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

Donor human milk: the influence of processing technologies on its nutritional and microbial composition

Human milk is regarded as the gold standard nutrition for newborn infants, providing all nutrients required for adequate growth and development from birth to 6 months. In addition, human milk is host to an array of bioactive factors that confer immune protection to the newborn infant. For this reason, the supply of human milk is crucial for premature, seriously ill, or low birth weight infants (<1,500 g). When a mother's own milk is unavailable, donor human milk is the recommended alternative by the World Health Organization. Prior to consumption, donor human milk undergoes pasteurization to ensure the eradication of bacterial agents and prevent the transfer of potentially pathogenic organisms. Currently, Holder Pasteurization, a heat-based treatment, is the widely adopted pasteurization technique used by milk banks. Holder pasteurization has demonstrated degradative effects on some of milk's biologically active factors, thus depleting critical bioactive agents with known functional, protective, and beneficial properties, ultimately reducing the immunoprotective value of donor human milk. As a result, alternative strategies for the processing of donor human milk have garnered much interest. These include thermal and non-thermal techniques. In the current review, we describe the effects of Holder pasteurization and alternative milk processing technologies on the nutritional and bioactive properties of milk. In addition, the capacity of each technique to ensure microbial inactivation of milk is summarized. These include the most extensively studied, high-temperature short-time and high-pressure processing, the emerging yet promising techniques, microwave heating and UV-C irradiation, and the lesser studied technologies, thermoultrasonication, retort processing, pulsed electric field, and gamma irradiation. Herein, we collate the findings of studies, to date, to allow for greater insight into the existing gaps in scientific knowledge. It is apparent that the lack of a cohesive standardized approach to human milk processing has resulted in contrasting findings, preventing a direct comparative analysis of the research. We conclude that donor human milk is a unique and valuable resource to the health sector, and although substantial research has been completed, persistent data disparities must be overcome to ensure optimal nutrition for the vulnerable newborn preterm infant group, in particular.

Early human milk feeding: Relationship to intestinal barrier maturation and postnatal growth

OBJECTIVES

Early exposure to mother's own milk (MOM) promotes intestinal barrier maturation in preterm infants. We hypothesized (1) donor human milk (DHM) supplementation reduces intestinal permeability (IP) similar to exclusive MOM and (2) early HM exposure and low IP at 7-10 days postnatal age (PNA) are associated with improved growth outcomes.

METHODS

IP was measured by the standard sugar absorption test (SAT) in infants <33 weeks gestation between 7-10 days PNA. Nutritional and anthropometric data were recorded. Postnatal growth failure (PNGF) was defined as a decrease in weight z-score >1 from birth to discharge to home.

RESULTS

Of 158 preterm infants, the mean (SD) gestational age was 29.9(2.3) weeks and birthweight 1388(424) g. Diet prior to SAT was exclusive MOM [N = 55(35%)], DHM ± MOM [N = 52(33%)], or preterm formula±MOM [N = 51(32%)]. The mean Lactulose(La)/Rhamnose(Rh) ratio was lower in the exclusive MOM [0.06(0.07)] and DBM ± MOM [0.05(0.07)] groups compared to the preterm formula±MOM group [0.11(0.11)], p < 0.01). Cumulative intake >150 ml/kg MOM ± DHM, but not preterm formula within 7-10 days PNA was associated with early intestinal barrier maturation. Low IP was not associated with lower risk of PNGF at discharge.

CONCLUSIONS

Low IP is associated with cumulative intake of MOM alone or supplemented with DHM > 150 ml/kg within 7-10 days PNA.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT01756040 ; web link to study on registry: https://clinicaltrials.gov/study/NCT01756040 .

IMPACT

Key message Early intestinal barrier maturation is associated with cumulative intake of exclusive MOM alone or supplemented with DHM > 150 ml/kg within 7-10 days after birth, but is not associated with lower risk of PNGF at time of discharge. What it adds to existing literature? This observational study is the first study to demonstrate that supplemental DHM promotes intestinal barrier maturation similar to MOM alone. What is the impact? The findings underscore the importance of early introduction of human milk feeds as MOM or MOM supplemented with DHM in sufficient volume to promote early intestinal barrier maturation.

Donor human milk for preventing necrotising enterocolitis in very preterm or very low-birthweight infants

BACKGROUND

When sufficient maternal milk is not available, donor human milk or formula are the alternative forms of enteral nutrition for very preterm or very low-birthweight (VLBW) infants. Donor human milk may retain the non-nutritive benefits of maternal milk and has been proposed as a strategy to reduce the risk of necrotising enterocolitis (NEC) and associated mortality and morbidity in very preterm or VLBW infants.

OBJECTIVES

To assess the effectiveness of donor human milk compared with formula for preventing NEC and associated morbidity and mortality in very preterm or VLBW infants when sufficient maternal milk is not available.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Maternity and Infant Care (MIC) database, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), from the earliest records to February 2024. We searched clinical trials registries and examined the reference lists of included studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing feeding with donor human milk versus formula in very preterm (< 32 weeks' gestation) or VLBW (< 1500 g) infants.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated the risk of bias in the trials, extracted data, and synthesised effect estimates using risk ratio, risk difference, and mean difference, with associated 95% confidence intervals. The primary outcomes were NEC, late-onset invasive infection, and all-cause mortality before hospital discharge. The secondary outcomes were growth parameters and neurodevelopment. We used the GRADE approach to assess the certainty of the evidence for our primary outcomes.

MAIN RESULTS

Twelve trials with a total of 2296 infants fulfilled the inclusion criteria. Most trials were small (average sample size was 191 infants). All trials were performed in neonatal units in Europe or North America. Five trials were conducted more than 40 years ago; the remaining seven trials were conducted in the year 2000 or later. Some trials had methodological weaknesses, including concerns regarding masking of investigators and selective reporting. Meta-analysis showed that donor human milk reduces the risk of NEC (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.37 to 0.76; I² = 4%; risk difference (RD) -0.03, 95% CI -0.05 to -0.01; 11 trials, 2261 infants; high certainty evidence). Donor human milk probably has little or no effect on late-onset invasive infection (RR 1.12, 0.95 to 1.31; I² = 27%; RD 0.03, 95% CI -0.01 to -0.07; 7 trials, 1611 infants; moderate certainty evidence) or all-cause mortality (RR 1.00, 95% CI 0.76 to 1.31; I² = 0%; RD -0.00, 95% CI -0.02 to 0.02; 9 trials, 2116 infants; moderate certainty evidence).

AUTHORS' CONCLUSIONS

The evidence shows that donor human milk reduces the risk of NEC by about half in very preterm or VLBW infants. There is probably little or no effect on late-onset invasive infection or all-cause mortality before hospital discharge.

Deciphering macronutrient information about human milk

Clinicians caring for small, vulnerable newborns increasingly have access to specific nutritional information about human milk through point-of-care analyzers and labeled products. It is critical for clinicians to recognize that there is considerable variability in how human milk nutritional data are derived and reported, which impacts the interpretation of nutritional values, comparison of nutritional data between products, and ultimately the ability to deliver optimal nutritional care. This article distills key issues that will enable clinicians to interpret human milk nutritional labels/analysis more effectively, ultimately allowing them to make better decisions about dietary strategies. We aim to empower clinicians to ask questions about milk sampling techniques, reported nutrient values, analysis techniques, and milk bank pooling practices. This knowledge can put human milk nutrient values in context, improve clinical care, and help to drive more rigorous research for exploring the impact of human milk feeding on infant outcomes.

The impact of storage, handling, and treatment on nutritional quality and safety of animal milk: A protocol for the systematic review and meta-analysis

Objectives

Human milk has been shown to reduce severe morbidity in preterm/low-birth-weight infants and is therefore the recommended nutritional source. When infants cannot receive maternal milk, donor human milk (DHM) is recommended. The use of human milk banking facilities is increasing to meet the need for DHM. DHM is unique compared to maternal milk as it must be processed and stored. The processing and storage of animal milk has been more rigorously studied than human milk and can serve as proxy to create DHM banking guidelines.

Methods and Analysis

We will search electronic databases, grey literature, and the websites of relevant international organizations. We will include studies that evaluated the impact of storage, handling, and treatment on the nutritional quality and safety of animal milk. We will not restrict study date, language, or design. If sufficient homogeneity exists between studies, we will conduct a meta-analysis. We will evaluate the methodological quality of each study using the SYRCLE's (Systematic Review Centre for Laboratory Animal Experimentation) risk of bias tool. (1) We will evaluate the overall certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

Conclusion

In this systematic review and meta-analysis, commissioned by the World Health Organization, we will synthesize the available literature regarding the impact of various storage, handling, and treatment practices on the nutritional quality and safety of animal milk.

Human Milk-The Biofluid That Nourishes Infants from the First Day of Life

Human milk is a biofluid with a unique composition among mammalian milks. Besides this milk's major components, its bioactive compounds, like hormones, immune factors, and oligosaccharides, are unique and important for infant growth and development. The best form of nutrition for term and preterm infants is the mother's own milk. However, in the absence of the mother's own milk, donor milk should be made available. Milk banks support neonatal intensive care units by providing preterm infants with human milk that generally has reasonable nutritive value for this sensitive population. However, neither mother's own milk nor donor milk has sufficient energy content for the growth of preterm babies, so adequate human milk supplementation is crucial for their progress. Due to the different characteristics of human breast milk, as well as ubiquitous environmental pollutants, such as microplastics, new methods are required for monitoring the quality and characteristics of human milk, which will lay a solid foundation for the further development and progress of human milk research.

Neurodevelopmental Outcomes of Extremely Preterm Infants Fed Donor Milk or Preterm Infant Formula: A Randomized Clinical Trial

Importance

Maternal milk feeding of extremely preterm infants during the birth hospitalization has been associated with better neurodevelopmental outcomes compared with preterm formula. For infants receiving no or minimal maternal milk, it is unknown whether donor human milk conveys similar neurodevelopmental advantages vs preterm formula.

Objective

To determine if nutrient-fortified, pasteurized donor human milk improves neurodevelopmental outcomes at 22 to 26 months' corrected age compared with preterm infant formula among extremely preterm infants who received minimal maternal milk.

Design, Setting, and Participants

Double-blind, randomized clinical trial conducted at 15 US academic medical centers within the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants younger than 29 weeks 0 days' gestation or with a birth weight of less than 1000 g were enrolled between September 2012 and March 2019.

Intervention

Preterm formula or donor human milk feeding from randomization to 120 days of age, death, or hospital discharge.

Main Outcomes and Measures

The primary outcome was the Bayley Scales of Infant and Toddler Development (BSID) cognitive score measured at 22 to 26 months' corrected age; a score of 54 (score range, 54-155; a score of ≥85 indicates no neurodevelopmental delay) was assigned to infants who died between randomization and 22 to 26 months' corrected age. The 24 secondary outcomes included BSID language and motor scores, in-hospital growth, necrotizing enterocolitis, and death.

Results

Of 1965 eligible infants, 483 were randomized (239 in the donor milk group and 244 in the preterm formula group); the median gestational age was 26 weeks (IQR, 25-27 weeks), the median birth weight was 840 g (IQR, 676-986 g), and 52% were female. The birthing parent's race was self-reported as Black for 52% (247/478), White for 43% (206/478), and other for 5% (25/478). There were 54 infants who died prior to follow-up; 88% (376/429) of survivors were assessed at 22 to 26 months' corrected age. The adjusted mean BSID cognitive score was 80.7 (SD, 17.4) for the donor milk group vs 81.1 (SD, 16.7) for the preterm formula group (adjusted mean difference, -0.77 [95% CI, -3.93 to 2.39], which was not significant); the adjusted mean BSID language and motor scores also did not differ. Mortality (death prior to follow-up) was 13% (29/231) in the donor milk group vs 11% (25/233) in the preterm formula group (adjusted risk difference, -1% [95% CI, -4% to 2%]). Necrotizing enterocolitis occurred in 4.2% of infants (10/239) in the donor milk group vs 9.0% of infants (22/244) in the preterm formula group (adjusted risk difference, -5% [95% CI, -9% to -2%]). Weight gain was slower in the donor milk group (22.3 g/kg/d [95% CI, 21.3 to 23.3 g/kg/d]) compared with the preterm formula group (24.6 g/kg/d [95% CI, 23.6 to 25.6 g/kg/d]).

Conclusions and Relevance

Among extremely preterm neonates fed minimal maternal milk, neurodevelopmental outcomes at 22 to 26 months' corrected age did not differ between infants fed donor milk or preterm formula.

Trial Registration

ClinicalTrials.gov Identifier: NCT01534481.

Protective Characteristics of Human Breast Milk on Early Childhood Otitis Media: A Narrative Review

Introduction: Human breast milk (HBM) contains a complex and dynamically changing variety of factors that contribute to the infant's developing immune system's ability to fight upper respiratory tract infections, including otitis media (OM). We sought to summarize the current evidence on the protective characteristics of HBM, through direct or donated feeding, toward early childhood OM. Methods: For this narrative review, we performed a literature search on OM in the context of HBM feeding in the PubMed, Embase, and Google Scholar databases, between January 1, 2008, and July 1, 2023. Results: Immunoglobulin A (IgA) provides a short-term immunity of 2-3 days against otopathogens causing OM. IgA-mediated immunity is effective against OM up to 7 months of age if breastfeeding continues. The role of transferred IgM and IgG in HBM is unclear. Although there is a potential protective value of microRNA, hormones, oligosaccharides, stem cells, and interleukins present in HBM, their role is unclear. Any duration of breastfeeding is superior to no breastfeeding in OM risk reduction, with a big variability among studies (odds ratio 0.23-0.81, depending on the duration). Duration of breastfeeding ≥6 months was found to be the most effective in OM risk reduction, but there was no evidence of continued benefits after 2 years of age. Expressed breastfeeding was not shown to be more beneficial. The protective values of donor HBM against OM are still undetermined. Conclusion: HBM has numerous components that contribute to protection against early childhood OM.

Importance of human milk for infants in the clinical setting: Updates and mechanistic links

INTRODUCTION

Human milk (HM) is the optimal source of nutrition for infants and has been implicated in multiple aspects of infant health. Although much of the existing literature has focused on the individual components that drive its nutrition content, examining HM as a biological system is needed for meaningful advancement of the field. Investigation of the nonnutritive bioactive components of HM and the maternal, infant, and environmental factors which affect these bioactives is important to better understand the importance of HM provision to infants. This information may inform care of clinical populations or infants who are critically ill, hospitalized, or who have chronic diseases and may benefit most from receiving HM.

METHODS

In this narrative review, we reviewed literature examining maternal and infant influences on HM composition with a focus on studies published in the last 10 years that were applicable to clinical populations.

RESULTS

We found multiple studies examining HM components implicated in infant immune and gut health and neurodevelopment. Additional work is needed to understand how donor milk and formula may be used in situations of inadequate maternal HM. Furthermore, a better understanding of how maternal factors such as maternal genetics and metabolic health influence milk composition is needed.

CONCLUSION

In this review, we affirm the importance of HM for all infants, especially clinical populations. An understanding of how HM composition is modulated by maternal and environmental factors is important to progress the field forward with respect to mechanistic links between HM biology and infant health outcomes.

Human Milk Fortification Strategies in the Neonatal Intensive Care Unit

Multicomponent fortification is the standard of care to support short-term growth in preterm infants receiving human milk. There is no consensus regarding the optimal timing, method, or products used to fortify human milk. Both bovine milk-based and human milk-based human milk fortifiers are safe options, though increased fortification and enrichment may be needed to achieve adequate growth. Additional studies are needed to evaluate newer fortifier products and fortification strategies.

The role of human milk nutrients in preventing necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an intestinal disease that primarily impacts preterm infants. The pathophysiology of NEC involves a complex interplay of factors that result in a deleterious immune response, injury to the intestinal mucosa, and in its most severe form, irreversible intestinal necrosis. Treatments for NEC remain limited, but one of the most effective preventative strategies for NEC is the provision of breast milk feeds. In this review, we discuss mechanisms by which bioactive nutrients in breast milk impact neonatal intestinal physiology and the development of NEC. We also review experimental models of NEC that have been used to study the role of breast milk components in disease pathophysiology. These models are necessary to accelerate mechanistic research and improve outcomes for neonates with NEC.

Key biologically active components of breast milk and their beneficial effects

Maternal breast milk is the penultimate nutritional source for term and preterm neonates. Its composition is highly complex and includes multiple factors that enhance the development of nearly every neonatal organ system leading to both short- and long-term health benefits. Intensive research is focused on identifying breast milk components that enhance infant health. However, this research is complicated by the significant impact of maternal factors and the processing of pumped breast milk on bioactive ingredients. Optimizing enteral nutrition is particularly important for preterm neonates who miss the transplacental acquisition of nutrients in the third trimester of pregnancy and are at risk for illnesses associated with gut barrier dysfunction, including sepsis and necrotizing enterocolitis. In this review, we will discuss the health benefits of breast milk and its bioactive components.

[Effect of pasteurization and freezing on the content of IgA1 and IgA2 subtypes in breast milk]

OBJECTIVE

To determine the effect of pasteurization and freezing on the content of IgA1 and IgA2 in breast milk.

METHODS

Observational, retrospective study, carried out in women who had been breastfeeding their newborn for more than 30 days, and could donate 50 mL of milk. The concentration of IgA1 and IgA2 was determined by turbidimetry, before and after being subjected to pasteurization and freezing, every 15 days for 2 months. Freezing was at -20°C. A total IgA content of 1598.5 mg/dL was found.

RESULTS

10 breast milk donors were selected. The initial concentration of IgA1 and IA2 was 651 and 945.7 mg/dL, respectively; At the end of the freezing times, the content of both immunoglobulins decreased: IgA1 of 74% and IgA2 of 86%. After the treatments, the immunoglobulin content decreased dramatically, with a significant difference of p < 0.05.

CONCLUSIONS

Pasteurization and freezing significantly affect the content of IgA1 and IgA in breast milk; therefore, breast-feeding remains the best way to offer full immunological protection to the infant.

Pooling Strategies to Modify Macronutrient Content of Pasteurized Donor Human Milk

Background: Donor human milk (DHM) is the recommended feeding for preterm infants when mother's own milk is unavailable or insufficient. DHM macronutrient's variability may have significant implications on preterm growth. Different pooling strategies could be used to improve the macronutrient content, facilitating the achievement of nutritional requirements of preterm. Objective: The aim was to compare the impact of random pooling (RP) and target pooling (TP) strategies on the macronutrient content of DHM and to identify which RP practice allows the achievement of a macronutrient composition as similar as possible to that achievable with TP. Methods: The macronutrient content of 1,169 single-donor pools was analyzed, and a TP strategy combining 2,3,4, or 5 single-donor pools was adopted. On the bases of single-donor pools' analyses, a simulation of 10,000 randomly selected pools for each configuration of donor considered and for different milk volume proportions was performed. Results: Regardless of the type of strategy and milk volume, as the number of donor per pool increases, the percentage of pools with a macronutrient content equal or higher than the reference values for human milk increases. Conclusion: When a TP strategy is not feasible, a RP strategy combining at least five donors should be performed to obtain a better macronutrient content of DHM.

Necrotizing enterocolitis in premature infants-A defect in the brakes? Evidence from clinical and animal studies

A key aspect of postnatal intestinal adaptation is the establishment of symbiotic relationships with co-evolved gut microbiota. Necrotizing enterocolitis (NEC) is the most severe disease arising from failure in postnatal gut adaptation in premature infants. Although pathological activation of intestinal Toll-like receptors (TLRs) is believed to underpin NEC pathogenesis, the mechanisms are incompletely understood. We postulate that unregulated aberrant TLR activation in NEC arises from a failure in intestinal-specific mechanisms that tamponade TLR signaling (the brakes). In this review, we discussed the human and animal studies that elucidate the developmental mechanisms inhibiting TLR signaling in the postnatal intestine (establishing the brakes). We then evaluate evidence from preclinical models and human studies that point to a defect in the inhibition of TLR signaling underlying NEC. Finally, we provided a framework for the assessment of NEC risk by screening for signatures of TLR signaling and for NEC prevention by TLR-targeted therapy in premature infants.

Solvent-Free Lipid Separation and Attenuated Total Reflectance Infrared Spectroscopy for Fast and Green Fatty Acid Profiling of Human Milk

This study presents the first mid-infrared (IR)-based method capable of simultaneously predicting concentrations of individual fatty acids (FAs) and relevant sum parameters in human milk (HM). Representative fat fractions of 50 HM samples were obtained by rapid, two-step centrifugation and subsequently measured with attenuated total reflection IR spectroscopy. Partial least squares models were compiled for the acquired IR spectra with gas chromatography-mass spectrometry (GC-MS) reference data. External validation showed good results particularly for the most important FA sum parameters and the following individual FAs: C12:0 (R²_P = 0.96), C16:0 (R²_P = 0.88), C18:1cis (R²_P = 0.92), and C18:2cis (R²_P = 0.92). Based on the obtained results, the effect of different clinical parameters on the HM FA profile was investigated, indicating a change of certain sum parameters over the course of lactation. Finally, assessment of the method's greenness revealed clear superiority compared to GC-MS methods. The reported method thus represents a high-throughput, green alternative to resource-intensive established techniques.

Biomonitoring bisphenols, parabens, and benzophenones in breast milk from a human milk bank in Southern Spain

BACKGROUND

Human breast milk is considered the optimal source of nutrition for infants. Milk from breast milk banks offers an alternative to infant formulas for vulnerable hospitalized neonates most likely to benefit from exclusive human milk feeding. However, breast milk can also be a source of exposure to environmental contaminants, including endocrine-disrupting chemicals (EDCs).

AIM

To evaluate concentrations of phenolic EDCs, including bisphenols, parabens (PBs), and benzophenones (BPs), in samples from a human milk bank in Granada, Southern Spain and to explore sociodemographic, reproductive, and lifestyle factors related to their concentrations in the milk.

METHODS

Concentrations of three bisphenols [bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS)], four PBs [methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP)], and six BPs [BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP] were determined in milk samples from 83 donors. Information on potential explanatory variables was gathered using the milk bank donor form and an ad hoc questionnaire. Multiple linear and logistic regression models were fitted.

RESULTS

Detectable concentrations were found of at least one of the analyzed compounds in all donor breast milk samples and at least five compounds in one-fifth of them. The most frequently detected compounds were MeP (90.5%), BP-3 (75.0%), EtP (51.2%), n-PrP (46.4%), and BPA (41.7%). Median concentrations ranged between <0.10 ng/mL (n-PrP, n-BuP, BP-1) and 0.59 ng/mL (BP-3). No sample contained detectable concentrations of BPF, BPS, or most BPs (BP-2, BP-6, BP-8, and 4- hydroxy-BP). Breast milk phenol concentrations were associated with parity, the utilization of deodorants, mouthwash, skin care products, and cosmetics, and the intake of nutritional supplements.

CONCLUSIONS

Results reveal the widespread presence of BPA, PBs, and BP-3 in donor breast milk samples, highlighting the need for preventive measures to enhance the benefits of breast milk from milk banks and from breastfeeding women in general.

A Pilot Study on Donor Human Milk Microbiota: A Comparison with Preterm Human Milk Microbiota and the Effect of Pasteurization

Human milk (HM) is the best feeding option for preterm infants; however, when mother’s own milk (MOM) is not available, pasteurized donor human milk (DHM) is the best alternative. In this study, we profiled DHM microbiota (19 samples) using 16S rRNA amplicon sequencing and compared its compositional features with the MOM microbiota (14 samples) from mothers who delivered prematurely (PT-MOM). As a secondary study aim, we assessed the specific effect of pasteurization on the characteristics of the DHM microbiota. DHM showed significantly higher alpha diversity and significant segregation from PT-MOM. Compositionally, the PT-MOM microbiota had a significantly higher proportion of Staphylococcus than DHM, with Streptococcus tending to be and Pseudomonas being significantly overrepresented in DHM compared with the PT-MOM samples. Furthermore, pasteurization affected the HM microbiota structure, with a trend towards greater biodiversity and some compositional differences following pasteurization. This pilot study provided further evidence on the HM microbial ecosystem, demonstrating that the DHM microbiota differs from the PT-MOM microbiota, possibly due to inherent differences between HM donors and mothers delivering prematurely, and that pasteurization per se impacts the HM microbiota. Knowledge about HM microbiota needs to be acquired by investigating the effect of DHM processing to develop strategies aimed at improving DHM quality while guaranteeing its microbiological safety.

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.

Human Milk and Preterm Infant Brain Development: A Narrative Review

PURPOSE

To review and synthesize the literature on human milk and structural brain development and injury in preterm infants, focusing on the application of quantitative brain magnetic resonance imaging (MRI) in this field.

METHODS

For this narrative review, we searched PubMed for articles published from 1990 to 2021 that reported observational or interventional studies of maternal milk or donor milk in relation to brain development and/or injury in preterm infants assessed with quantitative MRI at term equivalent age. Studies were characterized with respect to key aspects of study design, milk exposure definition, and MRI outcomes.

FINDINGS

We identified 7 relevant studies, all of which were observational in design and published between 2013 and 2021. Included preterm infants were born at or below 33 weeks' gestation. Sample sizes ranged from 22 to 377 infants. Exposure to human milk included both maternal and donor milk. No study included a full-term comparison group. Main MRI outcome domains were white matter integrity (assessed with diffusion tensor imaging, resting state functional connectivity, or semiautomated segmentation of white matter abnormality) and total and regional brain volumes. Studies revealed that greater exposure to human milk versus formula was associated with favorable outcomes, including more mature and connected cerebral white matter with less injury and larger regional brain volumes, notably in the deep nuclear gray matter, amygdala-hippocampus, and cerebellum. No consistent signature effect of human milk exposure was found; instead, the beneficial associations were regional and tissue-specific neuroprotective effects on the areas of known vulnerability in the preterm infant.

IMPLICATIONS

Evidence to date suggests that human milk may protect the preterm infant from the white matter injury and dysmaturation to which this population is vulnerable. Brain MRI at term equivalent age is emerging as a useful tool to investigate the effects of human milk on the preterm brain. When grounded in neurobiological knowledge about preterm brain injury and development, this approach holds promise for allowing further insight into the mechanisms and pathways underlying beneficial associations of human milk with neurodevelopmental outcomes in this population and in the investigation of specific milk bioactive components with neuroprotective or neurorestorative potential.

Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is considered to be one of the most devastating intestinal diseases seen in neonatal intensive care. Measures to treat NEC are often too late, and we need effective preventative measures to alleviate the burden of this disease. The purpose of this review is to summarize currently used measures, and those showing future promise for prevention.

Mother's Own Milk and Its Relationship to Growth and Morbidity in a Population-based Cohort of Extremely Preterm Infants

OBJECTIVES

The aim of the study was to evaluate the relationships between intake of mother's own milk (MOM), compared with intake of pasteurized donor milk (DM), and postnatal growth, incidence of retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD), in extremely preterm infants.

METHODS

Swedish population-based cohort of surviving extremely preterm infants born 2004 to 2007. Exposure to MOM and DM was investigated from birth until 32 weeks postmenstrual age (PMA) in 453 infants. Primary outcome variables were change in z-score (Δ) from birth to 32 weeks PMA for weight, length, and head circumference (HC). Secondary outcomes were incidence of ROP and BPD. Mixed models adjusting for confounders were used to investigate the association between exposures and outcomes.

RESULTS

Infants' mean gestational age (GA) was 25.4 weeks. Unadjusted, MOM (per 10 mL · kg-1 · day-1) was associated with Δweight and ΔHC with beta estimates of 0.03 z-score units (95% CI, 0.02-0.04, P < 0.001) and 0.03 z-score units (95% CI, 0.01-0.05, P = 0.003), respectively. After adjustment for predefined confounders, the association remained significant for Δweight and ΔHC. A similar pattern was found between Δweight and each 10% increase of MOM. Unadjusted, a higher intake of MOM (mL · kg-1 · day-1) was significantly associated to a lower probability of any ROP and severe ROP; however, these associations did not remain in the adjusted analyses. No associations were found between MOM (mL · kg-1 · day-1) and BPD. Moreover, no associations were found between DM and growth or morbidity outcomes.

CONCLUSIONS

An increased intake of MOM, as opposed to DM (and not formula feeding), was associated with improved postnatal weight gain and HC growth from birth until 32 weeks PMA in extremely preterm infants. Interventions aiming at increasing early intake of unpasteurized MOM for extremely preterm infants should be encouraged.

Real-time monitoring of immunoglobulin G levels in milk using an ordered porous layer interferometric optical sensor

Immunoglobulin G (IgG) is a significant ingredient of immunological activity in milk and colostrum, the activity and content of which is easily disturbed by potentially conditional variant during sterilization. Therefore, developing robust methods for the detection of IgG levels in milk is especially important. Herein, protein A from the Staphylococcus aureus functionalized silica colloidal crystalline film (SCC@SPA) sensing unit combined with ordered porous layer interferometry (OPLI) for IgG detection in untreated bovine milk was developed. Calibration curves in milk and buffer were set up by the variations of the optical thickness (OT) of the sensing unit after the IgG association and dissociation phases. The influence of temperature on the level of IgG was evaluated. Furthermore, the identification of IgG levels with pasteurized milk and ultrahigh temperature (UHT) sterilized milk from the market randomly was successfully carried out without any sample pretreatment. More importantly, compared with other methods, this novel method has the advantages of convenient operation, low cost, and suitability for point-of-care (POC) testing.

The Current State of Donor Human Milk Use and Practice

Human milk contains nutrients and immune factors that promote health and growth of an infant. Donor human milk is recommended as the best alternative for infants whose mothers' breast milk is unavailable. This article describes the current status of donor human milk practice and suggests the areas of educational and research needs. Articles published in the last 10 years were reviewed, and findings were summarized under 4 themes: (1) women's knowledge and concerns about donor human milk use, (2) hospital practices, (3) cost-effectiveness, and (4) access and affordability of donor human milk. Women were concerned about donor human milk contamination, disease transmission, cost, and access to bank donor human milk, due to lack of knowledge and awareness of donor human milk benefits and its processing procedures. The absence of health care providers' support for donor human milk adds to the confusion. There is a rising trend of donor human milk use in hospitals for both healthy and vulnerable newborns and infants with varying policies on screening for donor human milk use, cost coverage, or consent procedure. However, a shortage of safe and affordable donor human milk is a barrier to its adoption. A standardized guideline is needed for hospitals regarding donor human milk implementation and cost coverage. Education programs for health care providers are needed to improve knowledge and understanding of donor human milk benefits and safety to provide guidance to parents. It is crucial to develop legislation expanding insurance coverage to achieve donor human milk equity and optimizing long-term human milk diet outcomes.