Polyunsaturated fatty acids in human milk and their role in early infant development

Effect of Holder Pasteurization, Mode of Delivery, and Infant's Gender on Fatty Acid Composition of Donor Breast Milk

Breast milk (BM) plays a crucial role in providing essential fatty acids (FA) and energy for the growing infant. When the mother's own BM is not available, nutritional recommendations suggest donor milk (DM) in clinical and home practices. BM was collected from a variety of donor mothers in different lactation stages. Holder pasteurization (HoP) eliminates potential contaminants to ensure safety. FA content of BM samples from the Breast Milk Collection Center of Pécs, Hungary, were analyzed before and after HoP. HoP decreases the level of C6:0, C8:0, C14:1n-5c, C18:1n-9c, C18:3n-6c, C18:3n-3c, and C20:4n-6c in BM, while C14:0, C16:0, C18:1n-9t, C22:0, C22:1n-9c, C24:0, C24:1n-9c, and C22:6n-3c were found in elevated concentration after HoP. We did not detect time-dependent concentration changes in FAs in the first year of lactation. BM produced for girl infants contains higher C20:2n-6c levels. In the BM of mothers who delivered via cesarean section, C12:0, C15:0, C16:0, C17:0, C18:0, C18:1n-9t, C22:1n-9c levels were higher, while C18:2n-6c, C22:0, C24:0, and C22:6n-3c concentrations were lower compared to mothers who gave birth spontaneously. FAs in BM are constant during the first year of lactation. Although HoP modifies the concentration of different FAs, pasteurized DM provides essential FAs to the developing infant. Current data providing information about the FA profile of BM gives origination to supplementation guidelines.

Maternal childhood trauma is associated with offspring body size during the first year of life

Maternal childhood trauma (MCT) is an important factor affecting offspring size at birth. Whether the effect of MCT persists during the subsequent development remains unclear. We present the results of a semi-longitudinal investigation examining the physical growth of infants born to mothers with high (HCT) and low (LCT) childhood trauma during the first year of life. One hundred healthy mother-infant dyads were included based on following criteria: exclusive breastfeeding, birth on term with appropriate weight for gestational age. MCT was assessed using the Early Life Stress Questionnaire. The weight, length, and head circumference of the infant were taken at birth, 5 and 12 months postpartum. Separate MANCOVA models were run for infant size at each age. We found an association between MCT and infant size at 5 and 12 months. The children of mothers with HCT had higher weight and greater head circumference than the children of mothers with LCT. These results suggest that MCT might contribute to developmental programming of offspring growth during the first year of life. From an evolutionary perspective, the larger size of HCT mother's offspring might represent an adaptation to potentially harsh environmental conditions. This effect might be mediated by epigenetic changes to DNA and altered breast milk composition.

Fatty Acid Composition of Milk from Mothers with Normal Weight, Obesity, or Gestational Diabetes

Gestation and the neonatal period are crucial periods in infant development. Many components of breast milk, including fatty acids, play an important role in strengthening the immune system. The aim of our research was to evaluate the fatty acid profiles of milk from 69 mothers, including subjects having a normal weight, obesity, or gestational diabetes. For the analyses, we used gas chromatography (GC) with flame ionization detection (FID) and GC coupled with mass spectrometry (GC/MS). The main fatty acids found in breast milk were palmitic acid (C16:0; 26-28%), linoleic acid (C18:2; 23-28%), and α-linolenic acid linoleic acid (C18:3; 15-17%), followed by myristic acid (C14:0; 5-8%), lauric acid (C12:0; 4-6%) and stearic acid (C18:0; 4-5%). The average breakdown of fatty acids was 50% saturated, 44% polyunsaturated, and 6% monounsaturated. Breast milk samples were classified using principal component analysis and linear discriminant analysis. Results showed that milk from the two major groups of obese and normal body mass index (BMI) could be distinguished with an accuracy of 89.66%. Breast milk samples of Hungarian and Ukrainian mothers showed significant differences based on the fatty acid composition, which variations are attributable to the mothers' dietary habits.

Effects of Maternal Exclusion Diet for Infants Suspected Food Allergy on Fatty Acid Composition in Breast Milk

Background: Levels of fatty acid (FA) in breast milk (BM) may vary depending on the maternal diet. This study aimed to explore FA composition in BM of lactating women following dietary restrictions due to infant allergic conditions. Materials and Methods: Thai lactating mothers of term infants who were on exclusion diets were recruited. Mature BM was collected before and after a period (at least 2 weeks) of dietary restriction. FA in BM was analyzed by gas chromatography-mass spectrometry. Results: Fifty lactating women 33.7 ± 3.6 years of age were enrolled. Thirty-three percent of the lactating mothers restricted more than eight food items. Most common dietary restriction were cow's milk (88%) and eggs (74%). After the period of dietary exclusion, total polyunsaturated FA showed no significant change, while saturated FA (SFA) declined, and monounsaturated FA (MUFA) increased. A decrease in fat intake was associated with an increase in arachidonic acid (ARA) and docosahexaenoic acid (DHA) content in BM (r = -0.37, r = -0.36; p < 0.05). However, a rise in ARA, eicosapentaenoic acid (EPA), and DHA intake was associated with an increase in linoleic acid and EPA in BM, respectively (r = 0.38, r = 0.55 and r = 0.41; p < 0.05). Infant weight-for-age z-score did not significantly change after the period of maternal dietary exclusion. Conclusion: Maternal exclusion diet resulted in lower SFA and higher MUFA composition in BM. Further study should explore the long-term outcomes of maternal dietary restriction on infant and child health.

Evaluation of Breast Milk Macronutrient Content in Preeclamptic Mothers

Background: Preeclampsia remains among the leading causes of maternal and perinatal morbidity and mortality worldwide. This study aimed to evaluate the macronutrient content of colostrum in mothers with preeclampsia. Materials and Methods: Women who delivered by cesarean section at ≤37 weeks of gestation were included in the study. Fresh colostrum samples were collected by manual expression on postpartum days 2 and 4 and were analyzed using a mid-infrared human milk analyzer. Demographic characteristics of the patients were recorded. The protein, fat, carbohydrate, and energy composition of the milk samples were compared between mothers with and without preeclampsia. Results: A total of 58 colostrum samples (25 preeclampsia, 33 nonpreeclampsia) were analyzed. The median gestational age of the infants was similar in both groups (32 versus 33 weeks; p > 0.05). There were also no differences between the groups in terms of maternal age, maternal body mass index, maternal weight gain during pregnancy, and infant gender. Median protein, fat, and carbohydrate levels in the colostrum of the preeclamptic mothers were 2.2, 2.1, and 6.3 g/dL, respectively, compared with 1.8, 2.4, and 6.2 g/dL in the nonpreeclamptic mothers, respectively. Although the colostrum of preeclamptic mothers had higher protein content and lower fat content, the difference was not statistically significant. Carbohydrate and energy contents were similar in both groups. Conclusions: The presence of preeclampsia does not cause a significant change in the macronutrient composition of mother's milk. Analyses of micronutrients at different lactation stages in larger samples are needed.

Near-Infrared Sensors for Onsite and Noninvasive Quantification of Macronutrients in Breast Milk

Breast milk is an optimal food that covers all the nutritional needs of the newborn. It is a dynamic fluid whose composition varies with lactation period. The neonatal units of hospitals have human milk banks, a service that analyzes, stores, and distributes donated human milk. This milk is used to feed premature infants (born before 32 weeks of gestation or weighing less than 1500 g) whose mothers, for some reason, cannot feed them with their own milk. Here, we aimed to develop near-infrared spectroscopy (NIRS) measures for the analysis of breast milk. For this purpose, we used a portable NIRS instrument scanning in the range of 1396-2396 nm to collect the spectra of milk samples. Then, different chemometrics were calculated to develop 18 calibration models with and without using derivatives and the standard normal variate. Once the calibration models were developed, the best treatments were selected according to the correlation coefficients (r²) and prediction errors (SECVs). The best results for the assayed macronutrients were obtained when no pre-treatment was applied to the NIR spectra of fat (r² = 0.841, SECV = 0.51), raw protein (r² = 0.512, SECV = 0.21), and carbohydrates (r² = 0.741, SECV = 1.35). SNV plus the first derivative was applied to obtain satisfactory results for energy (r² = 0.830, SECV = 9.60) quantification. The interpretation of the obtained results showed the richness of the NIRS spectra; moreover, the presence of specific bands for fat provided excellent statistics in quantitative models. These results demonstrated the ability of portable NIRS sensors in a methodology developed for the quality control of macronutrients in breast milk.

Total Fatty Acid and Polar Lipid Species Composition of Human Milk

Human milk lipids are essential for infant health. However, little is known about the relationship between total milk fatty acid (FA) composition and polar lipid species composition. Therefore, we aimed to characterize the relationship between the FA and polar lipid species composition in human milk, with a focus on differences between milk with higher or lower milk fat content. From the Norwegian Human Milk Study (HUMIS, 2002–2009), a subset of 664 milk samples were analyzed for FA and polar lipid composition. Milk samples did not differ in major FA, phosphatidylcholine, or sphingomyelin species percentages between the highest and lowest quartiles of total FA concentration. However, milk in the highest FA quartile had a lower phospholipid-to-total-FA ratio and a lower sphingomyelin-to-phosphatidylcholine ratio than the lowest quartile. The only FAs associated with total phosphatidylcholine or sphingomyelin were behenic and tridecanoic acids, respectively. Milk FA and phosphatidylcholine and sphingomyelin species containing these FAs showed modest correlations. Associations of arachidonic and docosahexaenoic acids with percentages of phosphatidylcholine species carrying these FAs support the conclusion that the availability of these FAs limits the synthesis of phospholipid species containing them.

The Fatty Acid Species and Quantity Consumed by the Breastfed Infant Are Important for Growth and Development

The fatty acids (FAs) of human milk (HM) are the building blocks of the HM lipidome, contributing to infant health and development; however, this has not been comprehensively characterised with respect to infant intake. Eighteen Western Australian mother-infant dyads provided monthly longitudinal HM samples during six months of exclusive breastfeeding. Monthly anthropometric measurements, health data and basic maternal food frequency data were also collected. At three months, infant 24 h milk intake and total lipid intake were measured. The FA profile was analysed using gas chromatography-mass spectrometry. Linear regression and Pearson's correlation were used to identify associations between HM FA composition, HM FA intake, maternal characteristics and infant growth and developmental outcomes. Mean infant intake of total lipids was 29.7 ± 9.4 g/day. HM FA composition exhibited wide variation between dyads and throughout lactation. Infant intake of a number of FAs, including C15:0, C18:1, C18:2 and C20:3, was positively related to infant growth (all p < 0.001). There were no relationships detected between C22:5 and C20:5 and infant head circumference. Infant total lipid intake and the infant intake of many FAs play essential roles in infant growth and development. This study highlights the important relationships of many HM FAs not previously described, including C15:0 and C18:2 species. Infant outcomes should be considered in the context of intake in future HM studies.

Comparative Analysis of Lipid Digestion Characteristics in Human, Bovine, and Caprine Milk Based on Simulated In Vitro Infant Gastrointestinal Digestion

Lipid digestion characteristics in human, bovine, and caprine milk were investigated using an infant in vitro digestion model. Our results suggested that particle size in bovine and caprine milk increased initially and then decreased over time, whereas the particle size in human milk continuously decreased. The lipolysis degree of human milk (86.8%) was higher than that in bovine (80.2%) and caprine (82.7%) milk (P < 0.05). Compared to human milk, bovine and caprine milk released higher unsaturated fatty acids and lower SFAs. In addition, 12 and 84 glyceride species were significantly different between bovine and human milk, during gastrointestinal digestion (P < 0.05). Another 13 and 92 glyceride species were found to be significantly different between caprine and human milk. A total of 30 and 31 lipids were screened as biomarkers to further clarify the differences related to lipid digestion properties of human, bovine, and caprine milk.

Simulated In Vitro Infant Gastrointestinal Digestion of Infant Formulas Containing Different Fat Sources and Human Milk: Differences in Lipid Profiling and Free Fatty Acid Release

Simulated in vitro infant gastrointestinal digestion of human milk and four infant formulas containing different fat sources was analyzed and compared in this study. Although there are disadvantages brought about by its larger droplet size than infant formulas, human milk exhibited a higher lipolysis level due to the presence of MFGM interfacial layers. Higher hydrolysis efficiency of infant formulas (IFB, IFC, and IFM) was due to the presence of MFGM/phospholipid-enriched materials. Human milk released higher free fatty acid levels, especially long-chain fatty acid, and less undigested TAG molecules at the end of digestion than infant formulas. Human milk had a higher proportion of MAG and DAG linked to long-chain fatty acid. Furthermore, several lipids were identified as potential biomarkers that could be used to further analyze differences in the biological properties of human, bovine, and caprine milk. This comprehensive analysis might be fruitful to formulate an infant formula closest to human milk.

Human Milk Microbiota and Oligosaccharides: A Glimpse into Benefits, Diversity, and Correlations

Human milk represents a cornerstone for growth and development of infants, with extensive array of benefits. In addition to exceptionally nutritive and bioactive components, human milk encompasses a complex community of signature bacteria that helps establish infant gut microbiota, contributes to maturation of infant immune system, and competitively interferes with pathogens. Among bioactive constituents of milk, human milk oligosaccharides (HMOs) are particularly significant. These are non-digestible carbohydrates forming the third largest solid component in human milk. Valuable effects of HMOs include shaping intestinal microbiota, imparting antimicrobial effects, developing intestinal barrier, and modulating immune response. Moreover, recent investigations suggest correlations between HMOs and milk microbiota, with complex links possibly existing with environmental factors, genetics, geographical location, and other factors. In this review, and from a physiological and health implications perspective, milk benefits for newborns and mothers are highlighted. From a microbiological perspective, a focused insight into milk microbiota, including origins, diversity, benefits, and effect of maternal diet is presented. From a metabolic perspective, biochemical, physiological, and genetic significance of HMOs, and their probable relations to milk microbiota, are addressed. Ongoing research into mechanistic processes through which the rich biological assets of milk promote development, shaping of microbiota, and immunity is tackled.

Regional similarities and differences in mature human milk fatty acids in Chinese population: A systematic review

Maternal factors such as the diet can impact human milk fatty acid profiles. We hypothesized that mature human milk fatty acid profiles differ among regions of China. To test our hypothesis, we conducted a systematic review to calculate regional average contents of fatty acids and the statistical significance of regional differences in fatty acids. We searched both Chinese and English literature databases and selected 21 articles, including 11 in Chinese and 10 in English. We categorized regions of China by 3 ways: 1) north vs. south; 2) inland vs. coastal; 3) socioeconomic development levels. The ratios of ΣSFAs:ΣMUFAs:ΣPUFAs were similar between regions and the average was 1:1:0.7. Contents of palmitic, oleic, and linoleic acids were also similar between regions and together they accounted for more than 70% of all fatty acids in mature human milk. Conversely, concentrations of ALA and DHA differed more than palmitic, oleic, and linoleic acids. We also found that it might be necessary to reduce maternal dietary contents of potentially harmful fatty acids such as erucic acid to minimize detrimental effects on infant health. To our knowledge, this study represents the first systematic review that quantitatively investigated the regional similarities and differences in mature human milk fatty acid contents and is therefore significant for academia and policy makers.

Association between duration of breastfeeding based on maternal reports and dorsal and ventral striatum and medial orbital gyrus volumes in early adolescence

Maternal breastfeeding has an impact on motor and emotional development in children of the next generation. Elucidating how breastfeeding during infancy affects brain regional structural development in early adolescence will be helpful for promoting healthy development. However, previous studies that have shown relationships between breastfeeding during infancy and cortical brain regions in adolescence are usually based on maternal retrospective recall of breastfeeding, and the accuracy of the data is unclear. In this study, we investigated the association between breastfeeding duration and brain regional volume in a population-neuroimaging study of early adolescents in Japan (N ​= ​207; 10.5-13.4 years) using voxel-based morphometry, which enabled us to analyze the whole brain. We evaluated breastfeeding duration as indexed by maternal and child health handbook records during infancy. The results showed a significant positive correlation between the duration of breastfeeding and gray matter volume in the dorsal and ventral striatum and the medial orbital gyrus. Post hoc exploratory analyses revealed that the duration of breastfeeding was significantly correlated with emotional behavior. Additionally, the volume in the medial orbital gyrus mediated an association between breastfeeding duration and emotional behavior. This is the first study to evaluate the effect of breastfeeding during infancy on regional brain volumes in early adolescence based on maternal and child health handbook records. Our findings shed light upon the importance of maternal breastfeeding for brain development related to emotional and motivational processing in early adolescence.

Untargeted lipidomics using liquid chromatography-ion mobility-mass spectrometry reveals novel triacylglycerides in human milk

Human milk provides the infant with the essential nutritive and non-nutritive factors required for health, growth and development. The human milk lipidome is complex, but comprises predominantly triacylglycerides. Historically, the fatty acid profile of the entire human milk lipidome has been investigated, and many relationships have been identified between infant health and fatty acids. Most of these fatty acids are, however, delivered to the infant as triacylglycerides. Using liquid chromatography-ion mobility-mass spectrometry, the objective of this study was to characterise the triacylglyceride profile of human milk and elucidate relationships between the triacylglyceride profile and infant outcomes in a cohort of 10 exclusively breastfeeding woman-infant dyads. 205 triacylglycerides were identified, including 98 previously not reported in human milk. The dose of specific triacylglycerides differed in relation to infant health, such as lauric acid containing TAGs, which were delivered in significantly higher dose to healthy infants compared to unwell infants.

Effects of energy and essential fatty acids content in breast milk on infant's head dimensions

OBJECTIVES

Essential fatty acids (EFA), including linoleic acid (LA) and alpha-linolenic acid (ALA), are indispensable for proper brain growth especially in the first months after birth when it develops most rapidly. Since fats, especially EFA, in breast milk are highly variable between mothers, we indirectly examined whether milk energy, LA and ALA content in breast milk affect volume and shape of the infant's head.

METHODS

The study encompassed 60 mothers and their healthy term-born infants between the third and sixth month of lactation. The percentage of macronutrients and dry matter in human milk samples was assessed using Fourier-transform infrared spectroscopy (FTIR), and LA and ALA concentrations in breast milk were determined using gas chromatography (GC). Infant head measurements were taken using standard anthropometric equipment and methods.

RESULTS

LA content in breast milk was found to be positively associated with head volume in boys. Furthermore, ALA content was positively associated with the head height-to-length ratio thus with more arched head in infants irrespective of sex. No relationship was found between milk energy content in mothers' milk and infant head dimensions.

CONCLUSIONS

This is the first study to demonstrate a relationship between EFA concentration in human milk and infant head dimensions. Given that LA and ALA in human milk are variable in women and due to the extremely rapid growth of nerve tissue in the first months of life, adequate supply of EFA in breast milk should attract the attention of public health sciences.

Human milk fatty acid composition is associated with dietary, genetic, sociodemographic, and environmental factors in the CHILD Cohort Study

BACKGROUND

Fatty acids are a vital component of human milk. They influence infant neurodevelopment and immune function, and they provide ∼50% of milk's energy content.

OBJECTIVES

The objectives of this study were to characterize the composition of human milk fatty acids in a large Canadian birth cohort and identify factors influencing their variability.

METHODS

In a subset of the CHILD cohort (n = 1094), we analyzed milk fatty acids at 3-4 mo postpartum using GLC. Individual and total SFAs, MUFAs, and n-3 and n-6 PUFAs were analyzed using SD scores and principal component analysis (PCA). Maternal diet, sociodemographic, health, and environmental factors were self-reported. Single-nucleotide polymorphisms were assessed in the fatty acid desaturase 1 (FADS1-rs174556) and 2 (FADS2-rs174575) genes.

RESULTS

Fatty acid profiles were variable, with individual fatty acid proportions varying from 2- to >30-fold between women. Using PCA, we identified 4 milk fatty acid patterns: "MUFA and low SFA," "high n-6 PUFA," "high n-3 PUFA," and "high medium-chain fatty acids." In multivariable-adjusted analyses, fish oil supplementation and fatty cold water fish intake were positively associated with DHA and the "high n-3 PUFA" pattern. Mothers carrying the minor allele of FADS1-rs174556 had lower proportions of arachidonic acid (ARA; 20:4n-6). Independent of selected dietary variables and genetic variants, Asian ethnicity was associated with higher linoleic acid (18:2n-6) and total n-3 PUFAs. Ethnic differences in ARA were explained by FADS1 genotype. Maternal obesity was independently associated with higher total SFAs, the "high medium-chain fatty acid" pattern, and lower total MUFAs. Lactation stage, season, study site, and maternal education were also independently associated with some milk fatty acids. No associations were observed for maternal age, parity, delivery mode, or infant sex.

CONCLUSIONS

This study provides unique insights about the "normal" variation in the composition of human milk fatty acids and the contributing dietary, genetic, sociodemographic, health, and environmental factors. Further research is required to assess implications for infant health.

Association of breast milk gamma-linolenic acid with infant anthropometric outcomes in urban, low-income Bangladeshi families: a prospective, birth cohort study

Background/Objectives

Infant linear-growth faltering remains a major public health issue in low- and middle-income countries and suboptimal breast milk composition may be a local, population-specific risk factor. The relationship between early post-natal breast milk fatty acid (FA) composition and infant growth at 1 and 2 years of age was investigated prospectively in 563 families in Dhaka, Bangladesh.

Subjects/Methods

A maternal breast milk sample drawn before infant age 6 weeks was analyzed for percentage composition of 26 FAs, and infant length for age Z score (LAZ) was measured longitudinally to infant age 2 years. Individual FAs were tested as predictors of the infant growth outcomes.

Results

Of 26 tested FAs, %gamma-linolenic acid (%GLA) was mostly significantly associated with increase in LAZ from 6 to 52 weeks (ΔLAZ(52−6w)), and also to 104 weeks. The association was consistent over all breast milk stages with estimated effect size of +0.05 ΔLAZ(52−6w) per 20% change in %GLA (p value = 3 × 10⁻⁶), and stronger for ΔLAZ(104−6w) at +0.06 (p value = 8 × 10⁻⁷), explaining 1% of the outcome variance. Infant serum zinc measurements at 6 and 18 weeks of age were included in adjusted analyses, suggesting at least partial independence of infant zinc levels. The association was strongest in 417/563 (74.1%) families with %GLA <0.2%. Breast milk arachidonic acid fraction was within normal range with weaker evidence of association in early breast milk stages.

Conclusions

This study found that %GLA in breast milk was independently associated with infant linear growth, albeit with small effect size, in a predominantly slum-dwelling, low-income, Bangladeshi cohort.

Quantification of Human Milk Phospholipids: the Effect of Gestational and Lactational Age on Phospholipid Composition

Human milk (HM) provides infants with macro- and micronutrients needed for growth and development. Milk phospholipids are important sources of bioactive components, such as long-chain polyunsaturated fatty acids (LC-PUFA) and choline, crucial for neural and visual development. Milk from mothers who have delivered prematurely (<37 weeks) might not meet the nutritional requirements for optimal development and growth. Using liquid chromatography tandem-mass spectrometry, 31 phospholipid (PL) species were quantified for colostrum (<5 days postpartum), transitional (≥5 days and ≤2 weeks) and mature milk (>2 weeks and ≤15 weeks) samples from mothers who had delivered preterm (n = 57) and term infants (n = 22), respectively. Both gestational age and age postpartum affected the PL composition of HM. Significantly higher concentrations (p < 0.05) of phosphatidylcholine (PC), sphingomyelin (SM) and total PL were found in preterm milk throughout lactation, as well as significantly higher concentrations (p < 0.002) of several phosphatidylethanolamine (PE), PC and SM species. Multivariate analysis revealed that PLs containing LC-PUFA contributed highly to the differences in the PL composition of preterm and term colostrum. Differences related to gestation decreased as the milk matured. Thus, gestational age may impact the PL content of colostrum, however this effect of gestation might subside in mature milk.

Temporal Progression of Fatty Acids in Preterm and Term Human Milk of Mothers from Switzerland

We longitudinally compared fatty acids (FA) from human milk (HM) of mothers delivering term and preterm infants. HM was collected for 4 months postpartum at 12 time points for preterm and for 2 months postpartum at 8 time points for term group. Samples were collected from the first feed of the morning, and single breast was fully expressed. FA were analyzed by gas chromatography coupled with flame ionization detector. Oleic, palmitic and linoleic acids were the most abundant FA across lactation and in both groups. Preterm colostrum contained significantly (p < 0.05) higher 8:0, 10:0, 12:0, sum medium chain fatty acids (MCFA), 18:3 n-3 FA compared to term counterparts. Preterm mature milk contained significantly higher 12:0, 14:0, 18:2 n-6, sum saturated fatty acids (SFA), and sum MCFA. We did not observe any significant differences between the preterm and term groups for docosahexaenoic acid, arachidonic acid and eicosapentaenoic acid at any stage of lactation. Overall, preterm milk was higher for SFA with a major contribution from MCFA and higher in 18:2 n-6. These observational differences needs to be studied further for their implications on preterm developmental outcomes and on fortification strategies of either mothers’ own milk or donor human milk.

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.

MiR-183 regulates milk fat metabolism via MST1 in goat mammary epithelial cells

The nutritional value of goat milk largely depends on its fatty acid content and composition. MicroRNAs (miRNAs) are a class of RNA molecules 18-25nt in length that regulate gene expression and play crucial roles in several biological processes, including fatty acid metabolism. In this study, we analyzed the correlation between differentially expressed miRNAs in goat mammary tissue and the fatty acid composition of goat milk by using Pearson correlations. Results revealed that levels of miR-183 were highly and positively correlated with the fatty acid content in the milk. In addition, we demonstrated that overexpression of miR-183 inhibits milk fat metabolism and inhibition of miR-183 promotes milk fat metabolism. Using Western blot, we demonstrate that MST1, one of the major elements of the Hippo signaling pathway, is a target of miR-183. Immunofluorescence assays revealed that miR-183 targets MST1 in the cytoplasm. In summary, data indicate that miR-183 inhibits the metabolism of milk fat by targeting the MST1 gene in the cytoplasm in goat mammary epithelial cells.

Supplementing dams with both arachidonic and docosahexaenoic acid has beneficial effects on growth and immune development

Omega-3 long-chain polyunsaturated fatty acids (LCPUFAS) modulate immune cells in vitro and in vivo. This study investigated the effects of enriching the maternal diet with the n-6 and n-3 LCPUFAs, arachidonic (20:4n-6, 0.6%wt ARA) and docosahexaenoic acid (22:6n-3, 0.32%wt DHA), or 1:1 and 2:1 ratios (ARA: DHA) on total lipids in milk, total lipids, and immunophenotypes in plasma, lymph nodes, and spleen from isolated immune cells from 28d old pups. From day 15 of gestation to day 3 pp, Sprague-Dawley dams were fed a commercial chow. On day 3 pp litters were culled and pups (4 males and 2 females) randomly cross-fostered to dams who were randomized to one of the 5 experimental diets resulting in 20 male and 10 female pups/diet group. Dams fed ARA or ARA: DHA had 28-36% more 20:4n-6 in milk and feeding DHA or ARA: DHA doubled 22:6n-3 in milk lipids (P<0.05). Feeding 1:1 or 2:1 ARA: DHA resulted in greater pup weight at weaning (P<0.05). Compared to the control pups, ARA + DHA fed pups had a lower proportion of splenic CD45RA+ lymphocytes. In summary, postpartum supplementation with a combination of ARA + DHA, compared to ARA or DHA alone, resulted in a higher content of ARA and DHA in dam's milk and tissues and had positive effects on growth, accompanied by evidence of progression toward a mature immune phenotype, and suggests a need for ARA when DHA is supplemented in the early diet. Additional investigations are needed of ARA immunomodulation to better understand and estimate nutritional requirements for LCPUFAs during early development.

Total Long-Chain n-3 Fatty Acid Intake and Food Sources in the United States Compared to Recommended Intakes: NHANES 2003-2008

The American Heart Association recommends consuming fish (particularly oily fish) at least two times per week, which would provide ≈ 0.5 g/day of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for cardiovascular disease risk reduction. Previous analyses indicate that this recommendation is not being met; however, few studies have assessed different ethnicities, subpopulations requiring additional n-3 fatty acid intake (i.e., children and pregnant and/or lactating women), or deciles of intake. Data from the National Health and Nutrition Examination Survey 2003-2008 was used to assess n-3 fatty acid intake from foods and supplements in the US population, according to age, sex, and ethnicity. A unique "EPA equivalents" factor, which accounts for potential conversion of shorter-chain n-3 fatty acids, was used to calculate total long-chain n-3 fatty acid intake. Data are reported for 24,621 individuals. More than 90% consumed less than the recommended 0.5 g/day from food sources (median = 0.11 g/day; mean = 0.17 g/day). Among the top 15% of n-3 fatty acid consumers, fish was the largest dietary contributor (71.2%). Intake was highest in men aged 20 years or more, and lowest in children and women who are or may become pregnant and/or are lactating. Among ethnicities, intake was lowest in Mexican-Americans. Only 6.2% of the total population reported n-3 fatty acid supplement use, and this did not alter median daily intake. Additional strategies are needed to increase awareness of health benefits (particularly among Mexican-Americans and women of childbearing age) and promote consumption of oily fish or alternative dietary sources to meet current recommendations.

"Omics" in Human Colostrum and Mature Milk: Looking to Old Data with New Eyes

Human Milk (HM) is the best source for newborn nutrition until at least six months; it exerts anti-inflammatory and anti-infective functions, promotes immune system formation and supports organ development. Breastfeeding could also protect from obesity, diabetes and cardiovascular disease. Furthermore, human colostrum (HC) presents a peculiar role in newborn support as a protective effect against allergic and chronic diseases, in addition to long-term metabolic benefits. In this review, we discuss the recent literature regarding "omics" technologies and growth factors (GF) in HC and the effects of pasteurization on its composition. Our aim was to provide new evidence in terms of transcriptomics, proteomics, metabolomics, and microbiomics, also in relation to maternal metabolic diseases and/or fetal anomalies and to underline the functions of GF. Since HC results are so precious, particularly for the vulnerable pre-terms category, we also discuss the importance of HM pasteurization to ensure donated HC even to neonates whose mothers are unable to provide. To the best of our knowledge, this is the first review analyzing in detail the molecular pattern, microbiota, bioactive factors, and dynamic profile of HC, finding clinical correlations of such mediators with their possible in vivo effects and with the consequent impact on neonatal outcomes.

Fatty acid composition and phospholipid types used in infant formulas modifies the establishment of human gut bacteria in germ-free mice

Human milk fat contains high concentrations of medium-chained fatty acids (MCFA) and triacylglycerols emulsified by a sphingomyelin-rich phospholipid membrane (milk phospholipids, MPL). Infant formula comprises mainly long-chained fatty acids (LCFA) emulsified with dairy proteins and soy lecithin (SL) lacking sphingomyelin. Sphingomyelin content and saturation level of phospholipids affect the gut lipase activity, which alters the concentrations of lipid hydrolysis products in ileum and colon, and hereby putatively affects the competitive advantage of specific gut bacteria. Thus, differences in phospholipid and FA composition may modulate the establishment of the gut microbiota. We investigated effects of fatty acid (FA) composition and emulsification (MPL vs SL) ingested during establishment of human gut microbiota in germ-free mice, and found that cecal microbiotas from mice given MCFA-rich emulsions were characterized by high relative abundances of Bacteroidaceae and Desulfovibrionaceae, while LCFA-rich emulsions caused higher abundances of Enterobacteriaceae, Erysipelotrichaceae, Coriobacteriaceae and Enterococcaceae. Consumption of SL-emulsified lipids skewed the community towards more Enterococcaceae and Enterobacteriaceae, while MPL increased Bacteroidaceae, Desulfovibrionaceae, Rikkenellaceae and Porphyromonadaceae. Intake of SL increased cecal concentrations of iso-valeric and iso-butyric acids. This suggests that fat-type and emulsifiers applied in infant formula may have distinct effects on the establishment of the gut microbiota in formula-fed infants.

Role of Phospholipid Flux during Milk Secretion in the Mammary Gland

Lipids are a complex group of chemical compounds that are a significant component of the human diet and are one of the main constituents of milk. In mammals, lipids are produced in the milk-secreting cells in the form of milk fat globules. The chemical properties of these compounds necessitate developing separate processes for effective management of non-polar substances in the polar environment of the cell, not only during their biosynthesis and accumulation in the cell interior and secretion of intracytoplasmic lipid droplets outside the cell, but also during digestion in the offspring. Phospholipids play an important role in these processes. Their characteristic properties make them indispensable for the secretion of milk fat as well as other milk components. This review investigates how these processes depend on the coordinated flux and availability of phospholipids and how the relationship between the surface area (phospholipids) and volume (neutral lipids) of the cytoplasmic lipid droplets must be in biosynthetic balance. The structure formed as a result (i.e. a milk fat globule) is therefore a result of specified structural limitations inside the cell, whose overcoming enables the coordinated secretion of milk components. This structure and its composition also reflects the nutritional demands of the developing infant organism as a result of evolutionary adaptation.

Classification of Human Milks Based on Their Trans 18:1 Fatty Acid Profile and Effect of Maternal Diet

BACKGROUND

The diet of breastfeeding women influences the trans fatty acid (TFA) composition of the milk excreted. However, the effects associated to TFA are isomer-dependent and diverse TFA profiles may have different nutritional implications.

OBJECTIVE

The aim of this research was to evaluate whether certain TFA patterns in human milk fat can be used as indicators of TFA intake from different sources.

METHODS

Milk fat from 60 women were examined and classified based on their TFA profile and conjugated linoleic acid (CLA) contents by principal component analysis (PCA).

RESULTS

The PCA of the data allowed the classification of the women into 3 groups depending on milk TFA content and profile. From the 60 subjects, 19 presented a TFA profile characteristic of ruminant products intake, 10 a typical TFA profile of industrial trans fats consumption and 31 a negligible trans content. Superimposed on this, 21 women presented high amounts of docosahexaenoic acid (22:6 n-3) which was related to fish intake.

CONCLUSIONS

The present research overcome problems associated to heterogeneous groups in nutritional experiments by a statistical classification of lactating subjects based on the TFA composition of their milk. This classification could be extrapolated to other nutritional studies dealing with TFA analysis and samples of different nature as biological samples or foodstuffs.

Factors affecting human colostrum fatty acid profile: A case study

The role of maternal colostrum to infant development has been extensively studied and presented. Among the main factors which contribute to breast milk composition are maternal diet, age and body mass index, parity, duration of pregnancy and stage of lactation. This study aims to investigate the potential impact of several factors including demographic (i.e. maternal age and nationality) on the colostrum fatty acid profile. Colostrum was collected the third day postpartum in a Greek maternity hospital. Certain lipid quality indices and fatty acid ratios were estimated and results were statistically processed. The main identified fatty acids were palmitic (C16:0), oleic (C18:1ω-9), and linoleic (C18:2ω-6) acids. Among fatty acids, saturated fatty acids predominated (47.61%), followed by monounsaturated fatty acids (39.26%), while polyunsaturated fatty acids had the lowest proportion (13.13%). Values of lipid quality indices were within the reported in the literature ranges. Maternal body mass index, nationality, age, mode of delivery, gender and fetal weight percentile were studied in respect to their potential influence on the fatty acid profile of colostrum fat. Results suggest that colostrum fatty acid profile was mainly dependent on maternal nationality and age rather than mode of delivery and maternal BMI. Regarding the effect of maternal nationality, significant differences were found for saturated and monounsaturated fatty acids. Of the most interesting findings is that colostrum fat from older (≥35 years) mothers had less saturated fat and more appropriate LQIs values. Finally, a reversed correlation was observed between the customized centile of the infants and the colostrum fat content.

Genes regulating lipid and protein metabolism are highly expressed in mammary gland of lactating dairy goats

Dairy goats serve as an important source of milk and also fulfill agricultural and economic roles in developing countries. Understanding the genetic background of goat mammary gland is important for research on the regulatory mechanisms controlling tissue function and the synthesis of milk components. We collected tissue at four different stages of goat mammary gland development and generated approximately 25 GB of data from Illumina de novo RNA sequencing. The combined reads were assembled into 51,361 unigenes, and approximately 60.07 % of the unigenes had homology to other proteins in the NCBI non-redundant protein database (NR). Functional classification through eukaryotic Ortholog Groups of Protein (KOG), gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the unigenes from goat mammary glands are involved in a wide range of biological processes and metabolic pathways, including lipid metabolism and lactose metabolism. The results of qPCR revealed that genes encoding FABP3, FASN, SCD, PLIN2, whey proteins (LALBA and BLG), and caseins (CSN1S1, CSN1S2, CSN2 and CSN3) at 100 and 310 days postpartum increased significantly compared with the non-lactating period. In addition to their role in lipid and protein synthesis, the higher expression at 310 days postpartum could contribute to mammary cell turnover during pregnancy. In conclusion, this is the first study to characterize the complete transcriptome of goat mammary glands and constitutes a comprehensive genomic resource available for further studies of ruminant lactation.

Exclusive breastfeeding and developmental and behavioral status in early childhood

Breastfeeding during infancy may have beneficial effects on various developmental outcomes in childhood. In this study, exclusively breastfed infants were randomly assigned to receive complementary foods from the age of 4 months in addition to breast milk (CF, n = 60), or to exclusively breastfeed to 6 months (EBF, n = 59). At 18 months and again at 30–35 months of age, the children were evaluated with the Parent’s Evaluation of Developmental Status questionnaire (PEDS) and the Brigance Screens-II. The parents completed the PEDS questionnaire at both time intervals and the children underwent the Brigance Screens-II at 30–35 months. At 30–35 months, no significant differences were seen in developmental scores from the Brigance screening test (p = 0.82). However, at 30–35 months a smaller percentage of parents in group CF (2%) had concerns about their children’s gross motor development compared to those in group EBF (19%; p = 0.01), which remained significant when adjusted for differences in pre-randomization characteristics (p = 0.03). No sustained effect of a longer duration of exclusive breastfeeding was seen on selected measures of developmental and behavioral status at 18 months, although at 30–35 months, a smaller percentage of parents of children introduced to complementary foods at four months of age expressed concerns about their gross motor development.

The lipid fraction of human milk initiates adipocyte differentiation in 3T3-L1 cells

BACKGROUND

The prevalence of childhood obesity has increased worldwide over the past decade. Despite evidence that human milk lowers the risk of childhood obesity, the mechanism is not fully understood.

AIMS

We investigated the direct effect of human milk on differentiation of 3T3-L1 preadipocytes.

STUDY DESIGN AND SUBJECTS

3T3-L1 preadipocytes were treated with donated human milk only or the combination of the standard hormone mixture; insulin, dexamethasone (DEX), and 3-isobututyl-1-methylxanthine (IBMX). Furthermore, the induction of preadipocyte differentiation by extracted lipids from human milk was tested in comparison to the cells treated with lipid extracts from infant formula. Adipocyte differentiation, specific genes as well as formation of lipid droplets were examined.

RESULTS

We clearly show that lipids present in human milk initiate 3T3-L1 preadipocyte differentiation. In contrast, this effect was not observed in response to lipids present in infant formula. The initiation of preadipocyte differentiation by human milk was enhanced by adding the adipogenic hormone, DEX or insulin. The expression of late adipocyte markers in Day 7 adipocytes that have been induced into differentiation with human milk lipid extracts was comparable to those in control cells initiated by a standard adipogenic hormone cocktail.

CONCLUSIONS

These results demonstrate that human milk contains bioactive lipids that can initiate preadipocyte differentiation in the absence of the standard adipogenic compounds via a unique pathway.

Nutrition, insulin-like growth factor-1 and retinopathy of prematurity

Retinopathy of prematurity is a potentially blinding disease starting with impaired retinal vessel growth in the neonatal period. Weeks to months later, peripheral retinal hypoxia induces pathologic neovascularization that may lead to retinal detachment and blindness. Current treatment strategies target late stage disease and it would be advantageous if retinopathy of prematurity could be prevented. Poor general growth after very preterm birth is a universal problem associated with increased risk of retinopathy. Loss of the maternal-fetal interaction results not only in loss of nutrients but also of other factors provided in utero. The importance of nutrition and factors such as insulin-like growth factor-1 and ω-3 long chain fatty acids for proper retinal vascularization has been defined in animal studies. Increasing evidence of the applicability of these findings to human infants is accumulating. This review focuses on factors essential for neonatal growth and possible strategies to improve growth and prevent retinopathy.

Model for human milk fat substitute evaluation based on triacylglycerol composition profile

Being the dominant components in human milk fat (HMF), triacylglycerol (TAG) composition might be the best approximation index to represent the composing characteristics of HMF. In this study, TAG composition of HMF from different lactation stages was analyzed by RP-HPLC-APCI-MS, and the establishment of a model for the precise evaluation of human milk fat substitutes (HMFSs) based on TAG composition was indirectly realized by employment of fatty acid composition and distribution and polyunsaturated fatty acid (PUFA) and TAG compositions. The model was verified by the selected fats and oils with specific chemical compositions, and the results revealed the degrees of similarity of these fats and oils in different evaluation aspects reflected their differences in corresponding chemical composition with HMF. The newly established evaluation model with TAG composition as a comparison base could provide a more accurate method to evaluate HMFSs and might have some inspirations for HMFS production in the future.

Metabolomics of dietary fatty acid restriction in patients with phenylketonuria

Background

Patients with phenylketonuria (PKU) have to follow a lifelong phenylalanine restricted diet. This type of diet markedly reduces the intake of saturated and unsaturated fatty acids especially long chain polyunsaturated fatty acids (LC-PUFA). Long-chain saturated fatty acids are substrates of mitochondrial fatty acid oxidation for acetyl-CoA production. LC-PUFA are discussed to affect inflammatory and haemostaseological processes in health and disease. The influence of the long term PKU diet on fatty acid metabolism with a special focus on platelet eicosanoid metabolism has been investigated in the study presented here.

Methodology/Principal Findings

12 children with PKU under good metabolic control and 8 healthy controls were included. Activated fatty acids (acylcarnitines C6–C18) in dried blood and the cholesterol metabolism in serum were analyzed by liquid chromatographic tandem mass spectrometry (LC-MS/MS). Fatty acid composition of plasma glycerophospholipids was determined by gas chromatography. LC-PUFA metabolites were analyzed in supernatants by LC-MS/MS before and after platelet activation and aggregation using a standardized protocol. Patients with PKU had significantly lower free carnitine and lower activated fatty acids in dried blood compared to controls. Phytosterols as marker of cholesterol (re-) absorption were not influenced by the dietary fatty acid restriction. Fatty acid composition in glycerophospholipids was comparable to that of healthy controls. However, patients with PKU showed significantly increased concentrations of y-linolenic acid (C18:3n-6) a precursor of arachidonic acid. In the PKU patients significantly higher platelet counts were observed. After activation with collagen platelet aggregation and thromboxane B₂ and thromboxane B₃ release did not differ from that of healthy controls.

Conclusion/Significance

Long-term dietary fatty acid restriction influenced the intermediates of mitochondrial beta-oxidation. No functional influence on unsaturated fatty acid metabolism and platelet aggregation in patients with PKU was detected.

Fatty acids as biocompounds: their role in human metabolism, health and disease: a review. part 2: fatty acid physiological roles and applications in human health and disease

BACKGROUND

This is the second of two review parts aiming at describing the major physiological roles of fatty acids, as well as their applications in specific conditions related to human health.

RESULTS

The review included the current literature published in Pubmed up to March 2011. In humans, fatty acids are a principle energy substrate and structural components of cell membranes (phospholipids) and second messengers. Fatty acids are also ligands of nuclear receptors affecting gene expression. Longer-chain (LC) polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid are precursors of lipid mediators such as eicosanoids (prostaglandins, leukotrienes, thromboxanes), resolvins and neuroprotectins. Lipid mediators produced by EPA and DHA (LC n-3 PUFA; mainly found in oily fish) are considered as inflammation-resolving, and thus, fish oil has been characterised as antiinflammatory. Recommendations for EPA plus DHA intake from oily fish vary between 250-450 mg/day. Dietary reference values for fat vary between nutrition bodies, but mainly agree on a low total and saturated fat intake. The existing literature supports the protective effects of LC n-3 PUFA (as opposed to n-6 PUFA and saturated fat) in maternal and offspring health, cardiovascular health, insulin sensitivity, the metabolic syndrome, cancer, critically ill patients, and immune system disorders.

CONCLUSION

Fatty acids are involved in multiple pathways and play a major role in health. Further investigation and a nutrigenomics approach to the effects of these biocompounds on health and disease development are imperative and highlight the importance of environmental modifications on disease outcome.

Comparative evaluation of essential fatty acid composition of mothers' milk of some urban and suburban regions of West Bengal, India

This study investigated the fatty acid composition of lipid present in breast milk of mothers residing in urban and suburban regions of West Bengal with special emphasis on n-6 and n-3 polyunsaturated fatty acids, which played a crucial role in the growth and development of neonates. Milk samples collected from 135 mothers of middle income group (average monthly income around 'Rs 10,000/-') were analysed by gas liquid chromatography after extraction and transmethylation to determine fatty acid composition. Information about the dietary intake of individual mothers was obtained through food frequency questionnaire. The fractions of n-6 and n-3 polyunsaturated fatty acids available in milk of urban mothers were 13.59 ± 0.94 and 3.65 ± 0.49, respectively, and in suburban mothers 12.74 ± 0.89 and 4.36 ± 0.39, respectively. The green leafy vegetables, fishes and vegetable oils were the major sources of essential fatty acids in the diet of the experimental groups of Bengali mothers. This study revealed a relationship between the alimentary habits of mothers and the concentration of essential fatty acids in breast milk of Bengali mothers.

Differences in preterm and term milk fatty acid compositions may be caused by the different hormonal milieu of early parturition

INTRODUCTION

The hormonal milieus of pregnancy and lactation are driving forces of nutrient fluxes supporting infant growth and development. The decrease of insulin sensitivity with compensatory hyperinsulinemia with advancing gestation, causes adipose tissue lipolysis and hepatic de novo lipogenesis (DNL).

SUBJECTS AND METHODS

We compared fatty acid (FA) contents and FA-indices for enzyme activities between preterm (28-36 weeks) and term (37-42) milks, and between colostrum (2-5 days), transitional (6-15) and mature (16-56) milks. We interpreted FA differences between preterm and term milks, and their changes with lactation, in terms of the well known decrease of insulin sensitivity during gestation and its subsequent postpartum restoration, respectively.

RESULTS

Compared with term colostrum, preterm colostrum contained higher indices of DNL in the breast (DNL-breast) and medium chain saturated-FA (MCSAFA), and lower DNL-liver and monounsaturated-FA (MUFA). Preterm milk also had higher docosahexaenoic acid (DHA) in colostrum and transitional milk and higher arachidonic acid (AA) in mature milk. Most preterm-term differences vanished with advancing lactation. In both preterm and term milks, DNL-breast and MCSAFA increased with advancing lactation, while DNL-liver, MUFA, long chain SAFA and AA decreased. DHA decreased in term milk. MUFA was inversely related to MCSAFA in all samples, correlated inversely with PUFA in colostrum and transitional milks, but positively in mature milk. MCSAFA correlated inversely with PUFA in mature milk.

CONCLUSION

Higher maternal insulin sensitivity at preterm birth may be the cause of lower MUFA (a proxy for DNL-liver) and higher MCSAFA (a proxy for DNL-breast) in preterm colostrum, compared with term colostrum. Restoring insulin sensitivity after delivery may be an important driving force for milk FA-changes in early lactation.

Determinants of adipophilin function in milk lipid formation and secretion

In many species the lactating mammary gland is one of the most lipogenic organs of the body. The majority of the lipid produced during lactation is secreted into milk by a novel process of membrane envelopment of cytoplasmic lipid droplets (CLDs). Adipophilin (ADRP/ADPH/PLIN2), a member of the perilipin (PAT) family of lipid droplet proteins, is hypothesized to play a pivotal role in both formation and secretion of milk lipids. Production of milk lipids is the only known example of CLD secretion, and the only process in which PAT family members undergo secretion. This review discusses emerging data on the structural and functional properties of adipophilin that determine its physiological actions and mediate its effects on milk lipid formation and secretion.

Postpartum changes in maternal and infant erythrocyte fatty acids are likely to be driven by restoring insulin sensitivity and DHA status

INTRODUCTION

Perinatal changes in maternal glucose and lipid fluxes and de novo lipogenesis (DNL) are driven by hormones and nutrients. Docosahexaenoic acid (DHA) reduces, whereas insulin augments, nuclear abundance of sterol-regulatory-element-binding-protein-1 (SREBP-1), which promotes DNL, stearoyl-CoA-desaturase (SCD, also Δ9-desaturase), fatty acid-(FA)-elongation (Elovl) and FA-desaturation (FADS). Decreasing maternal insulin sensitivity with advancing gestation and compensatory hyperinsulinemia cause augmented postprandial glucose levels, adipose tissue lipolysis and hepatic glucose- and VLDL-production. Hepatic VLDL is composed of dietary, body store and DNL derived FA. Decreasing insulin sensitivity increases the contribution of FA from hepatic-DNL in VLDL-triacylglycerols, and consequently saturated-FA and monounsaturated-FA (MUFA) in maternal serum lipids increase during pregnancy. Although other authors described changes in maternal serum and RBC essential-FA (EFA) after delivery, none went into detail about the changes in non-EFA and the mechanisms behind -and/or functions of- the observed changes.

HYPOTHESIS

Postpartum FA-changes result from changing enzymatic activities that are influenced by the changing hormonal milieu after delivery and DHA-status.

EMPIRICAL DATA

We studied FA-profiles and FA-ratios (as indices for enzymatic activities) of maternal and infant RBC at delivery and after 3 months exclusive breastfeeding in three populations with increasing freshwater-fish intakes. DNL-, SCD- and FADS2-activities decreased after delivery. Elongation-6 (Elovl-6)- and FADS1-activities increased. The most pronounced postpartum changes for mothers were increases in 18:0, linoleic (LA), arachidonic acid (AA) and decreases in 16:0, 18:1ω9 and DHA; and for infants increases in 18:1ω9, 22:5ω3, LA and decreases in 16:0 and AA. Changes were in line with the literature.

DISCUSSION

Postpartum increases in 18:0, and decreases in 16:0 and 18:1ω9, might derive from reduced insulin-promoted DNL-activity, with more reduced SCD- than Elovl-activity that leaves more 16:0 to be converted to 18:0 (Elovl-activity) than to MUFA (SCD-activity). Postpartum changes in ΣDNL, saturated-FA and MUFA related negatively to RBC-DHA. This concurs with suppression of both SCD- and Elovl-6 activities by DHA, through its influence on SREBP. Infant MUFA and LA increased at expense of their mothers. Sustained transport might be important for myelination (MUFA) and skin barrier development (LA). Maternal postpartum decreases in FADS2-, and apparent increases in FADS1-activity, together with increases in LA, AA, and 22:5ω3, but decrease in DHA, confirm that FADS2 is rate limiting in EFA-desaturation. Maternal LA and AA increases might be the result of rerouting from transplacental transfer to the incorporation into milk lipids and discontinued placental AA-utilization.

IMPLICATIONS

Perinatal changes in maternal and infant FA status may be strongly driven by changing insulin sensitivity and DHA status.

Long chain polyunsaturated fatty acids in mothers of preterm babies

AIMS

to examine the levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) in both plasma and erythrocytes of maternal and cord blood as well as in breast milk of mothers of preterm babies.

METHODS

a total of 63 mothers of preterm babies were recruited from the Bharati Medical Hospital, Pune, India.

RESULTS

plasma and erythrocyte DHA and AA levels were higher (P<0.001) in cord blood than in maternal blood. Maternal plasma DHA and AA were positively (P<0.01) associated with their respective maternal erythrocyte levels. There was a positive association (P<0.01) between maternal DHA (both plasma and erythrocyte) and cord DHA. Maternal plasma omega 3 and 6 fatty acids were positively (P<0.01) associated with their respective milk fatty acids.

CONCLUSIONS

higher DHA and AA levels in cord blood compared to the mothers suggests a special mechanism to meet the increased demand of the fetus. Higher levels of milk DHA reflect the increased postnatal requirement of preterm babies suggesting a vital role for maternal milk. Lower maternal erythrocyte DHA concentrations in mothers delivering preterm as compared to term suggest that increased oxidative stress may be responsible for reduced DHA levels. This may alter the uterotonic factors like prostaglandins leading to premature triggering of labor.