Composition and Variation of Macronutrients, Immune Proteins, and Human Milk Oligosaccharides in Human Milk From Nonprofit and Commercial Milk Banks

Investigating Milk Fat Globule Structure, Size, and Functionality after Thermal Processing and Homogenization of Human Milk

Human milk provides bioactive compounds such as milk fat globules (MFGs), which promote brain development, modulate the immune system, and hold antimicrobial properties. To ensure microbiological safety, donor milk banks apply heat treatments. This study compares the effects of heat treatments and homogenization on MFG's physicochemical properties, bioactivity, and bioavailability. Vat pasteurization (Vat-PT), retort (RTR), and ultra-high temperature (UHT) were performed with or without homogenization. UHT, RTR, and homogenization increased the colloidal dispersion of globules, as indicated by increased zeta potential. The RTR treatment completely inactivated xanthine oxidase activity (a marker of MFG bioactivity), whereas UHT reduced its activity by 93%. Interestingly, Vat-PT resulted in less damage, with 28% activity retention. Sialic acid, an important compound for brain health, was unaffected by processing. Importantly, homogenization increased the in vitro lipolysis of MFG, suggesting that this treatment could increase the digestibility of MFG. In terms of color, homogenization led to higher L* values, indicating increased whiteness due to finer dispersion of the fat and casein micelles (and thus greater light scattering), whereas UHT and RTR increased b* values associated with Maillard reactions. This study highlights the nuanced effects of processing conditions on MFG properties, emphasizing the retention of native characteristics in Vat-PT-treated human milk.

A comprehensive evaluation of milk protein molecular weight distribution based on exclusion chromatography dataset

Molecular weight is one of the main characteristic parameters of proteins, which is the basis for the functional properties of milk protein. This research aims at establishing molecular weight distribution pattern of milk protein based on exclusion chromatography. The method selected Na3PO4-Na2SO4 (0.1 M, pH 6.7) buffer as the mobile phase and detected at 220 nm by HPLC-UV. The protein molecular weight distributions were determined and compared for human milk, bovine milk, and infant formula. The proportion of macromolecular proteins is much higher in infant formula compared to human or bovine milk. The protein molecular weights of human and bovine milk are significantly different around 90, 20, 14, and 2 kDa. The results provide holistic compare of bovine milk, human milk, and infant formula through protein molecular distribution. The new evaluation indicators for protein will drive technological simulation of infant formula.

Effects of pasteurization on osteopontin concentrations in human breastmilk

BACKGROUND

Osteopontin (OPN) is an important breastmilk protein involved in infant intestinal, immunological, and brain development. However, little is known about how common milk pasteurization and storage techniques affect this important bioactive protein.

METHODS

Human milk osteopontin concentration was measured in single-donor fresh (n = 1) or frozen (n = 20) breastmilk, pooled Holder-pasteurized donor breastmilk (n = 11), and a shelf-stable (retort pasteurized) breastmilk product (n = 2) by ELISA. Single-donor breastmilk samples were subjected to pasteurization and/or freezing before measuring osteopontin concentrations.

RESULTS

Holder pasteurization of breastmilk resulted in an ∼50% decrease in osteopontin concentration within single-donor samples. Breastmilk from mothers of preterm infants trended toward higher osteopontin concentration than mothers of term infants; however, samples from preterm mothers experienced greater osteopontin degradation upon pasteurization. A commercial breastmilk product that underwent retort pasteurization had lower osteopontin concentration than a Holder-pasteurized pooled breastmilk product. Finally, freezing breastmilk prior to Holder pasteurization resulted in less osteopontin degradation than Holder pasteurization prior to freezing.

CONCLUSIONS

Commonly used breastmilk pasteurization and storage techniques, including freezing and Holder pasteurization, decrease the concentration of the bioactive protein osteopontin in human breastmilk. Holder pasteurization reduced osteopontin concentration by an average of 63%, while freezing resulted in an 8-12% decrease.

IMPACT

Pasteurization of human breastmilk significantly decreases the concentration of the bioactive protein osteopontin. Use of both pasteurization and freezing techniques for breastmilk preservation results in greater loss of osteopontin. This study presents for the first time an analysis of osteopontin concentrations in single-donor pasteurized milk samples.

Label-Free quantitation of milk oligosaccharides from different mammal species and heat treatment influence

Milk oligosaccharides (MOs) exhibit significant variations in concentrations and patterns among different species. However, there is limited knowledge about milk oligosaccharides in domestic animals and the impact of heat treatment on them. Here, we developed an LC-ESI-MS/MS method to analyze 11 milk oligosaccharides in 7 distinct species simultaneously. The results showed that human milk presented a completely different composition pattern of milk oligosaccharides from animals. In detail, animal milk predominantly contained sialylated oligosaccharides, and human milk had high levels of fucosylated neutral oligosaccharides. Notably, sheep milk exhibited similarities to human milk in terms of oligosaccharides composition. Then, the milk samples from dairy cows were treated with two common industrial heat treatments. We found that 65 °C treatment had no significant effect on the concentration of milk oligosaccharides, whereas 135 °C heating was associated with their decline, suggesting that high temperatures should be avoided in the processing of oligosaccharides supplemented/enriched products.

An equitable, community-engaged translational framework for science in human lactation and infant feeding-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 5

Human milk is the ideal source of nutrition for most infants, but significant gaps remain in our understanding of human milk biology. As part of addressing these gaps, the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project Working Groups 1-4 interrogated the state of knowledge regarding the infant-human milk-lactating parent triad. However, to optimize the impact of newly generated knowledge across all stages of human milk research, the need remained for a translational research framework specific to the field. Thus, with inspiration from the simplified environmental sciences framework of Kaufman and Curl, Working Group 5 of the BEGIN Project developed a translational framework for science in human lactation and infant feeding, which includes 5 nonlinear, interconnected translational stages, T1: Discovery; T2: Human health implications; T3: Clinical and public health implications; T4: Implementation; and T5: Impact. The framework is accompanied by 6 overarching principles: 1) Research spans the translational continuum in a nonlinear, nonhierarchical manner; 2) Projects engage interdisciplinary teams in continuous collaboration and cross talk; 3) Priorities and study designs incorporate a diverse range of contextual factors; 4) Research teams include community stakeholders from the outset through purposeful, ethical, and equitable engagement; 5) Research designs and conceptual models incorporate respectful care for the birthing parent and address implications for the lactating parent; 6) Research implications for real-world settings account for contextual factors surrounding the feeding of human milk, including exclusivity and mode of feeding. To demonstrate application of the presented translational research framework and its overarching principles, 6 case studies are included, each illustrating research gaps across all stages of the framework. Applying a translational framework approach to addressing gaps in the science of human milk feeding is an important step toward the aligned goals of optimizing infant feeding across diverse contexts as well as optimizing health for all.

Human Milk Oligosaccharides Are Associated with Lactation Stage and Lewis Phenotype in a Chinese Population

Background: Human milk oligosaccharides (HMOs) are the third most abundant component of human milk. Various factors may affect the concentration of HMOs, such as the lactation period, Lewis blood type, and the maternal secretor gene status. Objectives: The purpose of this study is to investigate factors associated with HMO concentrations in Chinese populations. Methods: A sub-sample of 481 was randomly selected from a large cross-sectional study in China (n = 6481) conducted in eight provinces (Beijing, Heilongjiang, Shanghai, Yunnan, Gansu, Guangdong, Zhejiang, and Shandong) between 2011 and 2013. HMO concentrations were determined by a high-throughput UPLC-MRM method. Various factors were collected through face-to-face interviews. Anthropometric measurement was conducted by trained staff. Results: Median total HMO concentration was 13.6 g/L, 10.7 g/L, and 6.0 g/L for colostrum, transitional milk, and mature milk, respectively. HMO concentration decreased significantly as the lactation period increased (p < 0.0001). There were significant differences of average total HMO concentration between secretor mothers and non-secretor mothers (secretor 11.3 g/L vs. non-secretor 5.8 g/L, p < 0.0001). There were significant differences of average total HMO concentrations among three Lewis blood types (p = 0.003). Comparing with the concentration of total oligosaccharides of Le+ (a−b+), average of total oligosaccharides concentrations increased by 3.9 (Le+ (a+b−), p = 0.004) and 1.1 g/L (Le− (a−b−), p = 0.049). The volume of breast milk expressed and the province the mother came from affected the concentration of total oligosaccharides (all p < 0.0001). Maternal BMI (p = 0.151), age (p = 0.630), prematurity (p = 0.850), mode of delivery (p = 0.486), infants’ gender (p = 0.685), maternal education level (p = 0.989), maternal occupation (p = 0.568), maternal allergic history (p = 0.370), maternal anemia (p = 0.625), pregnancy-induced hypertension (p = 0.739), gestational diabetes (p = 0.514), and parity (p = 0.098) were not significantly correlated with the concentration of milk oligosaccharides. The concentrations of 2′-fucosyllactose (2′-FL), lacto-N-neotetraose (LNnT), sialyllacto-N-tetraose c (LSTc), lacto-N-fucopentaose I (LNFP-I), disialylated lacto-N-tetraose (DSLNT), difucosyl-para-lacto-N-neohexaose (DFpLNnH), difucosyl-lacto-N-hexaose (DFLNH[a]), and 3-sialyllactose (3′-SL) showed a gradual downward trend, while the concentration of 3-fucosyllactose (3-FL) showed a gradual upward trend among three lactation stages (p < 0.05). Conclusions: The concentration of HMOs changes throughout lactation, and it varies between different HMOs. HMO concentrations differed between lactation stage, maternal secretor gene status, Lewis blood type, volume of breast milk expressed, and the province the mother came from. Prematurity, mode of delivery, parity, infants’ gender, and maternal characteristics did not affect the HMO concentration. Geographical region may be not associated with HMOs concentration in human milk. There may be a mechanism for co-regulation of the secretion of some of the oligosaccharides such as 2′FL vs. 3FL, 2′FL vs. LNnT, and lacto-N-tetraose (LNT).

Dilemmas in human milk fortification

Fortification of human milk is the standard of care for very low birth weight (VLBW) infants and is required to support adequate postnatal growth and development. Achieving adequate growth velocity and preventing growth faltering is critical for the developing neonatal brain and optimizing long-term neurodevelopmental outcomes. Mother's milk is the gold standard nutrition to feed preterm infants, however, it does not provide the nutrients needed to support the growth of VLBW infants. After the decision is made to use mother's milk (if available) or alternatively, donor human milk, many dilemmas exist with regards to additional treatment decisions surrounding the type of fortification to use, when to fortify, and the duration of fortification. In this article, we will review the differences in mother's milk compared to donor milk, the different types of human milk fortifiers, the optimal timing of fortification, and discuss when to discontinue human milk fortification.

Use of human milk and fortification in the NICU

Human milk is the gold standard to provide nutritional support for all healthy and sick newborn infants including the very low birth weight (VLBW) infant (<1500 g). It has both nutritional and anti-infective properties which are especially important for these infants at risk for sepsis and necrotizing enterocolitis. Human milk alone is insufficient to meet the nutritional needs for VLBW infants, especially protein and minerals. There is a conundrum between achieving the nutritional, immunologic, developmental, psychological, social, and economic benefit with human milk vs. the inadequate growth with unfortified human milk for VLBW leading to nutritional inadequacy, growth failure and poor neurodevelopmental outcome. The use of multicomponent fortifiers to increase calories and provide additional protein, vitamins, and minerals has been associated with short-term benefits in growth. Most current fortifiers are derived from cow's milk, however there are concerns regarding a possible association between the use of cow's milk-based fortifier and NEC. There is also an exclusive human milk diet with a fortifier derived solely from human milk. There are three approaches for fortifying human milk and include fixed dosage or "blind fortification", adjustable fortification using the blood urea nitrogen as a surrogate for protein nutriture to modify dosage of fortification, and targeted, individualized fortification that is based on periodic human milk analysis.

Targeted fortification with human milk analysis: An opportunity for innovation

Human milk's variable macronutrient composition is a necessary consideration when caring for very low birthweight infants. Targeted fortification is the practice of fortifying human milk using its known composition from human milk analysis, rather than its assumed macronutrient values. Utilization of human milk analyzers to measure the protein, fat, lactose, and energy composition within human milk samples has allowed the translation of this practice into the clinical setting. This review discusses the rationale of why targeted fortification is an important practice, what barriers exist in its implementation in the clinical setting, and what research gaps remain to be addressed.

Evolution of Preterm Infant Nutrition from Breastfeeding to an Exclusive Human Milk Diet: A Review

The benefits of feeding human milk to human infants are well-established. Preterm infants, particularly those born with very low birthweight (VLBW; <1,500 g), are a uniquely vulnerable population at risk for serious, life-threatening complications as well as disruptions in normal growth and development that can affect their lives into adulthood. Feeding VLBW preterm infants an exclusive human milk diet (EHMD) from birth that consists of the mother's own milk or donor human milk plus a nutritional fortifier made exclusively from human milk has been associated with a reduction in morbidity and mortality and improved early growth and developmental metrics. Preliminary evidence suggests that the health benefits of adopting an EHMD (or avoiding cow milk products) early in life may last into adulthood. This review briefly summarizes the history of breastfeeding and describes the available evidence on the benefits of an EHMD among VLBW preterm infants as well as the importance of high-quality manufacturing standards for producing safe and effective human milk-based products.

Enteral Nutrition: The Intricacies of Human Milk from the Immune System to the Microbiome

In 2012, the American Academy of Pediatrics stated that all preterm infant diets should consist of human milk (mother's own milk or pasteurized donor human milk). The clinical reasons supporting this policy are many, including reducing infections and retinopathy of prematurity, decreased neonatal intensive care unit length of stay, subsequent readmissions, a decrease in mortality, and improved neurodevelopmental outcomes. This article focuses on human milk, its composition and bioactive factors, and how it affects the gut-brain axis through the microbiome. We examine how differences between mother's own milk and pasteurized donor human milk affect the premature infant.

Human Milk Fortification: A Practical Analysis of Current Evidence

Human milk (HM) with appropriate fortification is the recommended nutrition for very low birth weight (VLBW) infants. Fortification provides additional nutrients, vitamins, and minerals to support the growing preterm infant during critical periods of development. This article discusses the variability of HM including differences between maternal and pasteurized donor human milk (DHM), fortification of HM through the use of single- and multi-nutrient fortifiers, and clinical controversies including the timing of fortification, volume of feedings, and future innovations in HM fortification.

Influence of Homogenization in the Physicochemical Quality of Human Milk and Fat Retention in Gastric Tubes

BACKGROUND

The retention of human milk nutrients in gastric tubes used to feed premature infants is a challenge to be overcome.

RESEARCH AIMS

To evaluate (1) the performance of six homogenizers (mixing processor, piston valve, ultrasonic bath, ultraturrax, stirring mixer, and ultrasound probe) for the fat retention reduction in gastric tubes; (2) the influence of the best homogenization conditions on the fatty acid and protein profiles of human milk; and (3) the cost/benefit ratio for the inclusion of homogenization as a new step in human milk processing.

METHODS

The influence of different levels and times of homogenization on reducing fat retention of human milk in probes was evaluated in this comparative prospective cross-sectional study. After homogenization, human milk flowed through a gavage and infusion pump apparatus used for feeding. Fat content was quantified before and after feeding. The techniques that reduced fat globule sizes and/or promoted a lower percentage of fat holding were evaluated for efficiency, variations in the fatty acid and protein profiles, and energy density and operating costs.

RESULTS

Homogenization led to a reduction in fat retention in feeding probes. The mixer processor and the ultrasound probe reduced fat retention by 99.23% (SD = 0.07) and 99.95% (SD = 0.02), respectively, and did not negatively influence fatty acid and protein profiles. The mixer processor demonstrated low energy density and low cost for human milk processing.

CONCLUSION

Homogenization promoted reduced fat retention in the feed probe and could help maintain fat nutrients of human milk during enteral feeding.

Natural Association of Lysozyme and Casein Micelles in Human Milk

Using reversed phase high-performance liquid chromatography with ultraviolet (UV) detection and electrospray ionization (ESI)-quadrupole time-of-flight mass spectrometry (RP-HPLC-UV-ESI-Q-TOF), the lysozyme content in the milk of 10 volunteering mothers was quantified, ranging from 29 to 96 μg/mL. Following ultracentifugation, it was found that the lysozyme in human milk, unlike other whey proteins, is mainly bound to casein micelles (ca. 75%). The enzymatic activity of human lysozyme, measured as lytic activity against cell walls of Micrococcus lysodeikticus, was similar for the micelle-bound and free protein, indicating that the micellar structure should not affect the antibacterial activity of lysozyme. The results indicate that lysozyme is an integral component of casein micelles in human milk.

Effect of microwave and convection heating on selected nutrients of human milk

The aim of this study was to determine the influence of the microwave heating method (MWH) on selected determinants of the nutritional value of human milk (HM) and compare to the effect exerted by the standard convection heating (CH) method, including holder pasteurization (HoP). It was showed that using MWH under conditions assumed to ensure microbiological safety, changes in the level of the nutrients were not observed. In these conditions concentration of fatty acids (FAs), lipid peroxides (LP) and α-lactalbumin (α-La) were on a similar level as in raw milk, and furosine was not formed. MWH treatment of HM led to slight increase in the malonaldehyde (MDA) and protein carbonyls (PC) content. However, MDA content in HM as a result of MWH was lower than after application CH.

Investigating changes of proteome in the bovine milk serum after retort processing using proteomics techniques

The objective of this study was to investigate the changes of the proteins in bovine milk serum after retort processing by label-free quantification proteomics techniques. A total of 96 and 106 proteins were quantified in control group (CG) and retort group (RG), respectively. Hierarchical clustering analysis of the identified milk serum proteins showed a decrease in the abundance of most proteins, such as serum albumin, lactoperoxidase, lactotransferrin, and complement C3, and an increase in the abundance of other proteins such as κ-casein, lipocalin 2, and Perilipin. Student's t-test showed 21 proteins significantly differential abundance between CG and RG (p < .05), of which intensity-based absolute quantification (iBAQ) of five proteins decreased and iBAQ of 16 proteins increased. Bioinformatics analysis demonstrated that retort processing increased the digestibility of proteins, but this improvement was offset by a decrease in the digestibility of proteins caused by protein modification. Our results provide insight into the proteome of retort sterilized milk for the first time. Given the extremely high security of retort sterilized milk, the proteome of bovine milk serum changes after retort sterilization exposed in this study will contribute to the formula design of retort sterilized milk products.

The Impact of Homogenization on Donor Human Milk and Human Milk-Based Fortifiers and Implications for Preterm Infant Health

An exclusive human milk diet (EHMD) has been shown to reduce health complications of prematurity in infants born weighing ≤1250 g compared with cow milk-based diets. Accordingly, the number of available human milk (HM)-based nutritional products continues to increase. Newly available products, and those reportedly soon to enter the market, include homogenized donor HM and homogenized HM-based fortifiers. Existing literature demonstrating the benefits of an EHMD, however, is limited to non-homogenized HM-based products. Herein, we summarize existing evidence on the impact of homogenization on HM, with a particular focus on changes to the macromolecular structure of the milk fat globule and the subsequent impact on digestion kinetics. We use these published data to create a conceptual framework for the potential implications of homogenized HM-based nutritional products on preterm infant health. Importantly, we underscore that the safety and efficacy of homogenized HM-based products warrant investigation.

Critical examination of relationships between early growth and childhood overweight in extremely preterm infants

OBJECTIVES

To identify the prevalence and risk factors for childhood overweight and obesity (OWO) at 3-year corrected age in children born <1500 g <29 weeks gestation.

STUDY DESIGN

A multicentre retrospective cohort study for preterm infants admitted to neonatal intensive care units between 2001 and 2014.

RESULTS

Data were available for 911 (89.4%) of the 1019 infants who met the inclusion criteria. Of them, 22 (2.4%) had OWO. There were no associations between OWO and being small for gestational age (RR = 1.3, 95% confidence interval (CI): 0.3-5.4) or weight <10th percentile at 36 weeks (RR = 1.1, 95% CI: 0.4-2.8). OWO was associated with low maternal education (RR = 7.4, 95% CI: 2.1-26), maternal diabetes (RR = 5.2, 95% CI: 1.9-15) and neonatal brain injury (RR = 4.9, 95% CI: 1.8-14). Adjusting for concurrent child weight at 3 years of age resulted in an overadjustment bias.

CONCLUSION

Small size at birth or at 36 weeks gestation in extremely preterm infants is not associated with increased risk of early childhood overgrowth or obesity.

CLINICAL TRIAL REGISTRATION

NCT03064022.

Developing global guidance on human milk banking

Donor human milk is recommended by the World Health Organization both for its advantageous nutritional and biological properties when mother’s own milk is not available and for its recognized support for lactation and breastfeeding when used appropriately. An increasing number of human milk banks are being established around the world, especially in low- and middle-income countries, to facilitate the collection, processing and distribution of donor human milk. In contrast to other medical products of human origin, however, there are no minimum quality, safety and ethical standards for donor human milk and no coordinating global body to inform national policies. We present the key issues impeding progress in human milk banking, including the lack of clear definitions or registries of products; issues around regulation, quality and safety; and ethical concerns about commercialization and potential exploitation of women. Recognizing that progress in human milk banking is limited by a lack of comparable evidence, we recommend further research in this field to fill the knowledge gaps and provide evidence-based guidance. We also highlight the need for optimal support for mothers to provide their own breastmilk and establish breastfeeding as soon as and wherever possible after birth.

Synthesis as an Expanding Resource in Human Milk Science

Few classes of natural products rival the structural audacity of oligosaccharides. Their complexity, however, has stood as an immense roadblock to translational research, as access to homogeneous material from nature is challenging. Thus, while carbohydrates are critical to the myriad functional and structural aspects of the biological sciences, their behavior is largely descriptive. This challenge presents an attractive opportunity for synthetic chemistry, particularly in the area of human milk science. First, there is an inordinate need for synthesizing homogeneous human milk oligosaccharides (HMOs). Superimposed on this goal is the mission of conducting syntheses at scale to enable animal studies. Herein, we present a personalized rumination of our involvement, and that of our colleagues, which has led to the synthesis and characterization of HMOs and mechanistic probes. Along the way, we highlight chemical, chemoenzymatic, and synthetic biology based approaches. We close with a discussion on emergent challenges and opportunities for synthesis, broadly defined, in human milk science.

Tailoring Human Milk Oligosaccharides to Prevent Necrotising Enterocolitis Among Preterm Infants

Necrotising enterocolitis (NEC) is a devastating disease affecting preterm infants, with little improvement in mortality rates and treatment strategies in the last 30 years. Human milk oligosaccharides (HMOs) are emerging as a potential preventive therapy, with multiple protective functions postulated. Our aim is to summarise the evidence concerning the role of HMOs in NEC development and emerging strategies to tailor the delivery of HMOs to preterm infants. Most research efforts to date have focused on supplementing preterm infants with simple oligosaccharides, which are structurally different to HMOs and derived mainly from plants. Clinical trials demonstrate limited benefits for NEC prevention arising from the use of these supplements. Alternative strategies under investigation include optimising HMOs for infants receiving donor human milk, concentrating oligosaccharides from donor human milk and from animal milks, as well as more sophisticated synthetic oligosaccharide production strategies. Critically, high quality evidence to support implementation of any of these approaches in the neonatal unit is lacking. Whether it is a specific HMO alone or a combination of HMOs that exert protective effects remains to be elucidated. Further challenges include how best to manufacture and administer oligosaccharides whilst retaining bioactivity and safety, including evaluation of the long-term effects of altering the balance of HMOs and gut microbiota in preterm infants. While several human clinical trials are underway, further research is needed to understand whether a tailored approach to oligosaccharide supplementation is beneficial for preterm infants.

Do Maternal Factors and Milk Expression Patterns Affect the Composition of Donor Human Milk?

A primary role of Human Milk Banks (HMBs) is to provide human milk (HM) for preterm infants and to support the mothers of these infants as they establish their own milk supply. A better understanding of the variation in the energy and macronutrients contents of donor human milk (DHM) potentiates targeted nutrition for preterm babies. Therefore, the aim of this study was to assess the variability of energy and macronutrients content in DHM and to investigate the impact of maternal factors and feeding practices on the nutritional value of DHM. The study involved 49 donors registered in the HMB in the Holy Family Hospital in Warsaw, Poland. Samples from each donor were pooled within a maximum of two weeks. The composition of DHM, including energy content, protein, fat, and carbohydrate concentrations, was analyzed using the Miris Human Milk Analyzer. The analyses were performed before the pasteurization process. The mean time of milk donation to HMB was 13.2 ± 6.0 weeks. There were no significant differences in energy and macronutrients contents of DHM in the beginning and at the end of milk donation to HMB, however, HM fat concentration was positively correlated with afternoon feedings (r = 0.289, p = 0.044). The method of feeding (breastfeeding vs. feeding only expressed milk) also did not impact the nutritional value of DHM. Future research for the DHM should include a further cross-sectional observational study with the collection of detailed donor information and characteristics of milk expression and feeding practices to further evaluate the pooling processes and the effect on DHM composition.

Effects of milk banking procedures on nutritional and bioactive components of donor human milk

Pasteurized donor human milk is in wide use for preterm infants in neonatal intensive care units when maternal milk is unavailable. Pasteurization of donor milk is required to prevent bacterial contamination, and multiple methods are used in the non-profit and commercial milk banking industries. Pasteurization results in changes in the nutrient and bioactive components in donor milk compared to unpasteurized human milk, and these changes vary by the type of pasteurization process. Other milk bank practices including freezing of milk, pooling of milk from multiple donors and use of pre-processing macronutrient analysis also affect the nutritional composition of donor milk. This review compiles evidence regarding three common pasteurization techniques for donor milk: Holder pasteurization, vat pasteurization, and retort pasteurization and their effects on the nutritional content and bioactive factors in human milk. It also includes review of literature investigating the impact of freezing and storage, and best practices for multi-donor milk pooling.

Goat Milk Oligosaccharides: Their Diversity, Quantity, and Functional Properties in Comparison to Human Milk Oligosaccharides

Human milk is considered the golden standard in infant nutrition. Free oligosaccharides in human milk provide important health benefits. These oligosaccharides function as prebiotics, immune modulators, and pathogen inhibitors and were found to improve barrier function in the gut. Infant formulas nowadays often contain prebiotics but lack the specific functions of human milk oligosaccharides (hMOS). Milk from domesticated animals also contains milk oligosaccharides but at much lower levels and with less diversity. Goat milk contains significantly more oligosaccharides (gMOS) than bovine (bMOS) or sheep (sMOS) milk and also has a larger diversity of structures. This review summarizes structural studies, revealing a diversity of up to 77 annotated gMOS structures with almost 40 structures fully characterized. Quantitative studies of goat milk oligosaccharides range from 60 to 350 mg/L in mature milk and from 200 to 650 mg/L in colostrum. These levels are clearly lower than in human milk (5-20 g/L) but higher than in other domesticated dairy animals, e.g., bovine (30-60 mg/L) and sheep (20-40 mg/L). Finally, the review focuses on demonstrated and potential functionalities of gMOS. Some studies have shown anti-inflammatory effects of mixtures enriched in gMOS. Goat MOS also display prebiotic potential, particularly in stimulating growth of bifidobacteria preferentially. Although functional studies of gMOS are still limited, several structures are also found in human milk and have known functions as immune modulators and pathogen inhibitors. In conclusion, goat milk constitutes a promising alternative source for milk oligosaccharides, which can be used in infant formula.

Enteral Nutrition in Pediatric Short-Bowel Syndrome

Pediatric intestinal failure (IF) is the critical reduction of intestinal mass or function below the amount necessary for normal growth in children. Short-bowel syndrome (SBS) is the most common cause of IF in infants and children and is caused by intestinal resection. Enteral autonomy and freedom from parenteral nutrition is the mainstay of nutrition management in SBS. The goal is to achieve intestinal adaptation while maintaining proper growth and development. Treatment is variable, and there remains a paucity of evidence to draw well-informed conclusions for the care of individuals in this complex population. Physiological principles of enteral nutrition and practical recommendations for advancing the diet of patients with pediatric SBS are presented. Emerging trends in nutrition management, such as the growing interest in blending diets and the impact on SBS, are reviewed. Finally, the influence of the microbiome on enteral tolerance and small bowel bacterial overgrowth are considered.

The Nutritional Composition and Energy Content of Donor Human Milk: A Systematic Review

The American Academy of Pediatrics recommends donor human milk (DHM) as the preferred feeding strategy for preterm infants when the milk of the mother is unavailable, based on conclusive evidence of lower rates of necrotizing enterocolitis with DHM feedings compared with preterm infant formula. The nutritional composition of DHM may differ from maternal milk for many reasons including differences in maternal characteristics, milk collection methods, and the impact of donor milk banking practices. The purpose of this systematic review is to examine the literature regarding research on the fat, protein, carbohydrate, vitamin, and mineral composition of DHM obtained through nonprofit milk banks or commercial entities. PubMed, CINAHL, and Scopus databases were searched for articles published between 1985 and 30 April, 2019. In total, 164 abstracts were screened independently by 2 investigators, and 14 studies met all inclusion criteria. Studies were predominantly small (<50 samples) and measured macronutrients. Few studies assessed vitamins and minerals. Information bias was prevalent due to the use of a variety of analytical methods which influence accuracy and cross-study comparisons. Other sources of information bias included missing information regarding methods for protein and calorie assessment. Despite these limitations, existing research suggests the potential for 2-fold and greater differences in the fat, protein, and energy composition of DHM, with mean values for energy and fat often below clinical reference values expected for human milk. Further research is warranted regarding the nutritional composition of DHM, with a prioritization on measuring macronutrients and micronutrients using established reference methods.

Fat and Protein Variability in Donor Human Milk and Associations with Milk Banking Processes

Background: The impact of milk banking processes on macronutrient variability in donor human milk (DHM) is largely unknown. Objective: To gain a better understanding of fat and protein composition in DHM and assess potential relationships with modifiable milk bank processes. Methods: Samples of raw, pooled DHM were collected from 20 milk banks (n = 300) along with the following processing attributes: if macronutrient analysis was used to select donors for pooling (target pooling; yes/no), number of donors per pool, pooling container material (glass/plastic/other), and method for mixing during bottling (manual/mechanical). Fat and protein were assessed. Homoscedasticity was assessed and magnitude of the spread was quantified. Results: Fat ranged from 1.9 to 6.1 g/dL (n = 298) and protein ranged from 0.7 to 1.4 g/dL (n = 300). Variability in fat was significantly lower in samples that had been target pooled (p = 0.04), contained more donors per pool (p < 0.001), and had been mixed mechanically (p < 0.001). Variability in protein was significantly lower in samples that contained more donors per pool (p = 0.001). In a stratified analysis, increasing the number of donors per pool only reduced nutrient variability in samples that were not target pooled. Conclusion: For milk banks that do not target pool, using a greater number of donors in a pool may reduce fat and protein variability.

Does the contribution of human milk oligosaccharides to the beneficial effects of breast milk allow us to hope for an improvement in infant formulas?

Human milk is a source of nutrients and contains many distinct bioactive components. Among these, human milk oligosaccharides (HMOs) have attracted considerable attention and are being investigated as a "novel foods". Human milk is unique in its oligosaccharide composition. Recent research has focused on the complexity of HMOs by highlighting their diversity, structural variability, concentration variance, and structure-function relationships. In vitro and in vivo studies have demonstrated that HMOs drive infant gut microbiota, improve intestinal barrier functions, and modulate cell receptor signaling, thereby contributing to the development of infant immunity. These studies, combined with epidemiological data, indicate that some HMO may confer health benefits by preventing infections and diseases such as necrotizing enterocolitis and allergies. However, randomized controlled trials are restricted to structurally simple compounds such as 2' fucosyllactose and lacto-N-neotetraose. More controlled clinical trials are needed to justify routine supplementation of formula. It is felt that a better understanding of the role of HMOs leading to the development of inexpensive methods for large-scale HMO production is needed.

The Impact of Dietary Fucosylated Oligosaccharides and Glycoproteins of Human Milk on Infant Well-Being

Apart from optimal nutritional value, human milk is the feeding strategy to support the immature immunological system of developing newborns and infants. The most beneficial dietary carbohydrate components of breast milk are human milk oligosaccharides (HMOs) and glycoproteins (HMGs), involved in both specific and nonspecific immunity. Fucosylated oligosaccharides represent the largest fraction of human milk oligosaccharides, with the simplest and the most abundant being 2'-fucosyllactose (2'FL). Fucosylated oligosaccharides, as well as glycans of glycoproteins, as beneficial dietary sugars, elicit anti-adhesive properties against fucose-dependent pathogens, and on the other hand are crucial for growth and metabolism of beneficial bacteria, and in this aspect participate in shaping a healthy microbiome. Well-documented secretor status related differences in the fucosylation profile of HMOs and HMGs may play a key but underestimated role in assessment of susceptibility to fucose-dependent pathogen infections, with a potential impact on applied clinical procedures. Nevertheless, due to genetic factors, about 20% of mothers do not provide their infants with beneficial dietary carbohydrates such as 2'-FL and other α1,2-fucosylated oligosaccharides and glycans of glycoproteins, despite breastfeeding them. The lack of such structures may have important implications for a wide range of aspects of infant well-being and healthcare. In light of the above, some artificial mixtures used in infant nutrition are supplemented with 2'-FL to more closely approximate the unique composition of maternal milk, including dietary-derived fucosylated oligosaccharides and glycoproteins.

Comparative study of preterm infants fed new and existing human milk fortifiers showed favourable markers of gastrointestinal status

Aim

This study examined the influence of different human milk fortifiers on biomarkers of gastrointestinal immaturity and inflammation in preterm infants.

Methods

We report secondary outcomes from a controlled, double‐blind, randomised, parallel group study conducted from 2011 to 2014 in neonatal intensive care units at 11 metropolitan hospitals in France, Belgium, Germany, Switzerland and Italy. Preterm infants born at up to 32 weeks or weighing up to 1500 g were randomised to a new powdered human milk fortifier (n = 77) or a control fortifier (n = 76) for a minimum of 21 days. We analysed faecal markers of gut inflammation, namely alpha‐1 antitrypsin and calprotectin, and maturity, namely elastase‐1.

Results

Faecal alpha‐1 antitrypsin was slightly lower in the new than control fortifier group after 21 days of full enteral feeding, with a geometric mean and standard deviation of 1.52 ± 1.32 vs 1.82 ± 1.44 mg/g stools (P = .01). There was no significant difference in faecal calprotectin (median [Q1‐Q3] of 296 [136‐565] μg/g stools in both groups combined at study day 21). Faecal elastase‐1 was lower in the new fortifier than control fortifier group (202.5 ± 1.6 vs 257.7 ± 1.5 μg/g stools, P = .016).

Conclusion

Mean values for each parameter were within the ranges in healthy term infants, indicating favourable markers of gastrointestinal status in both groups. In addition, for faecal calprotectin, the relatively high concentration observed in preterm infants fed fortified human milk suggests that the threshold level for detecting necrotising enterocolitis should be revised.

Accuracy and Reliability of Infrared Analyzers for Measuring Human Milk Macronutrients in a Milk Bank Setting

BACKGROUND

Infrared (IR) analysis is an emerging technology that may be a useful tool for milk banks to manage the nutrient variability in donor human milk.

OBJECTIVE

To evaluate the accuracy, reliability, and comparability of commercial infrared analyzers for measuring human milk macronutrients in a milk bank setting.

METHODS

Three nonprofit milk banks received blinded test kits of human milk that had been assessed using reference methods. Four infrared instruments were used to measure macronutrients as follows: 1 filtered mid-IR, 2 Fourier-transformed full-spectra mid-IR, and 1 near-IR. Twenty-five unique samples were read concurrently for the accuracy arm. An identical sample was read daily for 1 mo for the reliability arm.

RESULTS

Values for R 2 describing relationships with reference methods for total fat, crude protein, and lactose, were as follows: filtered mid-IR, 0.98, 0.94, and 0.48; Fourier-transformed full-spectra mid-IR, 0.97, 0.93, and 0.36 for instrument 1 and 0.98, 0.98, and 0.31 for instrument 2; and near-IR 0.93, 0.93, and 0.12. There was no significant difference between instruments for crude protein and total fat measurements. There were significant differences in carbohydrate measurements between instruments. For 1 mo of daily measurements in the reliability arm, CVs for filtered mid-IR were ≤4.6%, for Fourier-transformed full spectra mid-IR were ≤1.7%, and for near-IR were ≤5.1%.

CONCLUSIONS

Infrared analysis is an accurate and reliable method for measuring crude protein and total fat in a milk bank setting. Carbohydrate measurements are less accurate and are significantly different between instruments, which will likely lead to differences in derived calorie values.

Bacterial Content of Fortified and Unfortified Holder Pasteurized Donor Human Milk During Prolonged Refrigerated Storage

OBJECTIVE

To assess the microbial growth in unfortified and fortified Holder pasteurized donor human milk (HPDHM) during 96 hours of refrigerated storage in a clinical setting.

METHODS

Thirty-six unfortified samples and 77 fortified samples of HPDHM were prepared in a neonatal intensive care milk preparation room and stored in the NICU refrigerator at 4°C to simulate a real-life feeding environment. One milliliter aliquots were removed at 24-hour intervals and cultured in duplicate for bacterial growth on solid blood agar medium. Viable bacterial colonies were characterized using standard microbiological methods.

RESULTS

96.5% of milk samples manipulated in a vertical laminar flow hood were negative for bacterial growth. In the remainder 3.5% of the samples, the maximum growth was 1 colony forming unit/0.1 ml plated. Higher colony counts were observed when the laminar hood was not used. In all cases, the colonies represented common skin bacteria and demonstrated an inconsistent and unsustained growth. Fortifier status and storage time were not significantly associated with increased bacterial growth (P > 0.05).

CONCLUSIONS

Unfortified and fortified HPDHM remain largely free of bacterial growth for up to 96 hours of refrigerated storage in NICU settings. Sample handling techniques are important for preventing microbial contamination.

Current Trends in Research on Human Milk Exchange for Infant Feeding

Breastfeeding is critical for the healthy growth and development of infants. A diverse range of infant-feeding methods are used around the world today. Many methods involve feeding infants with expressed human milk obtained through human milk exchange. Human milk exchange includes human milk banking, human milk sharing, and markets in which human milk may be purchased or sold by individuals or commercial entities. In this review, we examine peer-reviewed scholarly literature pertaining to human milk exchange in the social sciences and basic human milk sciences. We also examine current position and policy statements for human milk sharing. Our review highlights areas in need of future research. This review is a valuable resource for healthcare professionals and others who provide evidence-based care to families about infant feeding.

Use of Breast Milk and Other Feeding Practices Following Gastrointestinal Surgery in Infants

OBJECTIVES

The aim of the study was to characterize the enteral feeding practices in infants after gastrointestinal surgery.

METHODS

We performed a retrospective analysis of infants who underwent intestinal surgery at age <6 months who survived to be fed enterally between January 2012 and June 2017. Demographics, surgical characteristics, feeding practices, and growth-related outcomes during hospitalization, discharge, and follow-up (3, 6, and 12 months) were obtained from the electronic medical records. Descriptive statistics compared infants by their initial diagnosis.

RESULTS

We reviewed 111 infants: necrotizing enterocolitis (NEC) = 21, gastroschisis = 28, atresia = 27, spontaneous intestinal perforation (SIP) = 18, and other diagnoses = 17. Most infants (77%) received mother's milk (MM) as the first postoperative feed, but this differed by diagnosis (P = 0.004). Donor milk was used in 11%, most commonly in infants with NEC and SIP. Infants with NEC were least likely to continue MM in the hospital (7%, P = 0.0014) and were more likely to receive elemental formula. Only 44% of infants received MM at discharge. After 1 year, 25% were fed MM. The majority of infants were discharged with feeding tubes (nasogastric: 35%, gastric: 23%). Although all groups had acceptable weights at discharge, infants with NEC (z score: -1.8) and SIP (z score: -1.1) showed growth failure at 3 months (z scores: -3.3, -3.2, respectively, P < 0.0001), but had appropriate gain by 1 year (z scores: -1.1, -1.7, respectively).

CONCLUSIONS

Despite most infants receiving MM in the early postoperative period, <50% at discharge and only 33% at 1-year still received MM. Weight gain after discharge in infants with NEC and SIP warrants close monitoring.

Sialylated Oligosaccharides and Glycoconjugates of Human Milk. The Impact on Infant and Newborn Protection, Development and Well-Being

Human milk not only has nutritional value, but also provides a wide range of biologically active molecules, which are adapted to meet the needs of newborns and infants. Mother’s milk is a source of sialylated oligosaccharides and glycans that are attached to proteins and lipids, whose concentrations and composition are unique. Sialylated human milk glycoconjugates and oligosaccharides enrich the newborn immature immune system and are crucial for their proper development and well-being. Some of the milk sialylated oligosaccharide structures can locally exert biologically active effects in the newborn’s and infant’s gut. Sialylated molecules of human milk can be recognized and bound by sialic acid-dependent pathogens and inhibit their adhesion to the epithelial cells of newborns and infants. A small amount of intact sialylated oligosaccharides can be absorbed from the intestine and remain in the newborn’s circulation in concentrations high enough to modulate the immunological system at the cellular level and facilitate proper brain development during infancy. Conclusion: The review summarizes the current state of knowledge on sialylated human milk oligosaccharides and glycoconjugates, discusses the significance of sialylated structures of human milk in newborn protection and development, and presents the advantages of human milk over infant formula.

Going Along With It: Neonatal Intensive Care Nurses' Views of a Donor Milk Practice Change

BACKGROUND AND PURPOSE

Donor human milk (DHM) is used when a mother's own milk is not available. Donor human milk is available as a frozen pasteurized or commercially sterilized product. An abrupt change in practice in use of donor milk products raised concerns among nurses caring for infants in the neonatal intensive care unit (NICU). The change in practice occurred without the input of nurses and without the sharing of supportive evidence with them. The purpose of this study was to explore NICU nurses' perceptions of the practice change from using frozen pasteurized DHM to using sterilized DHM in this context.

STUDY DESIGN AND METHODS

A grounded theory study was conducted in a 38-bed Level III NICU. Nurse participants were interviewed using open-ended questions aimed at eliciting their perceptions of using pasteurized and sterilized DHM.

RESULTS

There were nine nurse participants. They described their perceptions of feeling confident about pasteurized DHM to feeling uncertain about sterilized DHM. The core category of going along with it was linked to judging DHM based upon attributes, questioning benefits of sterilized DHM, and preferring past practice of using pasteurized DHM. Nurses noted that they could move from feeling uncertain about the practice change to feeling certain if they had evidence to support the practice change. Barriers to seeking evidence were time, knowledge, and waiting for someone else to do it.

CLINICAL IMPLICATIONS

Practice change without interprofessional collaboration is threatened by uncertainty and lack of support for the new practice. Nurses want to give evidence-based care, but they often face barriers to seeking evidence. Removing barriers to evidence-based practice and including nurses as stakeholders in practice change decisions are suggested.

Fortification of Human Milk for Preterm Infants: Update and Recommendations of the European Milk Bank Association (EMBA) Working Group on Human Milk Fortification

Evidence indicates that human milk (HM) is the best form of nutrition uniquely suited not only to term but also to preterm infants conferring health benefits in both the short and long-term. However, HM does not provide sufficient nutrition for the very low birth weight (VLBW) infant when fed at the usual feeding volumes leading to slow growth with the risk of neurocognitive impairment and other poor health outcomes such as retinopathy and bronchopulmonary dysplasia. HM should be supplemented (fortified) with the nutrients in short supply, particularly with protein, calcium, and phosphate to meet the high requirements of this group of babies. In this paper the European Milk Bank Association (EMBA) Working Group on HM Fortification discusses the existing evidence in this field, gives an overview of different fortification approaches and definitions, outlines the gaps in knowledge and gives recommendations for practice and suggestions for future research. EMBA recognizes that "Standard Fortification," which is currently the most utilized regimen in neonatal intensive care units, still falls short in supplying sufficient protein for some VLBW infants. EMBA encourages the use of "Individualized Fortification" to optimize nutrient intake. "Adjustable Fortification" and "Targeted Fortification" are 2 methods of individualized fortification. The quality and source of human milk fortifiers constitute another important topic. There is work looking at human milk derived fortifiers, but it is still too early to draw precise conclusions about their use. The pros and cons are discussed in this Commentary in addition to the evidence around use of fortifiers post discharge.

Nutritional Comparison of Raw, Holder Pasteurized, and Shelf-stable Human Milk Products

OBJECTIVE

We aim to assess the nutritional composition of shelf-stable (SS) human milk and compare the nutritional profile to Holder pasteurized (HP) and raw human milk from the same pool.

METHODS

Milk samples from 60 mothers were pooled. From this pool, 36 samples were taken; 12 samples were kept raw, 12 samples were HP, and 12 samples were retort processed to create an SS product. Samples were analyzed for percent fat, percent solids, total protein, lactose, amino acids, and thiamine.

RESULTS

Percent fat, percent solids, and lactose were similar between raw, HP, and SS samples. Total protein was statistically increased in SS samples when compared to raw (P = 0.005) and HP (P < 0.001) samples, but protein differences were not clinically relevant (raw = 15.1 mg/mL, HP = 14.8 mg/mL, and SS = 15.8 mg/mL). Lysine was the only amino acid impacted by processing, and its destruction increased as heat increased (raw = 0.85 mg/100 mL, HP = 0.77 mg/100 mL, SS = 0.68 mg/100 mL). Total thiamine was significantly decreased in SS samples (0.14 mg/L; P < 0.01) when compared with raw samples (0.24 mg/L) and HP samples (0.26 mg/L).

CONCLUSIONS

Macronutrient content is relatively unaffected by processing; Holder pasteurization and retort processing maintain similar fat, lactose, and total protein levels. Lysine and thiamine were significantly decreased by retort processing, but not by Holder pasteurization. Thiamine losses are clinically significant, and fortification may be necessary if SS donor milk is a long-term feeding choice.

Human milk enriched with human milk lyophilisate for feeding very low birth weight preterm infants: A preclinical experimental study focusing on fatty acid profile

BACKGROUND

Human milk, with essential nutrients and long chain polyunsaturated fatty acids (LC-PUFAs) such as the omega 3 and 6 fatty acids is important for development of the central nervous system and the retina in very low birth weight infants (<1,500 g). However, breast milk may not be sufficient to meet these needs. The possibility of supplementing breast milk with a lyophilisate of human milk was explored in this study. The objectives of this study were to determine the total lipid content and the lipid profile of the Human Milk on Baseline (HMB) and that of the Concentrates with the Human Milk + lyophilisate (with lyophilisate of milk in the immediate period (HMCI), at 3 months (HMC3m), and at 6 months (HMC6m) of storage).

METHODS

Fifty donors from the Human Milk Bank of Children's Hospital provided consent, and donated milk samples. Macronutrient (including total lipids) quantification was performed using the MIRIS® Human Milk Analyzer, and the fatty acid profile was determined by gas chromatography (CG-FID, SHIMADZU®).

RESULTS

There was a higher lipid concentration in HMCI relative to HMB. The concentrations of the main fatty acids (% of total) were as follows: palmitic acid (C16:0) HMB, 22.30%; HMCI, 21.46%; HMC3m, 21.54%; and HMC6m, 21.95% (p<0.01); oleic acid (C18:1n-9) HMB, 30.41%; HMCI, 30.47%; HMC3m, 30.55%; and HMC6m, 29.79% (p = 0.46); linoleic acid (C18:2n-6) HMB, 19.62%; HMCI, 19.88%; HMC3m, 19.49%; and HMC6m, 19.45% (p = 0.58); arachidonic acid (C20:4n-6) HMB, 0.35%; HMCI, 0.16%; HMC3m, 0.13%; and HMC6m, 0.15% (p<0.01); α-linolenic acid (C18:3n-3) HMB,1.32%; HMCI, 1.37%; HMC3m, 1.34%; and 1.34% HMC6m (p = 0.14); docosahexaenoic acid (C22:6n-3) HMB, 0.10%; HMCI, 0.06%; HMC3m, 0.05%; and HMC6m, 0.06% (p<0.01). There were no significant changes in the lipid profile when stored. There was no evidence of peroxidation during storage.

CONCLUSIONS

Freeze-dried human milk fortified with a human milk concentrate brings potential benefits to newborns, mainly by preserving the essential nutrients present only in breast milk; however, further clinical studies are required to evaluate the safety and efficacy of the concentrate as a standard nutritional food option for very low birth weight infants.

Human Breast Milk NMR Metabolomic Profile across Specific Geographical Locations and Its Association with the Milk Microbiota

The composition of human breast milk is highly variable, and it can be influenced by genetics, diet, lifestyle, and other environmental factors. This study aimed to investigate the impact of geographical location and mode of delivery on the nuclear magnetic resonance spectroscopy (NMR) metabolic profile of breast milk and its relationship with the milk microbiome. Human milk metabolic and microbiota profiles were determined using NMR and 16S rRNA gene sequencing, respectively, in 79 healthy women from Finland, Spain, South Africa, and China. Up to 68 metabolites, including amino acids, oligosaccharides, and fatty acid-associated metabolites, were identified in the milk NMR spectra. The metabolite profiles showed significant differences between geographical locations, with significant differences (p < 0.05) in the levels of galactose, lacto-N-fucopentaose III, lacto-N-fucopentaose I and 2-fucosyllactose, 3-fucosyllactose, lacto-N-difucohexaose II, lacto-N-fucopentaose III, 2-hydroxybutyrate, 3-hydroxybutyrate, proline, N-acetyl lysine, methyl-histidine, dimethylamine, kynurenine, urea, creatine and creatine phosphate, formate, lactate, acetate, phosphocholine, acetylcholine, LDL, VLDL, ethanolamine, riboflavin, hippurate, spermidine, spermine and uridine. Additionally, the effect of caesarean section on milk metabolome was dependent on the geographical region. Specific interrelations between human milk metabolites and microbiota were also identified. Proteobacteria, Actinobacteria, and Bacilli were most significantly associated with the milk metabolites, being either positively or negatively correlated depending on the metabolite. Our results reveal specific milk metabolomic profiles across geographical locations and also highlight the potential interactions between human milk’s metabolites and microbes.

Donor milk intake and infant growth in a South African neonatal unit: a cohort study

Background

Implications of donor milk feedings on infant growth in resource limited settings remain uncertain. This knowledge gap includes the impact of donor milk availability on infant intake of mother’s own milk. Therefore, this investigation aimed to measure intake and growth in infants receiving donor milk when born to women from resource limited backgrounds with high rates of human immunodeficiency virus (HIV).

Methods

A retrospective cohort study enrolled eligible infants admitted to a South African combined neonatal intensive and secondary high care unit, within a one year admission period during 2015, with signed consent for donor milk feedings. A certified milk bank provided donor milk. Daily nutritional intake during the first month was recorded. Details included proportional intake of donor milk, mother’s own milk and infant formula. The primary outcome of infant growth velocity from day back to birth weight to discharge was calculated when length of stay was ≥14 days. Analyses primarily used T-tests; mixed effects models compared weekly calorie intake.

Results

One hundred five infants with donor milk consent were born at 30.9 ± 3.6 weeks of gestation, weighing 1389 ± 708 g. Forty percent of mothers had HIV. Infant growth velocity did not differ based on percent of feedings as donor milk (≥ 50%: 11.8 ± 4.9 g/kg/d; < 50%: 13.5 ± 5.3 g/kg/d; p = 0.3). Percent of feedings from donor milk was similar based on maternal HIV status (positive: 31 ± 25%; negative: 36 ± 29%; p = 0.4), as was percent of feedings as mother’s milk (positive: 53 ± 35%; negative: 58 ± 30%; p = 0.4). Calorie intake increased markedly during the first two weeks and then plateaued (p < 0.0001).

Conclusions

Donor milk feedings in higher proportions did not further impair growth of infants managed in a South African combined neonatal intensive and secondary high care unit with growth rates already below reference ranges. The provision of donor milk contributed to feedings being composed of primarily human milk during the first month. Increasing early calorie intake may improve infant growth in this center.

Integration of GWAS, pathway and network analyses reveals novel mechanistic insights into the synthesis of milk proteins in dairy cows

The quantities and proportions of protein fractions have notable effects on the nutritional and technological value of milk. Although much is known about the effects of genetic variants on milk proteins, the complex relationships among the set of genes and pathways regulating the different protein fractions synthesis and secretion into milk in dairy cows are still not completely understood. We conducted genome-wide association studies (GWAS) for milk nitrogen fractions in a cohort of 1,011 Brown Swiss cows, which uncovered 170 significant single nucleotide polymorphism (SNPs), mostly located on BTA6 and BTA11. Gene-set analysis and the network-based Associated Weight Matrix approach revealed that the milk proteins associated genes were involved in several biological functions, particularly ion and cation transmembrane transporter activity and neuronal and hormone signalling, according to the structure and function of casein micelles. Deeper analysis of the transcription factors and their predicted target genes within the network revealed that GFI1B, ZNF407 and NR5A1 might act as master regulators of milk protein synthesis and secretion. The information acquired provides novel insight into the regulatory mechanisms controlling milk protein synthesis and secretion in bovine mammary gland and may be useful in breeding programmes aimed at improving milk nutritional and/or technological properties.

Better Control of Holder Pasteurization Results in Higher Retention of Human Milk Lactoferrin, IgA, and Lysozyme

Background: Holder pasteurization is commonly used in milk banks. We previously reported that the pattern of temperature and time may be different according to the pasteurizer used. Aim: The aim of our study was to assess the variances in pasteurization using two different devices: a standard pasteurizer (Past STD) and an optimized pasteurizer (Past OPTI). Methods: Immunoglobulin A (IgA), lactoferrin (LF), and lysozyme (LZ) content were assessed before and after pasteurization of 24 donor human milk samples. The impact of the pasteurization device was evaluated by testing 50- to 200-mL samples. Results: Mean temperature and duration of the plateau were 1.5°C lower and 11 min shorter, respectively, with Past OPTI vs. Past STD. The loss of IgA, LF, and LZ was 17.6, 5.6, and 9.8% lower, respectively, with Past OPTI than with Past STD. Conclusions: Accurate control of temperature enabled better preservation of IgA, LF, and LZ in donor milk. Holder pasteurization should be optimized, and new techniques proposed to treat donor milk should be compared with Holder pasteurization performed with a well-controlled device under realistic conditions.

Bacteria and Bioactivity in Holder Pasteurized and Shelf-Stable Human Milk Products

Background: Historically, Holder pasteurization has been used to pasteurize donor human milk available in a hospital setting. There is extensive research that provides an overview of the impact of Holder pasteurization on bioactive components of human milk. A shelf-stable (SS) human milk product, created using retort processing, recently became available; however, to our knowledge, little has been published about the effect of retort processing on human milk. Objective: We aimed to assess the ability of retort processing to eliminate bacteria and to quantify the difference in lysozyme and secretory immunoglobulin A (sIgA) activity between Holder pasteurized (HP) and SS human milk. Methods: Milk samples from 60 mothers were pooled. From this pool, 36 samples were taken: 12 samples were kept raw, 12 samples were HP, and 12 samples were retort processed to create an SS product. All samples were analyzed for total aerobic bacteria, coliform bacteria, Bacillus cereus, sIgA activity, and lysozyme activity. Raw samples served as the control. Results: One raw sample and 3 HP samples contained B. cereus at the time of culture. There were no detectable bacteria in SS samples at the time of culture. Raw samples had significantly greater lysozyme and sIgA activity than HP and SS samples (P < 0.0001). HP samples retained significantly more lysozyme and sIgA activity (54% and 87%, respectively) than SS samples (0% and 11%, respectively). Conclusions: Human milk processed using Holder pasteurization should continue to be screened for the presence of B. cereus. Clinicians should be aware of the differences in the retention of lysozyme and sIgA activity in HP and SS products when making feeding decisions for medically fragile or immunocompromised infants to ensure that patients are receiving the maximum immune protection.