Effect of a carotenoid-producing Bacillus strain on intestinal barrier integrity and systemic delivery of carotenoids : a randomised trial in animals and humans

The aim of the present study was to investigate effects of the carotenoid-producing Bacillus indicus strain PD01 on intestinal barrier function and its ability to survive passage through the gastrointestinal tract and to assess systemic bioavailability of these carotenoids in vivo. As model for impaired barrier function, 16 early weaned piglets were randomly assigned to a control diet or control diet with PD01 for 23 days. In addition, 67 overweight/obese, otherwise healthy individuals were randomly assigned to groups receiving PD01 or placebo for 6 weeks. PD01 survived passage through the gastrointestinal tract in piglets and human subjects and resulted in significant accumulation of PD01 derived carotenoids (methyl-glycosyl-apo-8'-lycopenoate and glycosyl-apo-8'- lycopene) in human plasma after 3- and 6-weeks supplementation versus baseline (0.044 and 0.076 vs 0 mu M, respectively; p = 0.104). In summary, PD01 survived transit through the gastrointestinal tract, resulted in systemic carotenoid accumulation and improved compromised barrier function outcomes

Effets de l'apport en acides gras polyinsaturés Oméga 3 sous forme de phospholipides (étude chez le rat et sur modèle cellulaire)

De nombreuses études ont montré que l'augmentation de l'apport en acides gras polyinsaturés oméga 3 induit des effets bénéfiques sur de nombreuses pathologies cardiaques, neurologiques et inflammatoires. Nos travaux ont donc tenté de mieux appréhender les effets de la supplémentation en acides gras polyinsaturés oméga 3 et plus particulièrement en phospholipides riches en acide docosahexaénoïque (DHA, C22:6 3) sur le métabolisme des acides gras lors d'une étude in vivo chez le rat et sur la fonctionnalité cellulaire lors d'une étude in vitro sur un modèle cellulaire. L'apport de phospholipides riches en DHA à différentes doses à des rats induit une modification de la composition en acides gras des lipides sanguins et notamment une accrétion de la teneur en acide arachidonique (C20:4 6). Cette accrétion est corrélée négativement avec l'apport en acides gras polyinsaturés oméga 6 et positivement avec l'apport spécifique en DHA. L'effet de la supplémentation en DHA au niveau du métabolisme des acides gras semble être dose-dépendant avec une allure de courbe en cloche et peut être attribuable à la forme de vectorisation phospholipide. L'étude cellulaire montre que la variation de l'apport en acides gras polyinsaturés sous forme de phospholipides modifie les propriétés biophysiques des membranes en modulant la composition en acides gras des phospholipides et influe sur l'efficacité de certaines protéines membranaires. Cette étude montre également l'importance du rapport des acides gras 6/ 3 présents dans les phospholipides car ceux-ci peuvent devenir létaux quand l'apport en acides gras polyinsaturés oméga 3 est trop important. Ces études ont permis de montrer que l'effet observé lors d'une supplémentation en acides gras polyinsaturés oméga 3 peut être soit bénéfique soit néfaste en fonction de la dose d'acides gras polyinsaturés administrée, du vecteur utilisé et du rapport 6/ 3 présent dans les suppléments.Many studies have shown that the increase of omega 3 polyunsaturated fatty acids intake induces beneficial effects on various diseases such as cardiac, neurological and inflammatory diseases. Our work aims to better understand the effects of omega 3 polyunsaturated fatty acids (PUFA) supplementation and in particular docosahexaenoic acid (C22:6 3) rich phospholipids supplementation on both fatty acid metabolism and cellular functionality. We showed by an in vivo study in rats that diet supplementation with DHA enriched phospholipids at various amounts results in a modification of the fatty acid composition of blood lipids with, in particular, an accretion of the arachidonic acid level (C20:4 6). This increase is correlated negatively with the omega 6 PUFA intake but positively with the DHA intake. The effect of the DHA supplementation on fatty acid metabolism seems to be dose dependent with a bell-shaped curve and probably liked to the PUFA vectorization form. The in vitro study on a cellular model showed that the addition of various amount of PUFA under the form of phospholipids modifies the biophysical properties of the membranes by modulating the fatty acid composition of the phospholipid and thereby influenced the efficiency of membrane proteins. In this study, we also showed that addition of a too high amount of omega 3 PUFA under the form of phospholipid become letal for the cells thus highlighting the critical importance of the 6/ 3 fatty acids ratio in phospholipids. In conclusion, these two studies allowed us to show that omega 3 PUFA supplementation has an effect which can be either beneficial or detrimental depending on the dose of omega 3 PUFA supplied, the vectorization form and the 6/ 3 ratio of the supplement.AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Simple and fast HPLC method for simultaneous determination of retinol, tocopherols, coenzyme Q10 and carotenoids in complex samples

International audienceThe effects of fat-soluble vitamins (such as vitamins A and E) and lipid microconstituents (such as carotenoids) on human health are now well established. However, high-performance liquid chromatography (HPLC) methods able to detect these molecules in simultaneous runs are often difficult to set up. We report here a 35-min reversed-phase HPLC method using a single C30 column kept at 35 degrees C with a gradient system of methanol, methyl-tert-butyl ether and water at a flow-rate of 1 mL/min. This method resolves 11 carotenoids, retinol, alpha- and gamma-tocopherol from complex matrixes such as food samples, human plasma and human adipose tissue within 35 min. The method is also able to separate coenzyme Q(10). The intra-day and inter-day coefficients of variation are suitable for routine clinical and scientific applications for the determination of lipid micronutrients from various sample types

Are lutein, lycopene, and β-carotene lost through the digestive process?

International audienceThe bioavailability of many carotenoids has been assessed, but little attention has been given to the metabolism of these antioxidant compounds during digestion. The isomerization and loss of lutein, lycopene, and β-carotene incorporated into a lipid-rich liquid meal was determined in vitro through the gastric, duodenal, and jejunal phases in the presence and absence of digestive enzymes, and in the presence and absence of known oxidizing agents often found in mixed meals (metmyoglobin in red meat and ferrous sulfate in supplemental iron). Carotenoids were quantitated using HPLC-PDA. In the absence of enzymes, lutein and lycopene were lost during earlier phases of the digestive process. In the presence of enzymes, lutein and lycopene were robust through the gastric and duodenal phases, with statistically significant losses of 40% and 20%, respectively, observed only during the jejunal phase. Regardless of the presence or absence of enzymes, an initial 25% of β-carotene was lost during the gastric phase, but no further loss was observed. Ferrous sulfate had no significant impact on any carotenoid level. Metmyoglobin had no impact on lutein, but significantly reduced lycopene and β-carotene levels by 30% and 80%, respectively, by the end of the jejunal phase. No significant isomerization was observed between the initial and jejunal phases for any of the carotenoids

Lycopene attenuates LPS-induced TNF-alpha secretion in macrophages and inflammatory markers in adipocytes exposed to macrophage-conditioned media

International audienceScope Adipose tissue is infiltrated by an increasing number of macrophages during the development of obesity. These immune cells are suspected to be a major source of TNF-a that interferes with adipocyte function. Because lycopene possesses anti-inflammatory properties, we hypothesize that lycopene could reduce the production of TNF-a by macrophages and thus interfere in the cross-talk between macrophages and adipocytes. Methods and results We demonstrated that physiological concentrations of lycopene were able to attenuate the lipopolysaccharide (LPS)-mediated induction of TNF-a in RAW 264.7 macrophages, at both the mRNA and protein levels. The molecular mechanism was studied. It appeared that the LPS-activation of both JNK and NF-?B signaling pathways was modulated by lycopene. The anti-inflammatory effects of lycopene on macrophages were accompanied by a decrease in LPS-stimulated macrophage migration in the presence of lycopene. Furthermore, lycopene decreased macrophage conditioned medium-induced proinflammatory cytokine, acute phase protein, and chemokine mRNA expression in 3T3-L1 adipocytes. Conclusion These data indicate that lycopene displayed an anti-inflammatory effect on macrophages that beneficially impacted adipocyte function. Thus, these results suggest that lycopene could block the vicious cycle that occurs between adipocytes and macrophages in adipose tissue during obesity

Phytosterols can impair vitamin D intestinal absorption in vitro and in mice

International audienceScope: Adequate vitamin D status is necessary and beneficial for health, although deficiency and insufficiency are very common. As cholecalciferol (vitamin D3) structure is close to cholesterol structure, we hypothesized that phytosterols, frequently used to decrease cholesterol, intestinal absorption and consequently to reduce hypercholesterolemia, may also interact with cholecalciferol absorption. Methods and results: β-Sitosterol effect on cholecalciferol postprandial response was first assessed in mice. We then evaluated the effect of different sterols on (i) cholecalciferol micellar incorporation, (ii) cholecalciferol apical uptake and (iii) basolateral efflux in vitro or ex vivo. In mice, cholecalciferol bioavailability was 15-fold lower in the presence of β-sitosterol (p<0.05). This can partly be explained by the fact that phytosterols significantly impaired cholecalciferol incorporation into mixed micelles (from −16 to −36% depending on sterol micellar composition). This can also be due to the fact that in Caco-2 cells and mouse intestinal explants, phytosterols significantly lowered cholecalciferol apical uptake (from −13 to −39%). Conversely, phytosterols had no effect on cholecalciferol secretion at the basolateral side of Caco-2 cells. Conclusion: The present data suggest for the first time that phytosterols can interact with vitamin D3 intestinal absorption. This interaction can be explained by a competition for micellar incorporation and for apical uptak

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

International audienceScope: 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 (-FeSO4) and with ferrous sulfate (160 mg, +FeSO4). Subjects were intubated with a naso-gastric/naso-duodenal tube. Digesta, blood plasma, and the triglyceride-rich lipoprotein (TRL) fractions of plasma were analyzed using LC–MS/MS, to measure LYC and apo-lycopenoids. Results: Digesta LYC concentrations increased with time (p = 1.2 × 10−7), decrease with time × iron (p = 1.1 × 10−5), and remain ≈200× higher than apo-lycopenals/lycopenone. Digesta apo-8′-, -10′-, -12′-, -14′-, -15-lycopenal, and apo-13-lycopenone concentrations increased with time (p Conclusions: FeSO4 reduces LYC absorption. Apo-lycopenals appear to be absorbed from foods, and not made in significant quantities during digestion

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

International audienceScope: 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 (-FeSO4) and with ferrous sulfate (160 mg, +FeSO4). Subjects were intubated with a naso-gastric/naso-duodenal tube. Digesta, blood plasma, and the triglyceride-rich lipoprotein (TRL) fractions of plasma were analyzed using LC–MS/MS, to measure LYC and apo-lycopenoids. Results: Digesta LYC concentrations increased with time (p = 1.2 × 10−7), decrease with time × iron (p = 1.1 × 10−5), and remain ≈200× higher than apo-lycopenals/lycopenone. Digesta apo-8′-, -10′-, -12′-, -14′-, -15-lycopenal, and apo-13-lycopenone concentrations increased with time (p Conclusions: FeSO4 reduces LYC absorption. Apo-lycopenals appear to be absorbed from foods, and not made in significant quantities during digestion

Fatty acids affect micellar properties and modulate vitamin D uptake and basolateral efflux in Caco-2 cells

International audienceWe have recently shown that vitamin D-3 (cholecalciferol) absorption is not a simple passive diffusion but involves cholesterol transporters. As free fatty acids (FAs) modulate cholesterol intestinal absorption and metabolism, we hypothesized that FAs may also interact with vitamin D absorption. Effects of FAs were evaluated at different levels of cholecalciferol intestinal absorption. First, the physicochemical properties of micelles formed with different FAs were analyzed. The micelles were then administered to human Caco-2 cells in culture to evaluate FA effects on (i) cholecalciferol uptake and basolateral efflux and (ii) the regulation of genes coding proteins involved in lipid absorption process. Micellar electric charge was correlated with both FA chain length and degree of unsaturation. Long-chain FAs at 500 mu M in mixed micelles decreased cholecalciferol uptake in Caco-2 cells. This decrease was annihilated as soon as the long-chain FAs were mixed with other FAs. Oleic acid significantly improved cholecalciferol basolateral efflux compared to other FAs. These results were partly explained by a modulation of genes coding for lipid transport proteins such as Niemann-pick C1-like 1 and scavenger receptor class B type I. The data reported here show for the first time that FAs can interact with cholecalciferol intestinal absorption at different key steps of the absorption process. Cholecalciferol intestinal absorption may thus be optimized according to oil FA composition. (c) 2013 Elsevier Inc. All rights reserved