Term Breast Milk Research Articles

Banked preterm versus banked term human milk to promote growth and development in very low birth weight infants.

Human milk banking has been available in many countries for the last three decades. The milk provided from milk banking is predominantly term breast milk, but some milk banks provide preterm breast milk. There are a number of differences between donor term and donor preterm human milk. To determine the effect of banked donor preterm milk compared with banked donor term milk regarding growth and developmental outcomes in very low birth weight infants (infants weighing less than 1500 grams). We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 7), MEDLINE via PubMed (1966 to 23 October 2018), Embase (1980 to 23 October 2018), and CINAHL (1982 to 23 October 2018). We also searched clinical trial databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. Randomised and quasi-randomised trials comparing banked donor preterm milk with banked donor term milk regarding growth and developmental outcomes in very low birth weight infants DATA COLLECTION AND ANALYSIS: We planned to perform assessment of methodology regarding blinding of randomisation, intervention and outcome measurements as well as completeness of follow-up. We planned to evaluate treatment effect using a fixed-effect model using relative risk (RR), relative risk reduction, risk difference (RD) and number needed to treat for an additional beneficial outcome (NNTB) or the number needed to treat for an additional harmful outcome (NNTH) for categorical data; and using mean, standard deviation and weighted mean difference (WMD) for continuous data. We planned to use the GRADE approach to assess the quality of evidence. No studies met the inclusion criteria. We found no evidence to support or refute the effect of banked donor preterm milk compared to banked term milk regarding growth and developmental outcomes in very low birth weight infants.

Do the adiponectin and leptin levels in preterm and term breast milk samples relate to infants' short-term growth?

Adiponectin and leptin are involved in appetite control and body weight regulation. We aimed to evaluate the relationship between breast milk adipokine levels and short-term growth of preterm and term infants. Thirty-one preterm (median=35.3 weeks) and 34 term (median=38.7 weeks) infants were enrolled. Enzyme-linked immunosorbent assay was used to detect adipokines in mature milk. Infant growth was followed during the first 3 months. Although weight gain in the first month was insufficient, positive linear growth was observed in the following months for preterm infants, while term infants had positive steady linear growth. The median level of adipokines was found to be higher in preterm infants (P>0.05). Adiponectin showed significant negative correlations with some anthropometric measurements of term infants. However, in preterm infants, adiponectin was negatively correlated with length increment and positively correlated with body mass index (BMI) increment in the second-third month. In addition, leptin was negatively associated with the head circumference at birth in preterm infants and the triceps skinfold thickness increment in the first-second month term infants (P<0.05). In linear regression models, while gestational age, adiponectin and leptin were not related, maternal age and pre-pregnancy BMI had effects on body weight increment in 0-1 months (P<0.05). In conclusion, adiponectin may affect short-term growth, while leptin has no important effect. It would be beneficial to carry out longitudinal studies to evaluate the effects of these adipokines on the growth of infants.

An infant formula containing dairy lipids increased red blood cell membrane Omega 3 fatty acids in 4\xa0month-old healthy newborns: a randomized controlled trial

BackgroundWhen breastfeeding is not possible, infants are fed formulas (IF) in which lipids are usually of plant origin. However, the use of dairy fat in combination with plant oils enables a lipid profile closer to breast milk in terms of fatty acid (FA) composition, triglyceride structure, polar lipids and cholesterol contents. The objective of this study was to determine the effect of an IF containing a mix of dairy fat and plant oils on Omega-3 FA content in red blood cells (RBC).MethodsThis study was a monocentric, double-blind, controlled, randomized trial. Healthy term infants were fed formulas containing a mix of dairy fat and plant oils (D), plant oils (P) or plant oils supplemented with ARA and DHA (PDHA). Breastfed infants were enrolled as a reference group (BF). FA in RBC phosphatidylethanolamine was evaluated after 4 months and FA in whole blood were evaluated at enrollment and after 4 months by gas chromatography. Differences between groups were assessed using an analysis of covariance with sex and gestational age as covariates.ResultsSeventy IF-fed and nineteen BF infants completed the protocol. At 4 months, RBC total Omega-3 FA levels in infants fed formula D were significantly higher than in group P and similar to those in groups PDHA and BF. RBC DHA levels in group D were also higher than in group P but lower than in groups PDHA and BF. RBC n-3 DPA levels in group D were higher than in groups P, PDHA and BF. A decrease in proportions of Omega-3 FA in whole blood was observed in all groups.ConclusionsA formula containing a mix of dairy lipids and plant oils increased the endogenous conversion of Omega-3 long-chain FA from precursor, leading to higher total Omega-3, DPA and DHA status in RBC than a plant oil-based formula. Modifying lipid quality in IF by adding dairy lipids should be considered as an interesting method to improve Omega-3 FA status.Trial registrationIdentifier NCT01611649, retrospectively registered on May 25, 2012.

No effect of adding dairy lipids or long chain polyunsaturated fatty acids on formula tolerance and growth in full term infants: a randomized controlled trial

BackgroundWhen breastfeeding is not possible, infants are fed formulas in which lipids are usually of plant origin. However, the use of dairy fat in combination with plant oils enables a lipid profile in formula closer to breast milk in terms of fatty acid composition, triglyceride structure and cholesterol content. The objectives of this study were to investigate the impact on growth and gastrointestinal tolerance of a formula containing a mix of dairy lipids and plant oils in healthy infants.MethodsThis study was a monocentric, double-blind, controlled, randomized trial. Healthy term infants aged less than 3 weeks whose mothers did not breastfeed were randomly allocated to formula containing either: a mix of plant oils and dairy fat (D), only plant oils (P) or plant oils supplemented with long-chain polyunsaturated fatty acids (PDHA). Breastfed infants were included in a reference group (BF). Anthropometric parameters and body composition were measured after 2 and 4 months. Gastrointestinal tolerance was evaluated during 2 day-periods after 1 and 3 months thanks to descriptive parameters reported by parents. Nonrandomized BF infants were not included in the statistical analysis.ResultsEighty eight formula-fed and 29 BF infants were enrolled. Gains of weight, recumbent length, cranial circumference and fat mass were similar between the 3 formula-fed groups at 2 and 4 months and close to those of BF. Z-scores for weight, recumbent length and cranial circumference in all groups were within normal ranges for growth standards. No significant differences were noted among the 3 formula groups in gastrointestinal parameters (stool frequency/consistency/color), occurrence of gastrointestinal symptoms (abdominal pain, flatulence, regurgitation) or infant’s behavior.ConclusionsA formula containing a mix of dairy lipids and plant oils enables a normal growth in healthy newborns. This formula is well tolerated and does not lead to abnormal gastrointestinal symptoms. Consequently, reintroduction of dairy lipids could represent an interesting strategy to improve lipid quality in infant formulas.Trial registrationClinicalTrials.gov Identifier NCT01611649, retrospectively registered on May 25, 2012.

The impact of lactation and gestational age on the composition of branched-chain fatty acids in human breast milk.

Breast milk consumption reduces the incidence of necrotizing enterocolitis (NEC) in preterm infants compared to formula. Branched-chain fatty acids (BCFAs) are present in breast milk but not in most formulas intended for preterm infants. We aimed to determine the composition of BCFAs in the breast milk of mothers with preterm infants, and to understand the impact of gestational age at birth and stage of lactation on BCFA content. The main BCFAs in preterm breast milk were iso-14:0, iso-15:0, anteiso-15:0, iso-16:0, iso-17:0, and anteiso-17:0. Breast milk BCFAs as a percent of total fatty acids (g per 100 g, %) were significantly different across lactation stages, with the highest concentration in colostrum, followed by transitional and mature breast milk (median: 0.41, 0.31, and 0.28%, respectively, p < 0.05). Lower BCFAs in preterm breast milk compared to term breast milk may have been related to maternal intake, or the ability of the mammary gland to extract BCFA from plasma, or differences in mammary gland BCFA synthesis. BCFAs were mainly in the sn-2 position (52-65%), similar to palmitic acid. Overall, preterm and term breast milk BCFAs were similar and showed specific concentration patterns, resembling 16:0 with respect to sn-2 positional distribution. BCFAs were reduced with lactation stage, similar to highly unsaturated fatty acids.

Tryptophan metabolic profile in term and preterm breast milk: implications for health

Breast milk is the only source of the essential amino acid tryptophan (TRP) in breast-fed infants. Low levels of TRP could have implications for infant neurodevelopment. The objectives of the present study were to compare the relationship of TRP and its neuroactive pathway metabolites kynurenine (Kyn) and kynurenic acid (KynA) in preterm and term expressed breast milk (EBM) in the first 14 d following birth, and the relationship of TRP metabolism to maternal stress and immune status. A total of twenty-four mothers were recruited from Cork University Maternity Hospital: twelve term (>38 weeks) and twelve preterm (<35 weeks). EBM samples were collected on days 7 and 14. Free TRP, Kyn and KynA were measured using HPLC, total TRP using MS, cytokines using the Meso Scale Discovery (MSD) assay system, and cortisol using a cortisol ELISA kit. Although total TRP was higher in preterm EBM in comparison with term EBM (P < 0·05), free TRP levels were lower (P < 0·05). Kyn, KynA and the Kyn:TRP ratio increased significantly in term EBM from day 7 to day 14 (P < 0·05), but not in preterm EBM. TNF-α, IL-6 and IL-8 were higher in day 7 preterm and term EBM in comparison with day 14. There were no significant differences between term and preterm EBM cortisol levels. Increased availability of total TRP, lower levels of free TRP and alterations in the temporal dynamics of TRP metabolism in preterm compared with term EBM, coupled with higher EBM inflammatory markers on day 7, may have implications for the neurological development of exclusively breast-fed preterm infants.

Stability of Cortisol and Cortisone in Human Breast Milk During Holder Pasteurization

Human donor milk is the feeding of choice for preterm infants, when own mother's milk is not available. Holder pasteurization is necessary to secure the safety of donor milk, although it can affect milk quality by reduction of nutritional and bioactive components. Recently, research has focused on the potential role of breast milk glucocorticoids for infant development. At this moment, it is unknown whether pasteurization affects milk glucocorticoid levels. Therefore, we assessed whether Holder pasteurization, the most frequently used method nowadays, reduces breast milk cortisol and cortisone levels, using breast milk samples from 30 women who delivered at term. We found tight correlations between pre- and postpasteurization levels of cortisol (R = 0.99) and cortisone (R = 0.98), and good agreement in Passing and Bablok regression analysis. In conclusion, cortisol and cortisone in human term breast milk are not significantly affected by Holder pasteurization.

Mothers' Consumption of Soy Drink But Not Black Tea Increases the Flavonoid Content of Term Breast Milk: A Pilot Randomized, Controlled Intervention Study

Objective: We performed a pilot RCT to prove the hypothesis that a controlled ingestion of polyphenol-rich beverages (soy drink, decaffeinated black tea) in nutritive dosages by nursing women has an effect on the composition (flavonoid concentration, total antioxidant capacity) of breast milk. Methods: Healthy nursing women were supplemented with either 250 mL of a soy drink (12 mg isoflavones; n = 18), 300 mL decaffeinated black tea (67 mg catechins; n = 18), or 300 mL water (n = 8, control) for 6 days. Milk samples were collected before, during, and after intervention. Flavonoid content (isoflavones/catechins, HPLC) and total antioxidant capacity of milk and test drinks in milk specimens were assessed. Results: Isoflavone content (genistein and daidzein) in breast milk increased up to 12 nmol/L after soy drink consumption; the major flavonoids constituents of black tea (catechin, epicatechin, and respective conjugates) could not be detected in milk samples. With both interventions, the total antioxidant capacity of breast milk was not affected. Conclusions: Mothers' daily consumption of a soy drink considerably increases isoflavone content of breast milk resulting in an estimated daily exposure of 9.6 nmol isoflavones in a 4-month-old suckling infant. Luminal flavanol uptake from black tea consumed by the nursing mother may be too low to affect flavanol concentrations in breast milk.

Breast Milk Stem Cells: Current Science and Implications for Preterm Infants.

The benefits of breast milk are well described, yet the mechanistic details related to how breast milk protects against acute and chronic diseases and optimizes neurodevelopment remain largely unknown. Recently, breast milk was found to contain stem cells that are thought to be involved in infant development. The purpose of this review was to synthesize all available research involving the characterization of breast milk stem cells to provide a basis of understanding for what is known and what still needs further exploration. The literature search was conducted between August and October 2015 using the CINAHL, PubMed, and reference list searching. Nine studies addressed characterization of human breast milk stem cells. Five research teams in 4 countries have published studies on breast milk stem cells. Current research has focused on characterizing stem cells in full-term breast milk. The amount, phenotype, and expression of breast milk stem cells are known to vary between mothers, and they have been able to differentiate into all 3 germ layers (expressing pluripotent characteristics). There is much to learn about breast milk stem cells. Given the potential impact of this research, healthcare professionals should be aware of their presence and ongoing research to determine benefits for infants. Extensive research is needed to further characterize stem cells in breast milk (full-term and preterm), throughout the stages of lactation, and most importantly, their role in the health of infants, and potential for use in regenerative therapies.

Safe management of expressed breast milk: A systematic review.

Expressed breastmilk may be contaminated by viruses and bacteria, or lose nutritional value due to maternal transmission, storage, or handling. Babies may also unintentionally receive expressed breastmilk from a different mother. Conduct a systematic review of evidence from countries with incomes comparable to Australia to summarise the evidence around safe management of expressed breastmilk in terms of the risks of pathogen transmission, contamination and nutritional degradation from storage and transport, disinfection and cleaning procedures, and procedures to minimise misdelivery risk. A search of the international literature sought papers published from 2008 until November 2014. The reference lists of included papers were screened for additional studies. Included papers underwent methodological appraisal and data were extracted. Few pathogens that cause significant morbidity and mortality in developed countries had clear evidence of transmission through breastmilk. Short term storage (up to 96h) at 6.8°C appeared to be safe. Frozen storage was generally safe but results in immunological component degradation. Expert consensus suggests that several acceptable methods of cleaning, including using warm soapy water, or boiling. Breastmilk management policies appear to reduce misdelivery of breastmilk. While there is a generally low risk of pathogen transmission via breastmilk, benefits must be considered against potential disease severity. Short-term refrigeration is generally acceptable for storage and transport. Freezing is often safe but causes degradation of immunological components. Universally, equipment used for expression and storage of breast milk should be well washed and disinfected. Effective breastmilk management policies can reduce risks of misdelivery.

Levels of innate immune factors in preterm and term mothers' breast milk during the 1st month postpartum.

There is a paucity of data on the effect of preterm birth on the immunological composition of breast milk throughout the different stages of lactation. We aimed to characterise the effects of preterm birth on the levels of immune factors in milk during the 1st month postpartum, to determine whether preterm milk is deficient in antimicrobial factors. Colostrum (days 2-5 postpartum), transitional milk (days 8-12) and mature milk (days 26-30) were collected from mothers of extremely preterm (<28 weeks of gestation, n 15), very preterm (28-<32 weeks of gestation, n 15), moderately preterm (32-<37 weeks of gestation, n 15) and term infants (37-41 weeks of gestation, n 15). Total protein, lactoferrin, secretory IgA, soluble CD14 receptor (sCD14), transforming growth factor-β2 (TGF-β2), α defensin 5 (HD5), β defensins 1 (HBD1) and 2, IL-6, IL-10, IL-13, interferon-γ, TNF-α and lysozyme (LZ) were quantified in milk. We examined the effects of lactation stage, gestational age, volume of milk expressed, mode of delivery, parity and maternal infection on milk immune factor concentrations using repeated-measures regression analysis. The concentrations of all factors except LZ and HD5 decreased over the 1st month postpartum. Extremely preterm mothers had significantly higher concentrations of HBD1 and TGF-β2 in colostrum than term mothers did. After controlling for other variables in regression analyses, preterm birth was associated with higher concentrations of HBD1, LZ and sCD14 in milk samples. In conclusion, preterm breast milk contains significantly higher concentrations of some immune proteins than term breast milk.

Proteins in Complementary Food: What Is the Healthiest Level?

Adequate protein consumption in infants is a heavily debated issue. First, it is related to the formation of a new scientific field — “Infant prerequisites of man’s wellness and illness,” which directly indicates that excessive intake of proteins during infancy has long-term consequences and greatly contributes to obesity and chronic infectious diseases in adults; second, it is related to new technologies, which improve the protein component of infant formulas and bring them at par with breast milk in terms of quality and quantity. High protein consumption is related to bottle feeding, because starter and further infant formulas are richer in protein than breast milk. Protein-rich menus trigger production of insulinogenic amino acids, insulin and the insulin-like growth factor (IGF-1). High IFTcombined with branched-chain amino acids (leucine, valine, isoleucine, threonine) activates a set of signalling molecules (mTOR), which are responsible for integrating metabolic and immune response. Repeated activation of mTOR coupled with regular intake of high-protein infant formulas causes health issues in adulthood. Diseases like diabetes type 2, obesity, arterial hypertension, cancer (particularly prostatic cancer), are related to overactivation of the mTOR signalling molecule complex. Intensive consumption of milk in today’s world is the key mTOR activator contributing to an increased risk of lifestyle diseases and triggering the mechanism of their development. The progressing infant formula industry allows to cut protein levels in starter and further infant formulas down to 12 g/l and, respectively, lower the risk of non-infectious diseases in adulthood.

Leukocyte Populations in Human Preterm and Term Breast Milk Identified by Multicolour Flow Cytometry.

BackgroundExtremely preterm infants are highly susceptible to bacterial infections but breast milk provides some protection. It is unknown if leukocyte numbers and subsets in milk differ between term and preterm breast milk. This study serially characterised leukocyte populations in breast milk of mothers of preterm and term infants using multicolour flow cytometry methods for extended differential leukocyte counts in blood.MethodsSixty mothers of extremely preterm (<28 weeks gestational age), very preterm (28–31 wk), and moderately preterm (32–36 wk), as well as term (37–41 wk) infants were recruited. Colostrum (d2–5), transitional (d8–12) and mature milk (d26–30) samples were collected, cells isolated, and leukocyte subsets analysed using flow cytometry.ResultsThe major CD45+ leukocyte populations circulating in blood were also detectable in breast milk but at different frequencies. Progression of lactation was associated with decreasing CD45+ leukocyte concentration, as well as increases in the relative frequencies of neutrophils and immature granulocytes, and decreases in the relative frequencies of eosinophils, myeloid and B cell precursors, and CD16- monocytes. No differences were observed between preterm and term breast milk in leukocyte concentration, though minor differences between preterm groups in some leukocyte frequencies were observed.ConclusionsFlow cytometry is a useful tool to identify and quantify leukocyte subsets in breast milk. The stage of lactation is associated with major changes in milk leukocyte composition in this population. Fresh preterm breast milk is not deficient in leukocytes, but shorter gestation may be associated with minor differences in leukocyte subset frequencies in preterm compared to term breast milk.

A systematic review and meta-analysis of the nutrient content of preterm and term breast milk.

BackgroundBreast milk nutrient content varies with prematurity and postnatal age. Our aims were to conduct a meta-analysis of preterm and term breast milk nutrient content (energy, protein, lactose, oligosaccharides, fat, calcium, and phosphorus); and to assess the influence of gestational and postnatal age. Additionally we assessed for differences by laboratory methods for: energy (measured vs. calculated estimates) and protein (true protein measurement vs. the total nitrogen estimates).MethodsSystematic review results were summarized graphically to illustrate the changes in composition over time for term and preterm milk. Since breast milk fat content varies within feeds and diurnally, to obtain accurate estimates we limited the meta-analyses for fat and energy to 24-hour breast milk collections.ResultsForty-one studies met the inclusion criteria: 26 (843 mothers) preterm studies and 30 (2299 mothers) term studies of breast milk composition. Preterm milk was higher in true protein than term milk, with differences up to 35% (0.7 g/dL) in colostrum, however, after postnatal day 3, most of the differences in true protein between preterm and term milk were within 0.2 g/dL, and the week 10–12 estimates suggested that term milk may be the same as preterm milk by that age. Colostrum was higher than mature milk for protein, and lower than mature milk for energy, fat and lactose for both preterm and term milk. Breast milk composition was relatively stable between 2 and 12 weeks. With milk maturation, there was a narrowing of the protein variance. Energy estimates differed whether measured or calculated, from −9 to 13%; true protein measurement vs. the total nitrogen estimates differed by 1 to 37%.ConclusionsAlthough breast milk is highly variable between individuals, postnatal age and gestational stage (preterm versus term) were found to be important predictors of breast milk content. Energy content of breast milk calculated from the macronutrients provides poor estimates of measured energy, and protein estimated from the nitrogen over-estimates the protein milk content. When breast milk energy, macronutrient and mineral content cannot be directly measured the average values from these meta-analyses may provide useful estimates of mother’s milk energy and nutrient content.

Comparing the fatty acid levels of preterm and term breast milk in Turkish women

Lipids are the main source of calories and considered very important in infant growth. We aimed to compare fatty acid composition of term and preterm breast milk. This is the first study that compares the fatty acid levels of preterm and term breast milk in Turkish women. Breast milk samples were obtained from mothers of term (n = 15) and preterm (n = 15) infants on postnatal days 3, 7, and 28. Fatty acid composition of human breast milk was determined longitudinally by gas-chromatography/mass spectrometry. There Were 31 fatty acids measured in the milk samples. In the first month, 17 fatty acid levels had significant differences. In group comparison, some fatty acids (C14:0, C16:0, C18:1 and C20:5) had significantly increased in the preterm group (P = 0.041, P = 0.046, P = 0.027, P = 0.033, respectively), whereas myristoleic acid (C14:1) and eicosanoic acid (C20:0) had significantly increased in the term group (P = 0.015, P = 0.048, respectively). Term and preterm milk have different compositions of fatty acids. Breast milk composition changes over time. As a general conclusion, breast milk provides the lipid requirements of infants.

Enteral and parenteral lipid requirements of preterm infants.

Lipids provide infants with most of their energy needs. The major portion of the fat in human milk is found in the form of triglycerides, the phospholipids and cholesterol contributing for only a small proportion of the total fat. Long-chain polyunsaturated fatty acids (LC-PUFAs) are crucial for normal development of the central nervous system and have potential for long-lasting effects that extend beyond the period of dietary insufficiency. Given the limited and highly variable formation of docosahexaenoic acid (DHA) from α-linolenic acid, and because DHA is critical for normal retinal and brain development in the human, DHA should be considered to be conditionally essential during early development. In early enteral studies, the amount of LC-PUFAs administered in formula was chosen to produce the same concentration of arachidonic acid and DHA as in term breast milk. Recent studies report outcome data in preterm infants fed formula with DHA content 2-3 times higher than the current concentration. Overall, these studies show that providing larger amounts of DHA supplements is associated with better neurological outcomes and may provide other health benefits. One study further suggests that the smallest babies are the most vulnerable to DHA deficiency and likely to reap the greatest benefit from high-dose DHA supplementation. Current nutritional management may not provide sufficient amounts of preformed DHA during the parenteral and enteral nutrition periods and in very preterm/very low birth weight infants until due date and higher amounts than those routinely used are likely to be necessary to compensate for intestinal malabsorption, DHA oxidation, and early deficit. Recommendations for the healthcare provider are made in order to prevent lipid and more specifically LC-PUFA deficit. Research should be continued to fill the gaps in knowledge and to further refine the adequate intake for each group of preterm infants.

Polyamine levels in breast milk are associated with mothers' dietary intake and are higher in preterm than full‐term human milk and formulas

Polyamine intake from milk is considered essential for post-natal maturation of the immune system and small intestine. The present study aimed to determine polyamine content in human milk after preterm delivery and the association with mothers' dietary intake. In comparison, the polyamine levels were compared with those in term breast milk and some corresponding formulas. Transitional breast milk was collected from 40 mothers delivering after 24-36 weeks of gestation, and from 12 mothers delivering after full term. Food intake was assessed in mothers delivering preterm babies using a 3-day diary. Polyamines were analysed by high-performance liquid chromatography. The dietary intake of polyamines was significantly associated with breast milk content but weaker for spermine than for spermidine and putrescine. Total polyamine level was higher in preterm than term milk and lower in the corresponding formulas. Putrescine, spermidine and spermine contents [mean (SEM)] in preterm milk were 165.6 (25), 615.5 (80) and 167.7 (16) nmol dL⁻¹, respectively, with the levels of putrescine and spermidine being 50% and 25% higher than in term milk. The content of spermine did not differ. Dietary intake of polyamines has an impact on the content in breast milk. The difference between human milk after preterm and term delivery might be considered when using donor human milk for preterm infants. The corresponding formulas had lower contents. Further studies are important for determining the relationship between tissue growth and maturation and optimal intake.

Naturally Occurring Peptides in Human Milk: Identification and Evidence for Antibacterial Action

For over 200 million years, milk has co‐evolved with mammalian infants to be nourishing and immunoprotective. Scientists are now realizing that milk is not simply a mixture of basic nutritional building blocks, but rather a dynamic, active and personal source of nourishment to the human infant. Fragments of milk proteins released during infant digestion have an array of biological functions within the gut and systemically including opioid‐like activity, immune system modulation and antimicrobial action. These peptides are typically inactive within the sequence of the parent protein and only become active when released by proteolysis.This study aimed to identify the extent of milk protein degradation within the breast and identify released peptides with potential bioactivity. Pooled, mature term breast milk was analyzed for presence of protein fragments by nano‐LC Chip Quadrupole Time‐of‐Flight Tandem Mass Spectrometry (Chip‐Q‐TOF). Of the 508 unique milk peptides identified, most (62%) were derived from ß‐casein. Sixty‐two peptides had significant sequence overlap with known bioactive peptides with antimicrobial or immunomodulatory functions. These 500 unique peptides represent a five‐fold increase in the number of naturally occurring peptides identified in the entire history of milk research.Grant Funding Source: USDA

Lipid Needs of Preterm Infants: Updated Recommendations

Long-chain polyunsaturated fatty acids (LCPUFAs) are of nutritional interest because they are crucial for normal development of the central nervous system and have potential long-lasting effects that extend beyond the period of dietary insufficiency. Here we review the recent literature and current recommendations regarding LCPUFAs as they pertain to preterm infant nutrition. In particular, findings that relate to fetal accretion, LCPUFA absorption and metabolism, effects on development, and current practices and recommendations have been used to update recommendations for health care providers. The amounts of long-chain polyunsaturated fatty acids (LCPUFAs) used in early studies were chosen to produce the same concentrations as in term breast milk. This might not be a wise approach for preterm infants, however, particularly for very and extremely preterm infants, whose requirements for LCPUFAs and other nutrients exceed what is normally provided in the small volumes that they are able to tolerate. Recent studies have reported outcome data in preterm infants fed milk with a docosahexaenoic acid (DHA) content 2-3 times higher than the current concentration in infant formulas. Overall, these studies show that providing larger amounts of DHA supplements, especially to the smallest infants, is associated with better neurologic outcomes in early life. We emphasize that current nutritional management might not provide sufficient amounts of preformed DHA during the parenteral and enteral nutrition periods and in very preterm/very low birth weight infants until their due date, and that greater amounts than used routinely likely will be needed to compensate for intestinal malabsorption, DHA oxidation, and early deficit. Research should continue to address the gaps in knowledge and further refine adequate intake for each group of preterm infants.

Investigation of Short-term Variations in Term Breast Milk Composition during Repeated Breast Expression Sessions

Breast milk composition can be affected by several factors, and it can exhibit short-term (weekly) variations. Investigating variations in breast milk composition is important to accurately estimate nutrient requirements of the infant. To investigate short-term changes in breast milk composition between left and right breasts, over a 3-week period within the first 6 months of lactation. The left and right breasts of the mothers of healthy, term infants (n = 23) were simultaneously expressed with an electric breast pump for 15 minutes, on 3 occasions within 3 weeks. Milk samples (5 mL) were collected from the total expression volume of each breast at each session. The macronutrient contents, total solids, and energy content were determined using a mid-infrared human milk analyzer. Mothers (n = 17) measured their 24-hour milk production, and the average 24-hour fat contents were also determined. Over the 3 weekly sessions, no significant changes were found in macronutrient contents. On average, total solids (P = .04) and energy (P = .04) decreased by week 3 of follow-up sessions from 14 to 13 g/100 mL and from 82 to 76 Kcal/100 mL, respectively; however, these changes became insignificant when expression volume was taken into account. The macronutrient concentration was similar for the left and right breasts; however, milk composition varied markedly between mothers. Furthermore, average 24-hour fat content was significantly lower than the mean fat content from a single expression session (P < .01). Our findings highlight that when determining the nutritional adequacy of a mother's milk, assuming an average concentration requires caution. The study findings illustrate the importance of using average 24-hour fat content of milk to obtain representative measures of infant energy intake.