Efficient in vitro digestion of lipids and proteins in bovine milk fat globule membrane ingredient (MFGMi) and whey-casein infant formula with added MFGMi.

The relative immaturity of the infant digestive system has the potential to affect the bioavailability of dietary lipids, proteins, and their digested products. We performed a lipidomic analysis of a commercial bovine milk fat globule membrane ingredient (MFGMi) and determined the profile of lipids and proteins in the bioaccessible fraction after in vitro digestion of both the ingredient and whey-casein-based infant formula without and with MFGMi. Test materials were digested using a static 2-phase in vitro model, with conditions simulating those in the infant gut. The extent of digestion and the bioaccessibility of various classes of neutral and polar lipids were monitored by measuring a wide targeted lipid profile using direct infusion-mass spectrometry. Digestion of abundant proteins in the ingredient and whey-casein infant formula containing the ingredient was determined by denaturing PAGE with imaging of Coomassie Brilliant Blue stained bands. Cholesterol esters, diacylglycerides, triacylglycerides, phosphatidylcholines, and phosphatidylethanolamines in MFGMi were hydrolyzed readily during in vitro digestion, which resulted in marked increases in the amounts of free fatty acids and lyso-phospholipids in the bioaccessible fraction. In contrast, sphingomyelins, ceramides, and gangliosides were largely resistant to simulated digestion. Proteins in MFGMi and the infant formulas also were hydrolyzed efficiently. The results suggest that neutral lipids, cholesterol esters, phospholipids, and proteins in MFGMi are digested efficiently during conditions that simulate the prandial lumen of the stomach and small intestine of infants. Also, supplementation of whey-casein-based infant formula with MFGMi did not appear to alter the profiles of lipids and proteins in the bioaccessible fraction after digestion.

The NCI-N87 Cell Line as a Gastric Epithelial Model to Study Cellular Uptake, Trans-Epithelial Transport, and Gastric Anti-Inflammatory Properties of Anthocyanins.

Anthocyanins are ubiquitous plant pigments with reported antioxidant, anti-inflammatory, and anti-cancer activities. To better understand these benefits, metabolism of anthocyanins requires further evaluation, especially in the stomach. Mammalian cell cultures provide useful models for investigating compound metabolism and absorption, but they are generally maintained at physiological pH. The NCI-N87 cell line is an acid-stable model of the gastric epithelium used to study gastric drug metabolism. The objective of this work was to investigate the uptake, trans-epithelial transport, and anti-inflammatory activity of anthocyanins by the NCI-N87 cell line. The cells formed a coherent monolayer, stable ≤32 days post confluency. Minimal effects on monolayer integrity were observed when the pH of the apical chamber was adjusted to pH 3.0, 5.0, or 7.4. Anthocyanins were transported across the NCI-N87 cell monolayer at 37 °C, but not at 0 °C, suggesting a facilitated process. Chokeberry anthocyanins (0-1500 µM) were not cytotoxic. At apical pH 3.0, they had anti-inflammatory properties by significantly attenuating IL-8 secretion when added to medium before, during, and after incubation with IL-1ß. These results suggest that the NCI-N87 cell line is a physiologically relevant model for in vitro studies of the transport, anti-inflammatory and potential anti-carcinogenic activities of anthocyanins in gastric tissue.

Comparison of content and in vitro bioaccessibility of provitamin A carotenoids in home cooked and commercially processed orange fleshed sweet potato (Ipomea batatas Lam).

Vitamin A deficiency (VAD) remains a public health problem in some regions of Brazil. Increased use of orange-fleshed sweet potato (OFSP) as a source of pro-vitamin A represents a potential strategy for prevention of VAD. We compared the pro-vitamin A content, vitamin A equivalency and bioaccessibility of ß-carotene (ßC) of two varieties of home cooked OFSP and two commercial sources of processed OFSP. Pro-vitamin A carotenoid content in home cooked, Beauregard variety of OFSP exceeded that in Amelia variety and commercial products for babies. All-trans-ßC was the most abundant carotenoid in raw, cooked and commercial OFSP. Boiling and frying OFSP generally decreased total ßC. A serving of 100 g FW Beauregard variety of cooked OFSP contained greater than 100% of the estimated average requirement (EAR) for children and women, and up to 92% EAR for lactating women. Although the efficiency of micellarization of all-trans-ßC during simulated digestion of OFSP was relatively low (4-8%) and significantly less than for cis-isomers, the quantities of trans-ßC incorporated into micelles from boiled Beauregard and fried Amelia varieties exceeded that in micelles generated by digesting commercial OFSP. The bioaccessibility of pro-vitamin A carotenoids in the micelle fraction of digested OFSP was confirmed with differentiated cultures of Caco-2 human intestinal cells. Continued development of OFSP such as the Amelia and Beauregard varieties that are rich in trans-ßC and dissemination of best practices for home cooking are encouraged to increase consumption of this food to decrease the risk of vitamin A deficiency in Brazil.

Zinc deficiency augments leptin production and exacerbates macrophage infiltration into adipose tissue in mice fed a high-fat diet.

Zinc (Zn) deficiency and obesity are global public health problems. Zn deficiency is associated with obesity and comorbid conditions that include insulin resistance and type 2 diabetes. However, the function of Zn in obesity remains unclear. Using a mouse model of combined high-fat and low-Zn intake (0.5-1.5 mg/kg), we investigated whether Zn deficiency exacerbates the extent of adiposity as well as perturbations in metabolic and immune function. C57BL/6 mice were randomly assigned to receive either a high-fat diet (HFD) or a control (C) diet for 6 wk, followed by further subdivision into 2 additional groups fed Zn-deficient diets (C-Zn, HFD-Zn), along with a C diet and an HFD, for 3 wk (n = 8-9 mice/group). The extent of visceral fat, insulin resistance, or systemic inflammation was unaffected by Zn deficiency. Strikingly, Zn deficiency significantly augmented circulating leptin concentrations (HFD-Zn vs. HFD: 3.15 ± 0.16 vs. 2.59 ± 0.12 µg/L, respectively) and leptin signaling in the liver of obese mice. Furthermore, gene expression of macrophage-specific markers ADAM8 (A disintegrin and metalloproteinase domain-containing protein 8) and CD68 (cluster of differentiation 68) was significantly greater in adipose tissue in the HFD-Zn group than in the HFD group, as confirmed by CD68 protein analysis, indicative of increased macrophage infiltration. Inspection of Zn content and mRNA profiles of all Zn transporters in the adipose tissue revealed alterations of Zn metabolism to obesity and Zn deficiency. Our results demonstrate that Zn deficiency increases leptin production and exacerbates macrophage infiltration into adipose tissue in obese mice, indicating the importance of Zn in metabolic and immune dysregulation in obesity.

Xanthones in mangosteen juice are absorbed and partially conjugated by healthy adults.

The proposed health-promoting effects of the pericarp from mangosteen fruit have been attributed to a family of polyphenols referred to as xanthones. The purpose of this study was to determine the bioavailability of xanthones from 100% mangosteen juice in healthy adult participants (n = 10). Pericarp particles accounted for 1% of the mass and 99% of the xanthone concentration in the juice. The juice provided 5.3 ± 0.1 mmol/L total xanthones with α-mangostin, garcinones (C, D, and E), γ-mangostin, gartanins, and other identified xanthones accounting for 58, 2, 6, 4, and 5%, respectively. Participants ingested 60 mL mangosteen juice with a high-fat breakfast. Free and conjugated (glucuronidated/sulfated) xanthones were detected in serum and urine. There was marked variation in the AUC (762-4030 nmol/L × h), maximum concentration (113 ± 107 nmol/L), and time to maximum concentration (3.7 ± 2.4 h) for α-mangostin in sera during the 24-h collection. Similarly, xanthones in 24-h urine ranged from 0.9 to 11.1 µmol and accounted for 2.0 ± 0.3% (range 0.3-3.4%) of the ingested dose. There were no significant differences between female and male participants in mean pharmacokinetic values of α-mangostin in serum and urinary xanthones. Only 15.4 ± 0.7% of total xanthones in pericarp particles in the juice partitioned into mixed micelles during in vitro digestion. These results show that xanthones in mangosteen juice are absorbed when ingested along with a high-fat meal, although release of xanthones from pericarp particles during digestion may be limited.

Gastrointestinal metabolism and bioaccessibility of selected anthocyanins isolated from commonly consumed fruits.

There is uncertainty about the identity of digestive metabolites of anthocyanins because many are naturally present in foods and/or are formed from other phenolic compounds during the digestive process. Studies using pure anthocyanins are needed to clarify this uncertainty. In this study, selected anthocyanins were purified from common fruits and individually subjected to gastric and small intestinal digestion in vitro to determine their stability, metabolites generated and bioaccessibility. Anthocyanins were highly stable during the gastric phase of simulated digestion (p > 0.05). The recovery of anthocyanins decreased during the small intestinal phase of digestion (p < 0.05). Stability was dependent on anthocyanidin structure and type of glycation (p < 0.05). Gastric and gastrointestinal phases mainly contained anthocyanins as bioaccessible flavylium cations and chalcones. Expected anthocyanin metabolites (i.e., phenolic acids and phoroglucinaldehyde) were not detected in chyme. Deglycation of anthocyanins during simulated digestion was quite limited and the bioaccessibility of intact anthocyanins was very low (0.07-2.21%).

Sweet potato beta-carotene bioefficacy is enhanced by dietary fat and not reduced by soluble fiber intake in Mongolian gerbils.

Orange-fleshed sweet potato (OFSP) is an important source of beta-carotene (betaC). Provitamin A bioefficacy from plant foods is influenced by dietary fat and fiber. We fed 3% OFSP powder diets with varying amounts of fat and soluble fiber to vitamin A (VA)-depleted Mongolian gerbils (n = 85) for 3 wk (8 groups, n = 10/group; control, n = 9) following a baseline kill (n = 6). OFSP diets differing in fat (3, 6, and 12%) contained 0.24% soluble fiber. Two additional 3% OFSP diets contained 6% fat and 3 or 9% white-fleshed sweet potato (WFSP) powder with soluble fiber contents of 0.42 and 0.80%, respectively. Control, VA-, and betaC-supplemented groups were included. Simulated digestion experiments compared the bioaccessibility of betaC from boiled vs. oil stir-fried OFSP. All OFSP diets maintained VA status and 12% fat and WFSP-added diets improved VA status above baseline (P < 0.05). Bioefficacy, as bioconversion factors, in gerbils fed 12% fat (3.5 +/- 1.4 microg betaC:1 microg VA) was improved over the 3% fat and betaC groups (6.5 +/- 3.7 and 6.7 +/- 3.7 microg betaC:1 microg VA, respectively) (P < 0.05) but did not differ from WFSP-added groups or the 6% fat group with no WFSP. Stir-frying doubled the efficiency of betaC incorporation into micelles during small intestinal digestion in support of the stimulatory effect of dietary fat on bioefficacy in vivo. Soluble fiber intake derived from WFSP did not influence bioefficacy. Replacing WFSP with OFSP will affect VA status if adopted by target groups.

Short-term aerobic exercise training in obese humans with type 2 diabetes mellitus improves whole-body insulin sensitivity through gains in peripheral, not hepatic insulin sensitivity.

CONTEXT: Short-term aerobic exercise training can improve whole-body insulin sensitivity in humans with type 2 diabetes mellitus; however, the contributions of peripheral and hepatic tissues to these improvements are not known. OBJECTIVE: Our objective was to determine the effect of 7-d aerobic exercise training on peripheral and hepatic insulin sensitivity during isoglycemic/hyperinsulinemic clamp conditions. DESIGN: Subjects were randomly assigned to one of two groups. The energy balance group consumed an isocaloric diet consisting of 50% carbohydrate, 30% fat, and 20% protein for 15 d. The energy balance plus exercise group consumed a similar diet over the 15 d and performed 50-min of treadmill walking at 70% of maximum oxygen consumption maximum during the second 7 d of the 15-d study period. Each subject underwent an initial isoglycemic/hyperinsulinemic clamp after 1-wk dietary control and a second clamp after completing the study. SETTING: The study was performed at Ohio State University's General Clinical Research Center. PARTICIPANTS: There were 18 obese, mildly diabetic humans included in the study. INTERVENTION: Aerobic exercise training was performed for 7 d. MAIN OUTCOME MEASURES: Whole-body, peripheral, and hepatic insulin sensitivity were measured. RESULTS: Exercise training did not have an impact on peripheral glucose uptake or endogenous glucose production during the basal state or low-dose insulin. Likewise, it did not alter endogenous glucose production during high-dose insulin. However, 1-wk of exercise training increased both whole-body (P<0.05) and peripheral insulin sensitivity (P<0.0001) during high-dose insulin. CONCLUSION: Improvements to whole body insulin sensitivity after short-term aerobic exercise training are due to gains in peripheral, not heptic insulin sensitivity.

In vitro micellarization and intestinal cell uptake of cis isomers of lycopene exceed those of all-trans lycopene.

The ratio of cis and all-trans lycopene (LYC) in human and animal tissues exceeds that in foods. The basis for this difference remains unknown, although differences in their stability, transport, and metabolism have been suggested. Here, we systematically compared the digestive stability, efficiency of micellarization, and uptake and intracellular stability of cis and all-trans isomers of LYC and carotenes using the coupled in vitro digestion and Caco-2 human intestinal cell model. Aril and oil from the carotenoid-rich gac fruit (Momordica cochinchinensis Spreng) were cooked with rice to provide a natural source of LYC and carotenes. The ratio of cis:trans isomers of LYC and beta-carotene was similar before and after simulated gastric and small intestinal digestion with recovery of total carotenoids in the digesta exceeding 70%. Micellarization of cis isomers of LYC during digestion of meals with both gac aril and oil was significantly greater than that of the all-trans isomer but less than for the carotenes. Uptake of cis isomers of LYC by Caco-2 cells was similar to that of carotenes and significantly greater than all-trans LYC. Micellarized carotenoids were relatively stable in micelles incubated in the cell culture environment and after accumulation in Caco-2 cells. These data suggest that the greater bioaccessibility of cis compared with all-trans isomers of LYC contributes to the enrichment of the cis isomers in tissues and that gac fruit is an excellent source of bioaccessible LYC and provitamin A carotenoids.

Impact of the stage of ripening and dietary fat on in vitro bioaccessibility of beta-carotene in 'Ataulfo' mango.

Pulp from "slightly ripe", "moderately ripe", or "fully ripe" mangoes was digested in vitro in the absence and presence of processed chicken as a source of exogenous fat and protein to examine the impact of stage of ripening of mango on micellarization during digestion and intestinal cell uptake (i.e., bioaccessibility) of beta-carotene. The quantity of beta-carotene transferred to the micelle fraction during simulated digestion significantly increased as the fruit ripened and when chicken was mixed with mango before digestion. Qualitative and quantitative changes that occur in pectin from mango pulp during the ripening process influenced the efficiency of micellarization of beta-carotene. Finally, the uptake of beta-carotene in micelles generated during simulated digestion by Caco-2 human intestinal cells confirmed the bioaccessibility of the provitamin A carotenoid in mango.

Isoflavonoid glucosides are deconjugated and absorbed in the small intestine of human subjects with ileostomies.

BACKGROUND: Although soy isoflavonoids have a number of health-promoting benefits, information concerning the sites of their absorption and metabolism in humans remains limited. Isoflavonoid absorption from the gut requires deconjugation of glucosides to aglycones. OBJECTIVE: The objective was to investigate the role of the small intestine in isoflavonoid absorption and metabolism in humans. DESIGN: Human subjects with fully functional gastrointestinal tracts (n = 6) and ileostomy subjects (n = 6) were fed a single soy meal containing 64.8 mg isoflavonoid aglycone equivalents (95% as glucosides). Metabolism of isoflavonoids in the upper gastrointestinal tract was examined by analyzing ileal effluent from ileostomy subjects, and absorption was assessed indirectly by quantifying isoflavonoids and several metabolites in 24-h urine pools. RESULTS: Chyme contained 36.7% of ingested isoflavonoid aglycone equivalents, primarily (95.8%) as aglycones. Qualitative profiles (x +/- SEM) of isoflavonoid excretion in urine (daidzein > glycitein > genistein) and the quantity of isoflavonoid equivalents were not significantly different between the control (18.4 +/- 2.2 mg) and ileostomy (13.5 +/- 3.2 mg) subjects. Dihydrodaidzein was present in the urine of all subjects, although the amount excreted by ileostomy subjects was less than that excreted by the control subjects. The percentage of producers and mean quantities of dihydrogenistein, equol, and O-desmethylangolensin in the urine of ileostomy subjects also were lower than those of control subjects. CONCLUSIONS: Ileostomy subjects efficiently deglycosylate isoflavonoid glucosides in the small intestine and appear to absorb aglycones with an efficiency comparable with that of control subjects. However, the production of microbial metabolites of isoflavonoids is limited in ileostomy subjects.

Impact of fatty acyl composition and quantity of triglycerides on bioaccessibility of dietary carotenoids.

A carotenoid-rich salad meal with varying amounts and types of triglycerides (TG) was digested using simulated gastric and small intestinal conditions. Xanthophylls (lutein and zeaxanthin) and carotenes (alpha-carotene, beta-carotene, and lycopene) in chyme and micelle fraction were quantified to determine digestive stability and efficiency of micellarization (bioaccessibility). Micellarization of lutein (+zeaxanthin) exceeded that of alpha- and beta-carotenes, which was greater than that of lycopene for all test conditions. Micellarization of carotenes, but not lutein (+zeaxanthin), was enhanced (P < 0.05) by addition of TG (2.5% v/w) to the meal and was dependent on fatty acyl chain length in structured TG (c18:1 > c8:0 > c4:0). The degree of unsaturation of c18 fatty acyl chains in TG added to the salad purée did not significantly alter the efficiency of micellarization of carotenoids. Relatively low amounts of triolein and canola oil (0.5-1%) were required for maximum micellarization of carotenes, but more oil (approximately 2.5%) was required when TG with medium chain saturated fatty acyl groups (e.g., trioctanoin and coconut oil) was added to the salad. Uptake of lutein and beta-carotene by Caco-2 cells also was examined by exposing cells to micelles generated during the simulated digestion of salad purée with either triolein or trioctanoin. Cell accumulation of beta-carotene was independent of fatty acyl composition of micelles, whereas lutein uptake was slightly, but significantly, increased from samples with digested triolein compared to trioctanoin. The results show that the in vitro transfer of alpha-carotene, beta-carotene, and lycopene from chyme to mixed micelles during digestion requires minimal (0.5-1%) lipid content in the meal and is affected by the length of fatty acyl chains but not the degree of unsaturation in TG. In contrast, fatty acyl chain length has limited if any impact on carotenoid uptake by small intestinal epithelial cells. These data suggest that the amount of TG in a typical meal does not limit the bioaccessibility of carotenoids.

Supplementation of test meals with fat-free phytosterol products can reduce cholesterol micellarization during simulated digestion and cholesterol accumulation by Caco-2 cells.

Phytosterols have been shown to reduce cholesterol absorption in humans. Supplementing phytosterols in fat-free formulations, however, has yielded controversial results. In the present study, we investigated the effect of supplementing test meals with different fat-free phytosterol products on cholesterol incorporation into mixed micelles during simulated digestion and accumulation of micellar cholesterol by Caco-2 cells: control orange juice (OJ), orange juice supplemented with either multivitamin/multimineral tablets (MVT), multivitamin/multimineral tablets containing phytosterols (MVT+P), and phytosterol powder (PP). These combinations were added to Ensure-based test meals and spiked with cholesterol of natural isotopic composition or 13C2-cholesterol to differentiate external from endogenous cholesterol. After simulated gastric/small intestinal digestion, micelle fractions were analyzed for cholesterol enzymatically (n = 6-20/product) and by high-performance liquid chromatography-tandem mass spectrometry (n = 12/product) and added to Caco-2 cells to determine the accumulation of 13C2-cholesterol (n = 10-24/product). As compared to OJ, PP and MVT+P significantly decreased cholesterol micellarization (determined enzymatically) by 70 +/- 39 (mean +/- SD) and 70 +/- 39%, respectively (P < 0.001, Bonferroni). The stable isotope experiments revealed that both PP and MVT+P reduced cholesterol micellarization [by 25 +/- 12 (P = 0.055) and 21 +/- 8% (P = 0.020), respectively, Fisher's protected LSD test] and Caco-2 cell accumulation (by 28 +/- 8 and 10 +/- 8%, respectively; P < 0.010, Bonferroni). OJ+P did not inhibit micellarization or accumulation of cholesterol by Caco-2 cells. This study shows that fat-free phytosterol-containing products can significantly inhibit cholesterol micellarization and Caco-2 cell bioaccessibility, albeit to different extents depending on individual formulations. This is most likely explained by inhibition of cholesterol micellarization.

Assessment of coenzyme Q10 absorption using an in vitro digestion-Caco-2 cell model.

The feasibility of using a coupled in vitro digestion-Caco-2 cell uptake as a model for examining the digestive stability and absorption of coenzyme Q10 (CoQ10) from a variety of commercially available CoQ10 products was examined. The products were first subjected to simulated digestion to mimic their passage through the GI tract to generate micelles containing CoQ10, and the micelle fractions added to monolayers of Caco-2 cells to determine CoQ10 uptake. The data demonstrate enhanced uptake of CoQ10 from formulations containing solubilized forms of CoQ10 and also from a CoQ10-gamma-cyclodextrin complex as compared with pure CoQ10 powder or tablets based on CoQ10 powder. The CoQ10 uptake by the cells was correlated with the extent of micellarization of CoQ10 during simulated digestion. Most of CoQ10 taken up by the cells was converted to ubiquinol either during or following uptake. The data also indicate a correlation between in vitro dissolution of CoQ10 products and uptake of CoQ10 by Caco-2 cells. Thus, this study demonstrates the utility of coupled in vitro digestion-Caco-2 cell model as a cost-effective screening tool that will provide useful information for the optimal design of human trials to assess the bioavailability of CoQ10 and also other bioactive compounds.

Micellarization and intestinal cell uptake of beta-carotene and lutein from drumstick (Moringa oleifera) leaves.

The leaves and pods of the drumstick tree are used as food and medicine in some Asian and African countries. Although relatively high concentrations of beta-carotene and lutein have been reported in the leaves, the bioavailability of these carotenoids from this source is unknown. We have analyzed the digestive stability and bioaccessibility of carotenoids in fresh and lyophilized drumstick leaves using the coupled in vitro digestion/Caco-2 cell model. Beta-carotene and lutein were stable during simulated gastric and small intestinal digestion. The efficiency of micellarization of lutein during the small intestinal phase of digestion exceeded that of beta-carotene. Addition of peanut oil (5% vol/wt) to the test food increased micellarization of both carotenoids, and particularly beta-carotene. Caco-2 cells accumulated beta-carotene and lutein from micelles generated during digestion of drumstick leaves in a time- and concentration-dependent manner. The relatively high bioaccessibility of beta-carotene and lutein from drumstick leaves ingested with oil supports the potential use of this plant food for improving vitamin A nutrition and perhaps delaying the onset of some degenerative diseases such as cataracts.

Bioaccessibility and intestinal cell uptake of astaxanthin from salmon and commercial supplements.

Although the keto-carotenoid astaxanthin (Ast) is not typically present in human plasma due to its relative scarcity in the typical diet, global consumption of salmon, the primary source of Ast in food, and Ast supplements continues to increase. The first objective of the present study was to investigate the bioaccessibility of Ast from uncooked and cooked fillets of wild and aquacultured salmon, Ast-supplements and krill oil, during simulated gastric and small intestinal digestion. Uptake of E-Ast from micelles generated during digestion of wild salmon by monolayers of Caco-2 was also monitored. Both wild and aquacultured salmon flesh contained E-Ast and Z-isomers of unesterified Ast, whereas Ast esters were the predominant form of the carotenoid in commercial supplements and krill oil. Flesh from wild salmon contained approximately 10 times more Ast than aquacultured salmon. Common styles of cooking flesh from wild and aquacultured salmon decreased Ast content by 48-57% and 35-47%, respectively. Ast in salmon flesh, supplements and krill oil was relatively stable (>80% recovery) during in vitro digestion. The efficiency of transfer of Ast into mixed micelles during digestion of uncooked wild salmon was 43%, but only 12% for uncooked acquacultured salmon. Cooking wild salmon significantly decreased Ast bioaccessibility. The relative bioaccessibility of Ast (41-67%) after digestion of oil vehicle in commercial supplements was inversely proportional to carotenoid content (3-10mg/capsule), whereas bioaccessibility of endogenous Ast in phospholipid-rich krill oil supplement was 68%. >95% of Ast in mixed micelles generated during digestion of supplements and krill oil was unesterified. Caco-2 intestinal cells accumulated 11-14% of E-Ast delivered in mixed micelles generated from digested wild salmon. Apical uptake and basolateral secretion of E-Ast by Caco-2 cells grown on inserts were greater after digestion of Ast-enriched krill oil compared to uncooked wild salmon. These data suggest that the bioacessibility of Ast in wild salmon and soft-gel capsules is greater than that in aquacultured salmon, and that uptake and basolateral secretion of the carotenoid by enterocyte-like cells is enhanced by the digestion products of phospholipid-rich krill oil.

Potential of golden potatoes to improve vitamin A and vitamin E status in developing countries.

Potato (Solanum tuberosum L.) is the third most widely consumed plant food by humans. Its tubers are rich in starch and vitamin C, but have low or null levels of essential nutrients such as provitamin A and vitamin E. Transformation of potato with a bacterial mini-pathway for ß-carotene in a tuber-specific manner results in a "golden" potato (GP) tuber phenotype resulting from accumulation of provitamin A carotenoids (α- and ß-carotene) and xanthophylls. Here, we investigated the bioaccessibility of carotenoids and vitamin E as α-tocopherol (αTC) in boiled wild type and golden tubers using in vitro digestion. Golden tubers contained up to 91 µg provitamin A carotenes (PAC)/g D, increased levels of xanthophylls, phytoene and phytofluene, as well as up to 78 µg vitamin E/g DW. Cubes from wild type and GP tubers were boiled and subjected to simulated digestion to estimate bioaccessibility of carotenoids and αTC. Retention in boiled GPs exceeded 80% for ß-carotene (ßC), α-carotene (αC), lutein, phytoene ± and αTC, but less than 50% for phytofluene. The efficiency of partitioning of total ßC, αC, E-lutein, phytoene, phytofluene and αTC in the mixed micelle fraction during small intestinal digestion was influenced by genotype, tuber content and hydrophobicity. Apical uptake of the compounds that partitioned in mixed micelles by monolayers of human intestinal Caco-2 cells during incubation for 4h was 14-20% for provitamin A and xanthophylls, 43-45% for phytoene, 23-27% for phytofluene, and 53% for αTC. These results suggest that a 150 g serving of boiled golden potatoes has the potential to contribute 42% and 23% of the daily requirement of retinol activity equivalents (RAE), as well as 34 and 17% of the daily vitamin E requirement for children and women of reproductive age, respectively.

Comparison of Two Static in Vitro Digestion Methods for Screening the Bioaccessibility of Carotenoids in Fruits, Vegetables, and Animal Products.

In vitro digestion methods are routinely used to assess the bioaccessibility of carotenoids and other dietary lipophilic compounds. Here, we compared the recovery of carotenoids and their efficiency of micellarization in digested fruits, vegetables, egg yolk, and salmon and also in mixed-vegetable salads with and without either egg yolk or salmon using the static INFOGEST method22 and the procedure of Failla et al.16 Carotenoid stability during the simulated digestion was ≥70%. The efficiencies of the partitioning of carotenoids into mixed micelles were similar when individual plant foods and salad meals were digested using the two static methods. Furthermore, the addition of cooked egg or salmon to vegetable salads increased the bioaccessibility of some carotenoids. Our findings showed that the two methods of in vitro digestion generated similar estimates of carotenoid retention and bioaccessibility for diverse foods.

Intestinal microbial dysbiosis and colonic epithelial cell hyperproliferation by dietary α-mangostin is independent of mouse strain.

Beverages and supplements prepared from mangosteen fruit are claimed to support gut health and immunity, despite the absence of supporting evidence from clinical trials. We recently reported that α-mangostin (α-MG), the most abundant xanthone in mangosteen fruit, altered the intestinal microbiome, promoted dysbiosis, and exacerbated colitis in C57BL/6J mice. The objective of this study was to determine whether induction of dysbiosis by dietary α-MG is limited to the C57BL/6J strain or represents a more generic response to chronic intake of the xanthone on the gut microbiota of mice. C3H, Balb/c, Nude FoxN1nu, and C57BL/6J mice, each demonstrating unique microbiomes, were fed standard diet or diet containing 0.1% α-MG for four weeks. Dietary α-MG significantly altered the cecal and colonic microbiota in all four strains of mice, promoting a reduction in generally assumed beneficial bacterial groups while increasing the abundance of pathogenic bacteria. Consumption of α-MG was associated with reduced abundance of Firmicutes and increased abundance of Proteobacteria. The abundance of Lachnospiraceae, Ruminococcaceae, and Lactobacillaceae was reduced in α-MG-fed mice, while that of Enterobacteriaceae and Enterococcaceae was increased. Dietary α-MG also was associated with increased proliferation of colonic epithelial cells, infiltration of immune cells, infiltration of immune cells and increased fluid content in stool. These results suggest that ingestion of pharmacologic doses of xanthones in mangosteen-containing supplements may adversely alter the gut microbiota and should be used with caution.

α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial.

BACKGROUND: Increasing dietary fat intake is expected to improve α-tocopherol bioavailability, which could be beneficial for improving α-tocopherol status, especially in cohorts at high cardiometabolic risk who fail to meet dietary α-tocopherol requirements. OBJECTIVE: Our objective was to assess dose-dependent effects of dairy fat and metabolic syndrome (MetS) health status on α-tocopherol pharmacokinetics in plasma and lipoproteins. DESIGN: A randomized, crossover, double-blind study was conducted in healthy and MetS adults (n = 10/group) who ingested encapsulated hexadeuterium-labeled (d6)-RRR-α-tocopherol (15 mg) with 240 mL nonfat (0.2 g fat), reduced-fat (4.8 g fat), or whole (7.9 g fat) milk before blood collection at regular intervals for 72 h. RESULTS: Compared with healthy participants, those with MetS had lower (P < 0.05) baseline plasma α-tocopherol (µmol/mmol lipid) and greater oxidized low-density lipoprotein (LDL), interleukin (IL)-6, IL-10, and C-reactive protein. Regardless of health status, d6-α-tocopherol bioavailability was unaffected by increasing amounts of dairy fat provided by milk beverages, but MetS participants had lower estimated d6-α-tocopherol absorption (±SEM) than did healthy participants (26.1% ± 1.0% compared with 29.5% ± 1.1%). They also had lower plasma d6-α-tocopherol AUC from 0 to 72 h, as well as maximal concentrations (Cmax: 2.04 ± 0.14 compared with 2.73 ± 0.18 µmol/L) and slower rates of plasma disappearance but similar times to Cmax. MetS participants had lower d6-α-tocopherol AUC from t = 0-12 h (AUC0- t final) in lipoprotein fractions [chylomicron, very-low-density lipoprotein (VLDL), LDL, high-density lipoprotein]. Percentages of d6-α-tocopherol AUC0- t final in both the chylomicron (r = -0.46 to -0.52) and VLDL (r = -0.49 to -0.68) fractions were inversely correlated with oxidized LDL, IL-10, IL-6, and C-reactive protein. CONCLUSIONS: At dietary intakes equivalent to the Recommended Dietary Allowance, α-tocopherol bioavailability is unaffected by dairy fat quantity but is lower in MetS adults, potentially because of greater inflammation and oxidative stress that limits small intestinal α-tocopherol absorption and/or impairs hepatic α-tocopherol trafficking. These findings support higher dietary α-tocopherol requirements for MetS adults. This trial was registered at www.clinicaltrials.gov as NCT01787591.