurses of the Human Nutrition Research Centre of Auvergne and to Patrice Reiling for their technical assistance; International audience; Lycopene (LYC) bioavailability is relatively low and highly variable, because of the influence of several factors. Recent in vitro data have suggested that dietary Ca can impair LYC micellarisation, but there is no evidence whether this can lead to decreased LYC absorption efficiency in humans. Our objective was to assess whether a nutritional dose of Ca impairs dietary LYC bioavailability and to study the mechanism(s) involved. First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement. Plasma LYC concentration was measured at regular time intervals over 7 h postprandially. In a second approach, an in vitro digestion model was used to assess the effect of increasing Ca doses on LYC micellarisation and on the size and zeta potential of the mixed micelles produced during digestion of a complex food matrix. LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal. In vitro, Ca affected neither LYC micellarisation nor mixed micelle size but it decreased the absolute value of their charge by 39 %. In conclusion, a nutritional dose of Ca can impair dietary LYC bioavailability in healthy humans. This inhibition could be due to the fact that Ca diminishes the electrical charge of micelles. These results call for a thorough assessment of the effects of Ca, or other divalent minerals, on the bioavailability of other carotenoids and lipophilic micronutrients.