Exopolysaccharides from milk fermented by lactic acid bacteria enhance dietary carotenoid bioavailability in humans in a randomized crossover trial and in rats.

BACKGROUND: Dietary supplementation with carotenoids can have beneficial health effects, but carotenoids are poorly absorbed. OBJECTIVES: We aimed to evaluate how milk fermented by lactic acid bacteria affects dietary carotenoid bioavailability in humans and rats and to investigate mechanisms by which active components in milk fermented by Lactobacilli enhance dietary carotenoid absorption. METHODS: Male rats (n = 8/group) were administered ß-carotene or ß-carotene + fermented milk. Rats (n = 6/group) were also pretreated with ezetimibe, a cholesterol absorption inhibitor, to investigate ß-carotene transport mechanisms. In humans, 3 studies were conducted using a randomized crossover method. Subjects (n = 16/study) consumed a vegetable (carrot, tomato, or spinach) drink alone or with a fermented milk drink. Blood samples were collected at various time points after consumption. RESULTS: In rats, the serum ß-carotene area under the concentration-time curve (AUC) was significantly higher for the ß-carotene + fermented milk than for ß-carotene only. A significant correlation (r = 0.83, P < 0.001) between the exopolysaccharide (EPS) content of fermented milk and serum ß-carotene AUC was observed. Ezetimibe treatment did not suppress elevations in serum ß-carotene concentrations induced by fermented milk ingestion. In humans, the incremental area under the concentration-time curve (iAUC) for ß-carotene in the plasma triacylglycerol-rich lipoprotein (TRL) fraction was significantly (1.8-fold, range: 0.6-3.9) higher when carrot + fermented milk was consumed compared with carrot drink alone. A significantly (6.5-fold, range: 0.04-7.7) higher iAUC for lycopene in the plasma TRL fraction was observed for subjects who consumed tomato + fermented milk compared with tomato drink alone. A significant increase in plasma lutein in all fractions was observed after consumption of spinach + fermented milk, but not with spinach drink alone. CONCLUSIONS: Co-ingestion of ß-carotene and fermented milk significantly increased dietary ß-carotene bioavailability in humans and rats. EPSs could affect the physical properties of fermented milk to enhance dietary ß-carotene absorption mediated by simple diffusion mechanisms. These findings may be relevant for methods to increase dietary carotenoid bioavailability.This trial was registered at umin.ac.jp/ctr as UMIN000034838, UMIN000034839, and UMIN000034840.

The beneficial role of functional food components in mitigating ultraviolet-induced skin damage.

Excessive exposure to ultraviolet (UV) radiation can chemically alter biological molecules and is one of the major environmental health risks with potential to damage the structure and function of the skin. Numerous dietary supplements are known to optimize the skin's defenses against radiation exposure. Several studies in which the beneficial roles of functional food components, that can protect against UV-induced skin damage, have been demonstrated. Supplemental dietary sphingomyelin maintains covalently bound ω-hydroxy ceramides to avert skin barrier defects after UVB irradiation. The oral administration of collagen hydrolysates has been shown to limit decreases in skin elasticity via increases in the dermal hyaluronic acid content. Milk fermented with lactic acid bacteria has been shown to augment DNA repair mechanisms and improve skin immunity in the aftermath of UVB damage. Furthermore, long-term ingestion of fermented milk containing lactic acid bacteria, collagen hydrolysates and sphingomyelin increases the minimal erythema dose (MED) in human subjects with moderate sunburn or redness and tanned skin after exposure to UV solar radiation. Thus, products containing these functional food components are one means by which the adverse effects of UV radiation on the skin can be mitigated.

Milk Fermented by Lactic Acid Bacteria Enhances the Absorption of Dietary Sphingomyelin in Rats.

Supplementation with sphingomyelin has been reported to prevent disease and maintain good health. However, intact sphingomyelin and ceramides are poorly absorbed compared with glycerolipids. Therefore, if the bioavailability of dietary sphingomyelin can be increased, supplementation would be more effective at lower doses. The aim of this study in rats was to evaluate the effect of fermented milk on the bioavailability of dietary sphingomyelin in rats. After the rats had fasted for 15 h, test solutions were administrated orally. Blood samples were collected from the tail vein before and 90, 180, 270, and 360 min after administration. Compared with sphingomyelin/milk phospholipids concentrate (MPL) alone, co-ingestion of sphingomyelin/MPL with fermented milk caused an approximate twofold significant increase in serum ceramides containing d16:1 sphingosine with 16:0, 22:0, 23:0 and 24:0 fatty acids, which was derived from the ingested sphingomyelin. While nonfat milk also increased the serum levels of these ceramides, fermented milk was more effective. Co-ingestion of the upper layer of fermented milk or exopolysaccharide concentrate prepared from fermented milk significantly increased serum ceramide levels. X-ray diffraction analysis also showed addition of fermented milk or EPS concentrate to sphingomyelin eliminated the characteristic peak of sphingomyelin. This study demonstrated for the first time that co-ingestion of dietary sphingomyelin and fermented milk, compared with ingestion of dietary sphingomyelin alone, caused a significant increase in the absorption of sphingomyelin. Our results indicate exopolysaccharides in fermented milk may contribute to inhibition of sphingomyelin crystallization, resulting in enhanced absorption of dietary sphingomyelin in rats.

A novel mechanism for improvement of dry skin by dietary milk phospholipids: Effect on epidermal covalently bound ceramides and skin inflammation in hairless mice.

BACKGROUND: Dietary milk phospholipids (MPLs) increase hydration of the stratum corneum and reduced transepidermal water loss (TEWL) in hairless mice fed a standard diet. However, the mechanism by which MPLs improve skin barrier functions has yet to be established. OBJECTIVE: This study was designed to examine the mechanism by which MPLs may affect covalently bound ceramides and markers of skin inflammation and improve the skin barrier defect in hairless mice fed a magnesium-deficient (HR-AD) diet. METHODS: Four-week-old female hairless mice were randomized into four groups (n=10/group), and fed a standard (control) diet, the HR-AD diet, the HR-AD diet supplemented with either 7.0 g/kg MPLs (low [L]-MPL) or 41.0 g/kg MPLs (high [H]-MPL). RESULTS: Dietary MPLs improved the dry skin condition of hairless mice fed the HR-AD diet. MPLs significantly increased the percentage of covalently bound ω-hydroxy ceramides in the epidermis, and significantly decreased both thymus and activation-regulated chemokine (TARC) mRNA and thymic stromal lymphopoietin (TSLP) mRNA levels in skin, compared with the HR-AD diet. Furthermore, the MPL diets significantly decreased serum concentrations of immunoglobulin-E, TARC, TSLP, and soluble P-selectin versus the HR-AD diet. CONCLUSION: Our study showed for the first time that dietary MPLs may modulate epidermal covalently bound ceramides associated with formation of lamellar structures and suppress skin inflammation, resulting in improved skin barrier function.

Dietary whey hydrolysate with exercise alters the plasma protein profile: a comprehensive protein analysis.

OBJECTIVE: It has been shown that dietary whey protein accelerates glucose uptake by altering glycoregulatory enzyme activity in skeletal muscle. In the present study, we investigated the effect of dietary whey protein on endurance and glycogen resynthesis and attempted to identify plasma proteins that reflected the physical condition by a comprehensive proteomics approach. METHODS: Male c57BL/6 mice were divided into four groups: sedentary, sedentary with whey protein hydrolysate, exercise, and exercise with whey protein hydrolysate. The mice in the exercise groups performed treadmill running exercise five times per week for 4 wk. Protein profiling of plasma sample obtained from individuals was performed, as were measurements of endurance performance and the glycogen content of gastrocnemius muscle. RESULTS: After the training period, the endurance of mice fed the whey diet was improved compared with that of mice fed the control diet. Muscle glycogen content was significantly increased after 4 wk of exercise, and intake of whey protein led to a further increase in glycogen. Apolipoproteins A-II and C-I and ß(2)-glycoprotein-1 were found to be altered by training combined with the intake of whey protein, without significant changes induced by exercise or whey protein alone. CONCLUSION: Results of the present study suggest that these three proteins may be potential biomarkers of improved endurance and glycogen resynthesis and part of the mechanism that mediates the benefits of whey protein.

Preexercise ingestion of carbohydrate plus whey protein hydrolysates attenuates skeletal muscle glycogen depletion during exercise in rats.

OBJECTIVE: Depletion of glycogen stores is associated with fatigue during both sprint and endurance exercises and therefore it is considered important to maintain adequate tissue stores of glycogen during exercise. The aims of the present study in rats were therefore to investigate the effects of preexercise supplementation with carbohydrate and whey protein hydrolysates (WPH) on glycogen content, and phosphorylated signaling molecules of key enzymes that regulate glucose uptake and glycogen synthesis during exercise. METHODS: Male SD rats were used in the study (n=7/group). Prior to exercise, one group of rats was sacrificed, whereas the other groups were given either water, glucose, or glucose plus WPH solutions. After ingestion of the test solutions, glycogen-depleting exercise was carried out for 60 min. The rats were then sacrificed and the triceps muscles excised quickly. RESULTS: Compared to water or glucose only, preexercise ingestion of glucose plus WPH caused a significant attenuation of muscle glycogen depletion during the postexercise period. Coingestion of glucose and WPH also significantly lowered phosphorylated glycogen synthase levels compared to ingestion of water only. In the glucose plus WPH group, the levels of phosphorylated Akt were increased significantly compared to the group ingesting water only, while the levels of phosphorylated PKC were significantly higher than in the groups ingesting only water or glucose. CONCLUSION: Taken together, these results indicate that, compared to ingestion of glucose or water only, preexercise ingestion of carbohydrate plus WPH activates skeletal muscle proteins of key enzymes that regulate glucose uptake and glycogen synthesis during exercise, thereby attenuating exercise-induced glycogen depletion.

Post-exercise carbohydrate plus whey protein hydrolysates supplementation increases skeletal muscle glycogen level in rats.

Recent studies showed that a combination of carbohydrate and protein was more effective than carbohydrate alone for replenishing muscle glycogen after exercise. However, it remains to be unclear whether the source or degree of hydrolysis of dietary protein influences post-exercise glycogen accumulation. The aim of this study was to compare the effect of dietary protein type on glycogen levels in the post-exercise phase, and to investigate the effects of post-exercise carbohydrate and protein supplementation on phosphorylated enzymes of Akt/PKB and atypical PKCs. Male Sprague-Dawley rats, trained for 3 days, swam with a 2% load of body weight for 4 h to deplete skeletal muscle glycogen. Immediately after the glycogen-depleting exercise, one group was killed, whereas the other groups were given either glucose or glucose plus protein (whey protein, whey protein hydrolysates (WPH), casein hydrolysates or branched-chain amino acid (BCAA) solutions. After 2 h, the rats were killed, and the triceps muscles quickly excised. WPH caused significant increases in skeletal muscle glycogen level (5.01 +/- 0.24 mg/g), compared with whey protein (4.23 +/- 0.24 mg/g), BCAA (3.92 +/- 0.18 mg/g) or casein hydrolysates (2.73 +/- 0.22 mg/g). Post-exercise ingestion of glucose plus WPH significantly increased both phosphorylated Akt/PKB (131%) and phosphorylated PKCzeta (154%) levels compared with glucose only. There was a significant positive correlation between skeletal muscle glycogen content and phosphorylated Akt/PKB (r = 0.674, P < 0.001) and PKCzeta (r = 0.481, P = 0.017). Post-exercise supplementation with carbohydrate and WPH increases skeletal muscle glycogen recovery by activating key enzymes such as Akt/PKB and atypical PKCs.

Development and validation of a liquid chromatography tandem mass spectrometry method for simultaneous determination of four anthocyanins in human plasma after black currant anthocyanins ingestion.

Black currant anthocyanins consist of delphinidin-3-glucoside (1), delphinidin-3-rutinoside (2), cyanidin-3-glucoside (3), and cyanidin-3-rutinoside (4). A liquid chromatography tandem mass spectrometry method for simultaneous determination of four anthocyanins in human plasma was developed and validated. Samples were prepared using solid phase extraction, followed by chromatographic separation with a reverse phase C(18) column with gradient elution using mobile phases containing water, acetonitrile, and formic acid. The quantification of four anthocyanins was determined by multiple reaction monitoring using electrospray ionization. The method showed good selectivity, sensitivity (limits of quantification for four anthocyanins were 0.2 nmol/L), linearity (0.2-20 nmol/L; r > 0.999), intra- and interday precision, accuracy (<14%), and recovery (62.5-85.7%). Analyte stability was investigated in detail. This method was successfully applied to the determination of delphinidin-3-glucoside (1), delphinidin-3-rutinoside (2), cyanidin-3-glucoside (3), and cyanidin-3-rutinoside (4) concentrations in human plasma after ingestion of a single dose of black currant anthocyanins (87.9 micromol (58.8 mg) total anthocyanins).

Dietary orotic acid increases 1 ,2-diacylglycerol level and lowers superoxide dismutase activity in rat liver.

The effects of the dietary addition of orotic acid were studied on lipid levels in the rat liver and serum, 1,2-diacylglycerol levels in some organs, activities of antioxidant liver enzymes (superoxide dismutase, glutathione peroxidase, and catalase), and serum enzyme activities (ornithine carbamoyltransferase and alanine aminotransferase), after feeding for 0, 7, 14, and 21 d, respectively. Rats on the orotic acid diet accumulated more liver total lipids, triacylglycerol, and phospholipids than those on the basal diet. However, the levels of serum triacylglycerol and phospholipids of those rats were markedly decreased after 7, 14, and 21 d on the diet. Dietary orotic acid increased the 1,2-diacylglycerol levels in the liver of rats fed for 14 or 21 d, but not in the ileum of small intestine, vastus lateralis muscle, and heart. The addition of orotic acid lowered the activities of liver total and Cu,Zn-superoxide dismutase after feeding for 7, 14, and 21 d. The serum ornithine carbamoyltransferase activity after 14, and 21 d and that of serum alanine aminotransferase after 7, 14, and 21 d were increased. These data suggested that the increase in the activities of serum enzymes tested may result from liver damage induced by the marked accumulation of liver lipids and possibly from the increased superoxide anion because of the decreased activities of hepatic superoxide dismutase by orotic acid feeding.