Impact of pulses, starches and meat on vitamin D and K postprandial responses in mice.

In vitro experiments showed that i) phytates, tannins and saponins from pulses can alter vitamin D and K bioavailability and ii) meat decreased vitamin D bioaccessibility by impairing its stability during digestion. We aimed to confirm these results in vivo by force-feeding mice with emulsions containing either potatoes or semolina or chickpeas or meat. Vitamin D and K plasma responses decreased after a gavage with chickpeas or meat compared with potatoes (-62 % and -67 %, respectively for vitamin D, -40 % and -64 %, respectively for vitamin K; p < 0.05). Vitamin D and K intestinal contents were also reduced in mice force-fed with chickpeas or meat compared with potatoes (from -64 to -83 % and from -76 to -84 %, respectively for vitamin D and from -7 to -59 % and from -7 to -90 %, respectively for vitamin K; p < 0.05). The results confirm that chickpea and meat compounds can decrease vitamin D and K bioavailability.

Reduction of pulse "antinutritional" content by optimizing pulse canning process is insufficient to improve fat-soluble vitamin bioavailability.

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.

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 (-20.4%; 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.

Evaluation of vitamin D bioaccessibility and mineral solubility from test meals containing meat and/or cereals and/or pulses using in vitro digestion.

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.

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. 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.

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-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 [1-13 C]-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.

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. METHODS: Vitamin A (ß-carotene and retinyl palmitate), vitamin E (α-tocopherol), vitamin D (cholecalciferol), and vitamin K (phylloquinone) bioaccessibility was evaluated by assessing 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. The impact of fibers, phytates, saponins, and tannins on both phylloquinone (used as a model vitamin) bioaccessibility and uptake were then specifically assessed. RESULTS: The presence of pulses significantly decreased both vitamin bioaccessibility (up to -65% for ß-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, are dependent on pulse cooking method. Phylloquinone bioaccessibility is specifically impacted by saponins, tannins, and fibers while its uptake is 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.