Nucleotide and polyamine levels in colostrum and mature milk in relation to maternal atopy and atopic development in the children

Activation of whole body by high levels of polyamine intake in rats

Polyamines are important to the survival and activation of organs and tissues via a homeostatic cell-metabolic process, and the polyamine content in cytoplasm decreases with aging. Decreases in cellular polyamine have been known to augment mutagenesis and cell death. Thus, supplementary polyamine in food is important to the prevention of aging. Here we show the anti-aging effects of oral intake of polyamine using luciferase-transgenic rats. Healthy rats, 10–12 weeks old, were given foods containing 0.01% and 0.1% (w/w) of polyamine, as compared a control food without polyamine, for 4 weeks. Using a bioimaging system, the photon intensities seen in the whole bodies and livers of rats consuming 0.1% of polyamine in food were stronger than those in rats consuming 0.01% and 0% of polyamine. However, there were no differences between groups in other characteristics, such as liver damage and body weight. In conclusion, we found that polyamine intake can activate cells throughout the whole body, providing an anti-aging effect.

The Determinants of the Human Milk Metabolome and Its Role in Infant Health

Human milk is needed for optimal growth as it satisfies both the nutritional and biological needs of an infant. The established relationship between breastfeeding and an infant’s health is attributable to the nutritional and non-nutritional, functional components of human milk including metabolites such as the lipids, amino acids, biogenic amines and carbohydrates. These components have diverse roles, including protecting the infant against infections and guiding the development of the infant’s immature immune system. In this review, we provide an in-depth and updated insight into the immune modulatory and anti-infective role of human milk metabolites and their effects on infant health and development. We also review the literature on potential determinants of the human milk metabolome, including maternal infectious diseases such as human immunodeficiency virus and mastitis.

Temporal variations of nucleosides and nucleotides in rabbit milk

Nucleotides and nucleosides have a preeminent role in physiological and biochemical processes for newborns, the major source of these during early development is the breast milk. Different biomolecules exhibit daily fluctuations in maternal milk that could transfer temporal information that synchronize newborn circadian system. As a first approach, we characterized the diurnal profile of nucleotides and nucleosides contained in maternal milk of rabbits during the first week of lactation. It is possible that some nucleosides, such as adenosine, play a relevant role in setting up the emerging circadian rhythmicity, whereas uridine and guanosine could participate in the maintenance of rhythmicity.

Chemistry of Human Breast Milk-A Comprehensive Review of the Composition and Role of Milk Metabolites in Child Development

Early nutrition has an enormous influence on a child's physiological function, immune system maturation, and cognitive development. Human breast milk (HBM) is recognized as the gold standard for human infant nutrition. According to a WHO report, breastfeeding is considered as an unequaled way of providing ideal food to the infant, which is required for his healthy growth and development. HBM contains various macronutrients (carbohydrates, proteins, lipids, and vitamins) as well as numerous bioactive compounds and interactive elements (growth factors, hormones, cytokines, chemokines, and antimicrobial compounds. The aim of this review is to summarize and discuss the current knowledge about metabolites, which are the least understood components of HBM, and their potential role in infant development. We focus on small metabolites (<1500 Da) and characterize the chemical structure and biological function of polar metabolites such as human milk oligosaccharides, nonprotein molecules containing nitrogen (creatine, amino acids, nucleotides, polyamines), and nonpolar lipids. We believe that this manuscript will provide a comprehensive insight into a HBM metabolite composition, chemical structure, and their role in a child's early life nutrition.

Raman spectroscopy combined with a support vector machine for differentiating between feeding male and female infants mother's milk

This study presents differentiation in milk samples of mother's feeding male and female infants using Raman spectroscopy combined with a support vector machine (SVM). Major differences have been observed in the Raman spectra of both types of milk based on their chemical compositions. Overall, it has been found that milk samples of mother's having a female infant are richer in fatty acids, phospholipids, and tryptophan. In contrast, milk samples of mother's having a male infant contain more carotenoids and saccharides. Principal component analysis and SVM further highlighted the differences between the two groups on the basis of differentiating features obtained from their Raman spectra. The SVM model with two different kernels, i.e. polynomial kernel function (order-2) and Gaussian radial basis function (RBF sigma-2), are used for gender based milk differentiations. The performance of the proposed model in terms of accuracy, precision, sensitivity, and specificity using the polynomial kernel function of order-2 have been found to be 86%, 88%, 85% and 88%, respectively.

NMR-based metabolite profiling of human milk: A pilot study of methods for investigating compositional changes during lactation

Low-molecular-weight metabolites in human milk are gaining increasing interest in studies of infant nutrition. In the present study, the milk metabolome from a single mother was explored at different stages of lactation. Metabolites were extracted from sample aliquots using either methanol/water (MeOH/H2O) extraction or ultrafiltration. Nuclear magnetic resonance (NMR) spectroscopy was used for metabolite identification and quantification, and multi- and univariate statistical data analyses were used to detect changes over time of lactation. Compared to MeOH/H2O extraction, ultrafiltration more efficiently reduced the interference from lipid and protein resonances, thereby enabling the identification and quantification of 36 metabolites. The human milk metabolomes at the early (9-24 days after delivery) and late (31-87 days after delivery) stages of lactation were distinctly different according to multi- and univariate statistics. The late lactation stage was characterized by significantly elevated concentrations of lactose, choline, alanine, glutamate, and glutamine, as well as by reduced levels of citrate, phosphocholine, glycerophosphocholine, and N-acetylglucosamine. Our results indicate that there are significant compositional changes of the human milk metabolome also in different phases of the matured lactation stage. These findings complement temporal studies on the colostrum and transitional metabolome in providing a better understanding of the nutritional variations received by an infant.

Lower polyamine levels in breast milk of obese mothers compared to mothers with normal body weight

BACKGROUND

Obesity is associated with risks for mother and infant, and the mothers' dietary habits influence breast milk composition. Polyamines are secreted in breast milk and are essential for the regulation of intestinal and immune function in newborns and infants. The present study aimed to investigate the level of polyamines in human milk obtained from obese and normal weight mothers at different times of lactation.

METHODS

Breast milk from 50 mothers was obtained at day 3, and at 1 and 2 months after delivery. The mothers had normal body weight [body mass index (BMI) < 25 kg m(-2) ] or were obese (BMI > 30 kg/m(2) ). A subgroup of obese mothers participated in a weight reduction programme during pregnancy. Polyamines were analysed using high-performance liquid chromatography.

RESULTS

The total polyamine content was significantly lower at all times in breast milk from obese mothers compared to milk from controls. Spermine levels did not differ between groups at any time in contrast to the levels of putrescine and spermidine. Putrescine concentrations were highest on day 3 and spermidine and spermine were highest at 1 month of lactation. The obese mothers, who received dietary advice during pregnancy based on the Nordic Nutrition Recommendations, had higher concentrations of putrescine and spermidine in their milk than the obese mothers without any intervention.

CONCLUSIONS

Polyamine concentrations were lower in breast milk from obese mothers compared to mothers with a normal weight. General dietary intervention in obese mothers increased the polyamine levels, suggesting that the low levels in obesity were at least partly associated with food habits. However, the consistency of spermine suggests a special metabolic function of this polyamine.

Polyamines in human breast milk for preterm and term infants

Maternal milk is the first source of exogenous polyamines for the newborn. Polyamines modulate gut maturation in neonates, but no studies are available on polyamine concentration in human milk of preterm babies, even though they could be important for their immature gut. The present study aimed to determine polyamine concentration in human breast milk of mothers with preterm or term infants during the first month of lactation. Human milk samples were obtained during the first month of lactation from twenty-seven mothers with preterm babies and twelve mothers with babies born at term. The polyamine concentration in human milk was quantified by HPLC. During the first month of lactation, the total polyamine concentration was significantly higher in preterm milk than in term milk samples (7590 (sd 4990) v. 4660 (sd 4830) nmol/l, respectively (P =0·034)), as well as individual polyamine concentrations. Polyamine concentration in mature milk for preterm babies was significantly higher than that in mature milk for babies at term, and a similar trend was observed in colostrum and transition human milk. The spermidine/spermine ratio was higher in transition milk in preterm v. term samples, while in mature milk, the ratio was significantly lower in preterm than in term babies. In conclusion, the polyamine concentration was significantly higher in human milk for preterm than for term infants. This and the different spermidine/spermine ratios could influence the gut development of premature babies.

Adenosine 5'-triphosphate (ATP) supplements are not orally bioavailable: a randomized, placebo-controlled cross-over trial in healthy humans

BACKGROUND

Nutritional supplements designed to increase adenosine 5'-triphosphate (ATP) concentrations are commonly used by athletes as ergogenic aids. ATP is the primary source of energy for the cells, and supplementation may enhance the ability to maintain high ATP turnover during high-intensity exercise. Oral ATP supplements have beneficial effects in some but not all studies examining physical performance. One of the remaining questions is whether orally administered ATP is bioavailable. We investigated whether acute supplementation with oral ATP administered as enteric-coated pellets led to increased concentrations of ATP or its metabolites in the circulation.

METHODS

Eight healthy volunteers participated in a cross-over study. Participants were given in random order single doses of 5000 mg ATP or placebo. To prevent degradation of ATP in the acidic environment of the stomach, the supplement was administered via two types of pH-sensitive, enteric-coated pellets (targeted at release in the proximal or distal small intestine), or via a naso-duodenal tube. Blood ATP and metabolite concentrations were monitored by HPLC for 4.5 h (naso-duodenal tube) or 7 h (pellets) post-administration. Areas under the concentration vs. time curve were calculated and compared by paired-samples t-tests.

RESULTS

ATP concentrations in blood did not increase after ATP supplementation via enteric-coated pellets or naso-duodenal tube. In contrast, concentrations of the final catabolic product of ATP, uric acid, were significantly increased compared to placebo by ~50% after administration via proximal-release pellets (P = 0.003) and naso-duodenal tube (P = 0.001), but not after administration via distal-release pellets.

CONCLUSIONS

A single dose of orally administered ATP is not bioavailable, and this may explain why several studies did not find ergogenic effects of oral ATP supplementation. On the other hand, increases in uric acid after release of ATP in the proximal part of the small intestine suggest that ATP or one of its metabolites is absorbed and metabolized. Uric acid itself may have ergogenic effects, but this needs further study. Also, more studies are needed to determine whether chronic administration of ATP will enhance its oral bioavailability.

Strategies to prevent or reduce allergic disease

The need for allergy prevention strategies has never been greater. Surging rates of food allergy and eczema are now adding to the already substantial burden of asthma and respiratory allergic diseases. The parallel rise in many other immune diseases suggests that the developing immune system is highly vulnerable to modern environmental changes. These strong environmental pressures may be one reason why simple allergen avoidance strategies have not been successful. Another more recent strategy to curtail the allergy epidemic has been to identify factors associated with modern lifestyle that may be causally linked with allergic disease, in an attempt to restore more favourable conditions for immune tolerance during early development. More hygienic conditions and disruption of microbial exposure have prompted strategies to restore this balance using probiotic and prebiotic supplements. Modern dietary changes linked with allergic diseases have prompted supplementation studies to assess the preventive merits of specific immunomodulatory dietary nutrients such as polyunsaturated fatty acids. Other nutrients such as antioxidants, folate, and vitamin D are also currently under investigation. Modern environmental pollutants have also been associated with adverse effects on immune development and the risk of disease. While many of these avenues have provided some promise, they have not yet translated into specific recommendations. Current evidence-based guidelines for allergy prevention remain limited to avoidance of cigarette smoke, promotion of breastfeeding and the use of hydrolysed formula when breastfeeding is not possible. Allergen avoidance strategies have been largely removed from most guidelines. It is hoped that a number of ongoing studies will help provide clearer recommendations around the use of probiotics, prebiotics, specific dietary nutrients and the role of early introduction of allergenic foods for the promotion of tolerance. Despite the current uncertainties, prevention remains the best long-term strategy to reduce the growing burden of allergic disease.

Profile of nucleotides and nucleosides in Taiwanese human milk

BACKGROUND

Human milk-borne nucleotides and their related metabolic products have been reported to have important physiological roles in breast-fed infants. The purpose of this study was to measure the concentrations of free nucleotides and nucleosides in human milk from Taiwanese women.

METHODS

A total of 24 individual milk specimens were collected from women in Taipei and Kaohsiung, at four stages of lactation. Vegetarian or non-vegetarian dietary patterns were recorded. The samples were analyzed for nucleotides and nucleosides by high-performance liquid chromatography.

RESULTS

The mean (±standard deviation) free nucleotide and nucleoside concentrations in Taiwanese human milk were 213.13 ± 76.26 μmol/L and 16.38 ± 7.11 μmol/L. The predominant nucleotide was cytidine diphosphate for almost all samples, regardless of the location, stage of lactation, or dietary status of the subjects. Overall, the mean concentrations of cytidine diphosphate, cytidine monophosphate, uridine monophosphate, guanosine monophosphate, adenosine monophosphate, and inosine monophosphate, in milk samples were 129.86 μmol/L, 49.10 μmol/L, 5.60 μmol/L, 0.82 μmol/L, 2.96 μmol/L, and 25.25 μmol/L, respectively (equivalent to 61.0%, 23.1%, 2.6%, 0.4%, 1.0%, and 11.9% of free nucleotide composition). In free nucleosides, cytidine and uridine were predominant during all stages of lactation. The average concentrations of cytidine, uridine, adenosine, guanosine, and inosine, in milk samples were 9.25 μmol/L, 6.33 μmol/L, 0.18 μmol/L, 0.36 μmol/L, and 0.23 μmol/L, respectively (equivalent to 56.5%, 38.7%, 1.1%, 2.2%, and 1.4% of free nucleoside composition). Comparing vegetarian and non-vegetarian statuses, it was found that the total free nucleotide concentration was high in the vegetarian group (p=0.037).

CONCLUSION

Our data showed a wide range of concentrations of individual nucleotides and nucleosides in Taiwanese human milk. Unique dietary status could affect the nucleotide and nucleoside levels in human milk, especially the nucleotides in our study. However, the mechanism of modulation of nucleotide and nucleoside levels in human milk is not clear.

Nucleotides and nucleosides in ovine and caprine milk during lactation

The aim of this study was to determine the nucleoside and nucleotide content in ovine and caprine milks at the colostral, transitional, and mature stages of lactation. Samples from 18 dairy sheep and 18 dairy goats were collected at 1, 2, 3, 4, 5, and 15 d postpartum. Separation and quantitation of the 5'-nucleotides (NT) and the nucleosides (NS) was performed by reverse phase HPLC. For each compound measured, considerable interindividual variation was recorded in both species of milk. The total NS content ranged from 57 to 132 micromol/L and from 54 to 119 micromol/L in ovine and caprine milk, respectively. The major NS identified in both species of milk was uridine, representing more than 60% of the total NS pool. The mean levels of inosine and guanosine were comparable between ewe and goat milk. Instead, the mean level of cytidine across the sampling period was much higher in ewe milk (11.9 micromol/L compared with 4.5 micromol/L in goat milk) and exhibited a peak value on the fourth day of lactation. The adenosine content was at least 3-fold higher in caprine milk compared with its ovine counterpart. The total NS and orotic acid contents did not differ significantly between the 2 species. However, in the case of total NT content, interspecies differences were significant, with NT levels ranging from 294 to 441 micromol/L in ovine milk and from 166 to 366 micromol/L in caprine milk. The NT content in colostrum (1-3 d) of both species was higher than in mature milk (15 d), and uridine monophosphate was the dominant NT in all samples.

Effects of 5'-uridylic acid feeding on postprandial plasma concentrations of metabolites and metabolic hormones in pre-weaning goats

5'-Uridylic acid (UMP), which is present at high concentrations in cow's colostrum, has been shown to cause a reduction in increased plasma levels of insulin and glucose after ingestion of milk replacer in pre-weaning calves. However, the precise mechanisms of UMP action have not been investigated, and its action has not been investigated in other pre-weaning ruminants. In order to demonstrate whether UMP causes changes in postprandial metabolic and hormonal parameters in pre-weaning goats, 11 Saanen kids were given milk replacer (twice a day) without (n = 5) or with (n = 6) UMP (1 g for each meal, 2 g/day for each head) for 14 days. Analysis of blood samples taken in the morning of day 14 demonstrated that the feeding of milk replacer with UMP abolished the significant changes in postprandial plasma glucose, NEFA, GH and insulin concentrations induced by feeding of milk replacer alone, and demonstrated a tendency to increase IGF-I levels. However, there was no significant difference between the two groups at any sampling time. We conclude that UMP feeding with milk replacer showed a tendency to blunt the postprandial changes in levels of some plasma metabolites and hormones that are induced by replacer alone in pre-weaning goats.

The possible role of human milk nucleotides as sleep inducers

Breast-milk contains a potent mixture of diverse components, such as the non-protein nitrogen fraction which includes nucleotides, whose variation in levels is evident throughout lactation. In addition, these substances play an important role in sleep homeostasis. In the present study, human milk samples were analyzed using a capillary electrophoresis system. The rhythmicity of each nucleotide was studied by cosinor analysis. It was found that the nucleotides 5'AMP, 5'GMP, 5'CMP, and 5'IMP have significant (P < 0.05) circadian rhythms, the acrophases of the first two being during the night, and of the latter two during the day. While 5'UMP did not show a clear circadian rhythm, there was an increase in its levels at night. In conclusion, the rise in nocturnal levels of 5'AMP, 5'GMP, and 5'UMP could be involved in inducing the 'hypnotic' action of breast-milk at night in the infant.

Composition of the non-protein nitrogen fraction of goat whole milk powder and goat milk-based infant and follow-on formulae

The non-protein nitrogen fraction of goat whole milk powder and of infant and follow-on formulae made from goat milk was characterized and compared with cow milk powder and formulae. Goat milk infant formula contained 10% non-protein nitrogen, expressed as a proportion of total nitrogen, compared with 7.1% for cow milk formula. Goat follow-on formula contained 9.3% and cow 7.4% non-protein nitrogen. Urea, at 30%, was quantitatively the most abundant component of the non-protein nitrogen fraction of goat milk and formulae, followed by free amino acids at 7%. Taurine, glycine and glutamic acid were the most abundant free amino acids in goat milk powders. Goat milk infant formula contained 4 mg/100 ml total nucleotide monophosphates, all derived from the goat milk itself. Goat milk has a very different profile of the non-protein nitrogen fraction to cow milk, with several constituents such as nucleotides at concentrations approaching those in human breast milk.

Exogenous nucleosides accelerate differentiation of rat intestinal epithelial cells

Several studies have reported differing data on the effect of exogenous nucleosides and nucleotides on the proliferation and differentiation in various intestinal cell lines and explants. To study whether exogenous nucleosides modulate intestinal cell differentiation, IEC-6 cells were differentiated in the presence or absence of a nucleoside mixture (cytidine, uridine, guanosine and inosine, 30 microM each), and the concentrations of nucleoside derivatives were determined by HPLC. Cell differentiation was assessed by electron microscopy, alkaline phosphatase activity and Rnd3 gene expression. The present results showed that uridine, guanosine and inosine were cleared from culture media (up to 32, 63 and 100 % in proliferating cells, and 31, 80 and 94 % in differentiated cells, respectively) whereas cytidine concentrations increased. Differentiation of IEC-6 cells was associated with a significant increase in intracellular nucleotide concentrations. Clearance of nucleosides correlated with a significant increase in the intracellular nucleotide pool in proliferating and differentiated IEC-6 cells. Intracellular guanosine nucleotides increased 2.5- and 5-fold in nucleoside-supplemented proliferating and differentiated cells, respectively. At 24 h, nucleoside-supplemented differentiated IEC-6 cells had significantly higher energy charge and GTP levels than non-supplemented ones. These modifications paralleled changes in cell differentiation as indicated by increased alkaline phosphatase activity, prolonged microvilli formation and accelerated down-regulation of Rnd3 gene expression. The present findings suggest that exogenous nucleosides were selectively taken up by IEC-6 cells, increased the intracellular nucleotide pool, GTP and energy charge, and favoured cell morphological and functional changes during differentiation.

Biological significance of dietary polyamines

Polyamines are classically known by their names of putrescine, spermine, and spermidine. They are synthesized endogenously from ornithine and are interconvertible. In addition, an exogenous supply of polyamines is provided by dietary intake and by intestinal absorption from the products of bacterial metabolism. Polyamine uptake occurs almost entirely in the gut, and afterward the various forms are metabolized in different tissues under the strict regulation of ornithine decarboxylase, which is the first enzyme involved in their synthesis. Polyamines are eliminated from the organism by means of oxidation reactions, appearing in urine in all their metabolic forms. Polyamines play an important role in regulating cell growth and proliferation, the stabilization of negative charges of DNA, RNA transcription, protein synthesis, apoptosis, and the regulation of the immune response. They are components of breast milk and might be important in neonatal gut maturation, for which reason the possible supplementation of infant formulas with these compounds is under study.

Oral administration of uridylic acid increases plasma leptin, but suppresses glucose and non-esterified fatty acid concentrations in rats

Nucleic acids have been known to have biological effects on the digestive and immune systems, although less attention has been paid to the action on metabolism. In the present study, in order to investigate the effects of oral ingestion of uridylic acid (5'-uridine monophosphate, 5'-UMP) on hormonal and metabolic levels, we measured changes in the plasma concentrations of leptin, insulin, glucose, non-esterified fatty acids (NEFA), weights of the liver and abdominal fat and fat accumulation in the liver and M. gastrocnemius in male rats. Intragastric administration of 5'-UMP via a stomach tube at a dose of 44 mg/day for 7 days slightly (P=0.098) blunted the body weight gain without causing a significant change in food intake. The administration significantly reduced the plasma concentrations of glucose (P=0.004) and NEFA (P=0.004), whereas it significantly increased (P=0.03) plasma leptin concentration. The weights of perirenal (but not epididymal) fat (P=0.083) and the liver (P=0.061) were slightly increased. The triacylglyceride concentration in M. gastrocnemius was slightly increased (P=0.097), although the muscle weight was not significantly changed (P=0.197). In summary, acute oral administration of 5'-UMP was effective in the rat in reducing plasma concentrations of glucose and NEFA, an effect that was accompanied by an elevated plasma leptin concentration.

Analysis of polyamines as markers of (patho)physiological conditions

The aliphatic polyamines, putrescine, spermidine and spermine, are normal cell constituents that play important roles in cell proliferation and differentiation. The equilibrium between cellular uptake and release and the balanced activities of biosynthetic and catabolic enzymes of polyamines are essential for normal homeostasis in the proliferation and functions of cells and tissues. However, the intracellular polyamine content increases in hyperplastic or neoplastic growth. Although the involvement of polyamines in physiological and pathological cell proliferation and differentiation has been well established, the role they play is quite different in relation to cell systems and animal models and is dependent on inducer agents and stimuli. Also, the experimental procedures used to deplete polyamines have been shown to influence the cell responses. In this paper, the assay methods currently in use for polyamines are reviewed and compared with respect to sensitivity, reproducibility and applicability to routine analysis. The relevance of polyamine metabolism and the uptake/release process in many physiological and pathological processes is highlighted, and the cellular polyamine pathways are discussed in relation to the possible diagnostic and therapeutic significance of these mediators.

Dietary polyamines and non-neoplastic growth and disease

This review presents the data that are now available concerning the effects of dietary polyamines at either postnatal or adult stages in non-neoplastic growth and disease. Polyamines provided by food have a potential role in growth and development of the digestive system in neonatal mammals (and fishes). In humans, this property could be of importance in preventing the appearance of food allergies. Dietary polyamines also seem necessary for the maintenance of normal growth and general properties of adult digestive tract. Their possible therapeutic effects have been investigated in gastric, intestinal, and, more recently, whole-body healing.

Determination of polyamines in human saliva by high-performance liquid chromatography with fluorescence detection

A high-performance liquid chromatographic method for the determination of polyamines (spermine, spermidine and putrescine) in human saliva was developed. This method is based on pre-column derivatization with o-phthaldialdehyde (OPA). The derivatives were separated on a Nucleosil ODS column (250x4.6 mm I.D.; 5 microm). The gradient elution was performed with two mobile phases A (water) and B (methanol) at a flow rate of 0.8 ml/min. The column eluate was monitored by fluorescence detection (excitation, 360 nm; emission, 510 nm). The within- and between-assay coefficients of variation for all the compounds were below 5%. The detection limits for spermine, spermidine and putrescine were 0.04, 0.05 and 0.06 nmol/ml, respectively. The recovery was greater than 90%. Our analytical technique requires neither preliminary extraction with an organic solvent, nor long multi-step procedures. For saliva samples, this is a simple, rapid and highly reproducible method that can be easily applied to the routine determination of salivary polyamines, whose levels increase early in several pathological conditions.