Review shows that donor milk does not promote the growth and development of preterm infants as well as maternal milk

Milk microbiome transplantation: recolonizing donor milk with mother's own milk microbiota

Donor human milk (DHM) provides myriad nutritional and immunological benefits for preterm and low birthweight infants. However, pasteurization leaves DHM devoid of potentially beneficial milk microbiota. In the present study, we performed milk microbiome transplantation from freshly collected mother's own milk (MOM) into pasteurized DHM. Small volumes of MOM (5%, 10%, or 30% v/v) were inoculated into pasteurized DHM and incubated at 37 °C for up to 8 h. Further, we compared microbiome recolonization in UV-C-treated and Holder-pasteurized DHM, as UV-C treatment has been shown to conserve important biochemical components of DHM that are lost during Holder pasteurization. Bacterial culture and viability-coupled metataxonomic sequencing were employed to assess the effectiveness of milk microbiome transplantation. Growth of transplanted MOM bacteria occurred rapidly in recolonized DHM samples; however, a greater level of growth was observed in Holder-pasteurized DHM compared to UV-C-treated DHM, potentially due to the conserved antimicrobial properties in UV-C-treated DHM. Viability-coupled metataxonomic analysis demonstrated similarity between recolonized DHM samples and fresh MOM samples, suggesting that the milk microbiome can be successfully transplanted into pasteurized DHM. These results highlight the potential of MOM microbiota transplantation to restore the microbial composition of UV-C-treated and Holder-pasteurized DHM and enhance the nutritional and immunological benefits of DHM for preterm and vulnerable infants. KEY POINTS: • Mother's own milk microbiome can be successfully transplanted into donor human milk. • Recolonization is equally successful in UV-C-treated and Holder-pasteurized milk. • Recolonization time should be restricted due to rapid bacterial growth.

A Systemic Review of the Difference Between Diets for Preterm Infants Containing Raw Mother's Own Milk and Frozen or Pasteurized Mother's Own Milk

BACKGROUND

Raw, never stored or pasteurized mother's own milk (MOM) is not always available to feed preterm infants; however, storage and pasteurization of MOM diminishes some bioactive components. It can be difficult to feed raw MOM to preterm infants due to transportation and storage of small volumes that might be pumped away from the infant, and a concern that they might harbor bacteria. However, the higher availability of bioactive components in raw MOM may provide benefits to preterm infants compared to frozen or pasteurized MOM.

RESEARCH AIM

To systematically review and summarize the results of studies on feeding raw MOM versus frozen or pasteurized MOM to preterm infants born at less than 37 weeks of gestation.

METHODS

Four databases were searched (Cochrane, Embase, Ovid MEDLINE, and Web of Science) for this systematic review. Of 542 studies identified, nine met inclusion criteria and were critically evaluated using the quality assessment tool for quantitative studies by the Effective Public Health Practice Project. Studies were organized using the Breastfeeding Challenges Facing Preterm Mother-Infant Dyads theoretical framework.

RESULTS

Included studies evaluated the outcomes of preterm infants fed raw versus pasteurized MOM (n = 7, 77.8%) or raw versus frozen MOM (n = 2, 22.2%). Researchers found that raw MOM did not increase infant infections and may have improved health and growth outcomes for study participants.

CONCLUSION

There is laboratory evidence supporting the safety and efficacy of the use of raw MOM for preterm infants. A raw MOM diet is recommended for preterm infants by professional organizations. Despite this, it may not be universally prioritized and could require purposeful implementation by each institution. Further research is needed to pursue the potential benefits of a raw MOM diet for preterm infants.

The Effect of Holder Pasteurization and Different Variants on Breast Milk Antioxidants

BACKGROUND

After birth, breast milk (BM) is a known essential source of antioxidants for infants. We analyzed the non-enzymatic total antioxidant capacity (TAC), oxygen radical absorbance capacity (ORAC), and glutathione, calcium, transferrin, and total protein levels of human breast milk before and after Holder pasteurization (HoP).

METHODS

The collected donor BM samples were pasteurized with HoP.

RESULTS

HoP decreased TAC (-12.6%), ORAC (-12.1%), transferrin (-98.3%), and total protein (-21.4%) levels; HoP did not influence the glutathione concentration, and it increased the total calcium (+25.5%) concentration. Mothers who gave birth via Cesarean section had significantly lower TAC in their BM. TAC and glutathione levels were elevated in the BM of mothers over the age of 30. BM produced in the summer had higher glutathione and calcium levels compared to BM produced in the winter. The glutathione concentration in term milk samples was significantly higher in the first two months of lactation compared to the period between the third and sixth months. The transferrin level of BM for female infants was significantly higher than the BM for boys, and mothers with a BMI above 30 had increased transferrin in their samples.

CONCLUSIONS

Antioxidant levels in human milk are influenced by numerous factors. Environmental and maternal factors, the postpartum age at breast milk collection, and Holder pasteurization of the milk influence the antioxidant intake of the infant.

Lipid Peroxidation and Antioxidative Capacity Are Unaltered in Transitional Breast Milk Exposed to Light from Women Giving Birth to Preterm Infants before 32 Weeks of Gestation

Breast milk (BM) is the primary nutrition for infants and has a high content of lipids. Preterm infants receive expressed BM via tube feeding, and they are frequently treated with phototherapy. When parenteral nutrition (PN) is exposed to light and/or phototherapy, lipid peroxidation (LPO) increases. By light-protecting PN, morbidity and mortality are reduced in preterm infants through the reduction of oxidative stress. We aimed to investigate whether light-protecting breast milk could reduce LPO. Twelve mothers giving birth to a preterm infants of less than 32 weeks of gestational age were included. Transitional BM was collected and divided into three study groups; light-protected, ward light and phototherapy light. Baseline samples were collected after expression and the exposures started within one hour. Feeding syringe samples were exposed to light for 30 up to 360 min. Nasogastric tube samples were run through a tube under the same light conditions. Samples were stored in -80 °C until analyses of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and total antioxidant capacity (TAC). There were no significant differences in MDA, 4-HNE or TAC levels observed between the different study groups. This study indicates that the light exposure of expressed transitional BM does not affect LPO and the levels of MDA, 4-HNE or TAC.

The Impacts of Single Preterm Human Donor Milk Compared to Mother's Own Milk on Growth and Body Composition

(1) If mother´s own milk (MOM) is not available, pooled term human donor milk (HDM) is commonly used. Compared to MOM, term HDM contains less protein and fat and is associated with impaired growth. HDM from mothers of preterm infants is an alternative source and contains higher protein levels compared to term HDM, but the impacts on growth and body composition are unclear. (2) Methods: Infants born below 32 weeks of gestation and below 1500 g between 2017-2022, who underwent air displacement plethysmography (Pea Pod^®) to determine body composition (FFM: fat-free mass; FM: fat mass) at term-equivalent age, were included. A comparison between infants fed with MOM > 50% (MOM-group) and single preterm HDM > 50% (HDM-group) was conducted. (3) Results: In total, 351 infants (MOM-group: n = 206; HDM-group: n = 145) were included for the analysis. The median FFM-Z-score (MOM-group: -1.09; IQR: -2.02, 1.11; HDM-group: -1.13; IQR: -2.03, 1.12; p = 0.96), FM-Z-score (MOM-group: 1.06; IQR: -0.08, 2.22; HDM-group: 1.19; IQR: -0.14, 2.20; p = 0.09), and median growth velocity (MOM-group: 23.1 g/kg/d; IQR: 20.7, 26.0; HDM: 22.5 g/kg/d; IQR: 19.7, 25.8; p = 0.15) values were not significantly different between the groups. (4) Conclusion: Single preterm HDM is a good alternative to support normal growth and body composition.

Human milk pH is associated with fortification, postpartum day, and maternal dietary intake in preterm mother-infant dyads

OBJECTIVE

To compare pH of human milk types (mother's own milk (MOM), pasteurized donor human milk (PDHM), fortified MOM, and fortified PDHM) fed to preterm infants.

STUDY DESIGN

This observational study consisted of 63 mother-infant dyads < 34 weeks gestation. Human milk samples (n = 245), along with maternal factors, were collected for pH analysis. pH of MOM was analyzed over the course of lactation accounting for fortification status, postpartum day, and storage conditions.

RESULTS

Mean pH of MOM was slightly acidic at 6.60 ± 0.28, which was significantly higher (p < 0.05) than other milk types. pH of MOM varied by fortification, postpartum day, and maternal vegetable/fiber intake. There was a significant interaction between fortification status and postpartum day; pH of MOM decreased over time, while pH of fortified MOM increased over time.

CONCLUSION

pH of human milk varied by type. pH of MOM was significantly associated with fortification status, postpartum day, and maternal vegetable/fiber intake.

Short-term effects of fresh mother's own milk in very preterm infants

Fresh mother's own milk (MOM) can protect preterm infants from many complications. Often MOM is pasteurized for safety, which can deactivate cellular and bioactive components with protective benefits. Questions remain regarding whether pasteurized MOM provides the same benefits as fresh MOM. The aim of this study was to evaluate the association and feasibility of feeding very preterm infants with fresh MOM. This prospective cohort study included 157 very preterm infants born before 32 weeks' gestational age and with a birthweight below 1500 g. Of these, 82 infants were included in the fresh MOM without any processing group and 75 infants were included in the pasteurized never-frozen MOM (PNFMOM) group. The mortality rate, survival rate without severe complication, incidence of complications, feeding indexes and growth velocities were compared to assess the association and feasibility of feeding fresh MOM. Compared with the PNFMOM group, the fresh MOM group had a higher survival rate without severe complications (p = 0.014) and a lower incidence of bronchopulmonary dysplasia (p = 0.010) after adjustment for confounders. The fresh MOM group regained birthweight earlier (p = 0.021), reached total enteral feeding earlier (p = 0.024), and received total parenteral nutrition for less time (p = 0.045). No adverse events associated with fresh MOM feeding were recorded. Feeding fresh MOM may reduce the incidence of complications in very premature infants. Fresh MOM was shown to be a feasible feeding strategy to improve preterm infants' outcomes.

Source of human milk (mother or donor) is more important than fortifier type (human or bovine) in shaping the preterm infant microbiome

Milk fortifiers help meet the nutritional needs of preterm infants receiving their mother’s own milk (MOM) or donor human milk. We conducted a randomized clinical trial (NCT03214822) in 30 very low birth weight premature neonates comparing bovine-derived human milk fortifier (BHMF) versus human-derived fortifier (H2MF). We found that fortifier type does not affect the overall microbiome, although H2MF infants were less often colonized by an unclassified member of Clostridiales Family XI. Secondary analyses show that MOM intake is strongly associated with weight gain and microbiota composition, including Bifidobacterium, Veillonella, and Propionibacterium enrichment. Finally, we show that while oxidative stress (urinary F2-isoprostanes) is not affected by fortifier type or MOM intake, fecal calprotectin is higher in H2MF infants and lower in those consuming more MOM. Overall, the source of human milk (mother versus donor) appears more important than the type of milk fortifier (human versus bovine) in shaping preterm infant gut microbiota.

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Milk fortifier type (human versus bovine) has little impact on the preterm microbiome

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Milk source (mother versus donor) is strongly associated with microbiome composition

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Feeding mother’s own milk is linked to better weight gain and less gut inflammation

Free Fatty Acid and α-Lactalbumin-Oleic Acid Complexes in Preterm Human Milk Are Cytotoxic to Fetal Intestinal Cells in vitro

Human milk, the best enteral selection for a preterm infant, becomes altered during freezing and soluble free fatty acid is generated over time. Free fatty acids may form complexes, such as the oleic acid-bound protein called HAMLET (human α-lactalbumin made lethal to tumor cells). We determined the in vitro biological activity of preterm human milk protein-oleic complexes (HAMLET-like complexes) and tested the hypothesis that laboratory-synthesized HAMLET exhibits cytotoxicity in human immature epithelial intestinal cell culture. Thirty-four milk samples from 15 mothers of hospitalized preterm infants were donated over time. Milk fractions were tested repeatedly for FHs 74 Int and HIEC-6 fetal cell cytotoxicity, using a sensitive viability assay. Protein and fatty acid identities were confirmed by Western blot, high performance liquid chromatography, and mass spectrometry. Cytotoxicity of intestinal cells exposed to milk increased respective to milk storage time (p < 0.001) and was associated with free oleic acid (p = 0.009). Synthesized HAMLET was cytotoxic in cultures of both lines. Preterm milk samples killed most cells in culture after an average 54 days in frozen storage (95% C.I. 34–72 days). After prolonged storage time, preterm milk and HAMLET showed a degree of cytotoxicity to immature intestinal cells in culture.

Never‐breastfed children face a higher risk of suboptimal cognition at 2 years of corrected age: A multinational cohort of very preterm children

In a cohort of children born very preterm (VPT), we investigated the association between breast milk feeding (BMF) initiation and its duration on cognitive development at 2 years of corrected age. Data were obtained from the Effective Perinatal Intensive Care in Europe population‐based prospective cohort of children born <32 weeks of gestation, in 11 European countries, in 2011–2012. The study sample included 4323 children. Nonverbal cognitive ability was measured applying the Parental Report of Children's Abilities, except for France where the problem‐solving domain of the Ages & Stages Questionnaire was used. Verbal cognition was based on the number of words the child could say. To determine the association between BMF (mother's own milk) and nonverbal and verbal cognition (outcome categorized as optimal and suboptimal), adjusted risk ratios (aRRs) were estimated fitting Poisson regression models, with inverse probability weights to account for nonresponse bias. Overall, 16% and 11% of the children presented suboptimal nonverbal and verbal cognition, respectively. Never BMF was associated with a significantly increased risk for suboptimal nonverbal (aRR = 1.29, 95% confidence interval [CI] = 1.09–1.53) and verbal (aRR = 1.45, 95% CI = 1.09–1.92) cognitive development compared with those ever breastfed, after adjustment for perinatal and sociodemographic characteristics. Compared with children breastfed 6 months or more, children with shorter BMF duration exhibited a statistically nonsignificant elevated aRR. VPT children fed with breast milk had both improved nonverbal and verbal cognitive development at 2 years in comparison with never breastfed, independently of perinatal and sociodemographic characteristics. This study encourages targeted interventions to promote BMF among these vulnerable children.

In a European cohort of children born very preterm, 16% and 11% presented suboptimal nonverbal and verbal cognitive development, respectively.

Never‐breastfed children faced a higher risk of having suboptimal nonverbal and verbal cognition at 2 years of corrected age when compared with those who were breastfed, independently of perinatal and sociodemographic characteristics.

Breastfeeding support is a modifiable factor regardless of perinatal and sociodemographic characteristics, which reinforces the importance of specifically targeted interventions to protect, promote and support breast milk feeding in neonatal intensive care units and after discharge.

[Influence of the coronavirus disease 2019 pandemic on maternal breastfeeding for very low birth weight infants]

OBJECTIVES

To investigate the changes in the rate and volume of mother's own milk (MOM) feeding for very low birth weight infants (VLBWIs) hospitalized during the prevention and control of the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A retrospective analysis was performed on the medical data of the VLBWIs with a gestational age of <32 weeks who were born and admitted to the Neonatal Intensive Care Unit of Nanjing Maternal and Child Health Hospital from January 2019 to December 2020. The changes in the rate and volume of MOM feeding for VLBWIs during hospitalization were examined.

RESULTS

A total of 301 VLBWIs were enrolled. According to the timing of COVID-19 outbreak, these infants were divided into a pre-CIVID-19 group with 205 VLBWIs and a post-COVID-19 group with 96 VLBWIs. Compared with the pre-CIVID-19 group, the post-COVID-19 group had a significantly lower rate of MOM feeding within 28 days after birth and during hospitalization (P<0.05), a significantly lower volume of MOM feeding within 0-7 days, 0-14 days, and 0-28 days after birth (P<0.05), and significantly higher incidence rates of moderate-to-severe bronchopulmonary dysplasia and feeding intolerance (P<0.05).

CONCLUSIONS

The COVID-19 pandemic has a significant impact on MOM feeding for VLBWIs, and there are significant reductions in the rate and volume of MOM feeding for VLBWIs within 28 days after birth, as well as a significant reduction in the rate of MOM feeding during hospitalization.

Human Milk Lipids Induce Important Metabolic and Epigenetic Changes in Neonates

Lipids are a major source of energy during the fetal/neonatal period. Most are received from the mother, transplacentally during the intrauterine period or via maternal milk after birth. However, in addition to the known nutritional roles, lipids are now known to bind a variety of cellular receptors to regulate specific patterns in metabolism and gene expression. The expression of these receptors is regulated by various genetic and environmental stimuli, and ligation can activate positive-feedback loops in the expression and the activity of downstream signaling pathways. The authors summarize the role of lipid ligands, cognate receptors, epigenetic regulation, and downstream signaling.

Nutrition for the micro preemie: Beyond milk

Nutritional support is a fundamental component of the care of the extremely preterm infant, including the "micro preemie" (here defined as a baby born weighing less than 500 g), but goes beyond considerations of milk as a food. This is because milk from an infant's own mother, unlike currently available substitutes, additionally provides invaluable non-nutritive benefits. Nutritional support requires suitable devices or techniques to administer nutrients enterally or intravenously, products shown to be safe in preterm populations, and efficacy demonstrated in respect of important functional outcomes. Sadly, preterm feeding remains characterised by a deficit of evidence. In this chapter, we will briefly describe the history of preterm nutrition, discuss current enteral and parenteral practice, important evidence gaps, a summary of approaches for evaluating nutritional practice, and key considerations for future endeavour. Our discussion refers to all extremely preterm infants and it not confined to the micro preemie.

Pre-digestion of the lipids in infant formula affects gut maturation of the preterm pig

Preterm birth is associated with increased risk of complications, specifically with regards to the gastrointestinal tract. These complications mainly include the maldigestion and malabsorption of nutrients resulting from the immaturity of the small intestine. The current study investigated whether pre-digestion of fat in infant formula would affect the developmental remodeling of the structure of the small intestine mucous membrane. Three groups of premature piglets (corresponding to 30–32 week of human gestation) were used in the study: the first group, not subjected to any treatment and euthanized within 2 hours after caesarian delivery, was used as the control group (PT group), the second group, was fed an infant formula—IF (SPT group), and the third group was fed a lipase pre-hydrolyzed infant formula—hIF (PPT group). Feeding preterm piglets with an infant formula for 14 days stimulated intestinal maturation (in SPT and PPT groups). However, pre-digestion of the infant formula with lipase significantly increased proliferative activity and intensity of apoptosis in the small intestine epithelium, resulting in more rapid enterocyte turnover. The data obtained not only confirm that starting enteral feeding directly after birth stimulates developmental and structural changes in the small intestine, but also highlighted the importance of lipid digestion for enterocyte turnover and speeding up of intestinal maturation in preterm piglets. The latest is of high importance for the proper gut development of preterm children.

Longitudinal Serum Metabolomics in Extremely Premature Infants: Relationships With Gestational Age, Nutrition, and Morbidities

An increasing number of extremely premature infants survive the neonatal period and beyond. Little is known about the maturation of the preterm infant’s metabolome and its relation to the development of morbidities. Using 1H-NMR, we investigated the serum metabolic profile of 87 infants born at a gestational age (GA) <28 weeks [mean GA (SD) 25.4 (1.4) weeks] in samples longitudinally collected from birth to term equivalent age. The infant metabolome was analyzed in relation to GA, postnatal age, nutrition, and preterm morbidities. At postnatal day 1, low GA correlated with high levels of 3-hydroxyisobutyrate, acetate, acetoacetate, acetone, formate, glucose, and valine. Nearly all quantified metabolites displayed postnatal concentration changes. For example, the two phospholipid-related metabolites myo-inositol and ethanolamine displayed a similar decline from birth over the first weeks of life, irrespectively of GA. The proportion of enteral/parenteral energy intake in the first 28 days significantly correlated with mean levels of 52% of the analyzed metabolites. Low enteral energy intake was associated with high serum levels of 3-hydroxyisobutyrate, creatinine, glucose, glycerol, histidine, lactate, leucine, lysine, methionine, ornithine, phenylalanine, proline, threonine, and uridine. There were also significant correlations between high enteral intake and high serum levels of isoleucine and tyrosine. Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) outcomes were not significantly associated with metabolite levels in the neonatal period after correcting for multiple testing. In conclusion, the serum metabolome of extremely premature infants changes substantially in the neonatal period, largely driven by the gradual transfer from total parenteral nutrition to full enteral feeding. Further studies are needed to disentangle the intricate relationships between the metabolome, nutritional management, GA, and the development of preterm morbidities.

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.

Epidermal growth factor concentration in milk of healthy water buffaloes (Bubalus bubalis)

Epidermal growth factor (EGF) has biological roles, including embryonic organ development, breast morphogenesis, breast cell proliferation, and mammary development. This study aimed to measure EGF concentration and evaluate its relationship with somatic cell count (SCC) in healthy water buffaloes (Bubalus bubalis) milk. The study material was constituted of 120 milk samples obtained from 30 healthy water buffaloes between the ages of 3 - 6 years, negative for California mastitis test and SCC less than 3.00 × 10⁵ cells mL^-1 milk. In milk serum samples, the EGF concentration was measured using a bovine-specific enzyme-linked immunosorbent assay kit. Epidermal growth factor concentration in the buffalo milk was ranged from 4.30 to 9.80 ng mL^-1, with a mean of 8.30 ± 1.50 ng mL^-1. Positive correlation between milk SCC values and EGF concentrations was recorded in water buffaloes. Further research is required to evaluate the content of milk EGF in different species of animals because of the EGF effective role in mammary gland and intestinal mucosa.

Preterm nutrition and neurodevelopmental outcomes

Survival of preterm infants has been steadily improving in recent years because of many recent advances in perinatal and neonatal medicine. Despite these advances, the growth of survivors does not reach the ideal target level of the normal fetus of the same gestational age. Postnatal weight gain is often not achieved because extrauterine growth has higher energy requirements than intrauterine growth, due to the intensive care environment, illness and inadequate nutrition. Although many other factors influence infant brain development, including family socioeconomic and educational background, the role of nutrition is considerable and fortunately, amenable to intervention. In the preterm neonate, the brain is the most metabolically demanding organ, consuming the largest proportions of energy and nutrient intake for its function and programmed growth and maturation. Weight gain, linear and head circumference growth are all markers of nutritional status and are independently associated with long-term neurodevelopment. Brain development is not only the result of nutrients intake, but in addition, of the interaction with growth factors which depend on adequate nutrient supply and overall health status. This explains why conditions such as sepsis, necrotizing enterocolitis and chronic lung disease alter the distribution and accretion of nutrients thereby suppressing growth factor synthesis. In this review, we will focus on the direct role of nutrition on neurodevelopment, emphasizing why it should be started without delay. The nutritional requirements of the preterm infant will be discussed, followed by the effects of general nutritional interventions and specific nutrients, as well as the role of nutritional supplements on neurodevelopment. The primordial role of human breast milk, breast milk fortifiers and human milk oligosaccharides will be discussed in detail. We will also examine the role of nutrition in preventing neonatal complications which can affect neurodevelopment in their own right.

The Effect of Pasteurization on the Antioxidant Properties of Human Milk: A Literature Review

High rates of oxidative stress are common in preterm born infants and have short- and long-term consequences. The antioxidant properties of human milk limits the consequences of excessive oxidative damage. However, as the mother's own milk it is not always available, donor milk may be provided as the best alternative. Donor milk needs to be pasteurized before use to ensure safety. Although pasteurization is necessary for safety reasons, it may affect the activity and concentration of several biological factors, including antioxidants. This literature review describes the effect of different pasteurization methods on antioxidant properties of human milk and aims to provide evidence to guide donor milk banks in choosing the best pasteurization method from an antioxidant perspective. The current literature suggests that Holder pasteurization reduces the antioxidant properties of human milk. Alternative pasteurization methods seem promising as less reduction is observed in several studies.

Comparison of methods for pre-processing, exosome isolation, and RNA extraction in unpasteurized bovine and human milk

Milk is a highly complex, heterogeneous biological fluid that contains non-nutritive, bioactive extracellular vesicles called exosomes. Characterization of milk-derived exosomes (MDEs) is challenging due to the lack of standardized methods that are currently being used for milk pre-processing, storage, and exosome isolation. In this study, we tested: 1) three pre-processing methods to remove cream, fat, cellular debris, and casein proteins from bovine milk to determine whether pre-processing of whole milk prior to long-term storage improves MDE isolations, 2) the suitability of two standard exosome isolation methods for MDE fractionation, and 3) four extraction protocols for obtaining high quality RNA from bovine and human MDEs. MDEs were characterized via Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and western immunoblotting for CD9, CD63, and Calnexin protein markers. We also present an optimized method of TEM sample preparation for MDEs. Our results indicate that: 1) Removal of cream and fat globules from unpasteurized bovine milk, prior to long-term storage, improves the MDE yield but not purity, 2) Differential ultracentrifugation (DUC) combined with serial filtration is better suited for bovine MDE isolation compared to ExoQuick (EQ) combined with serial filtration, however both methods were comparable for human milk, and 3) TRIzol LS is better suited for RNA extraction from bovine MDEs isolated by EQ and DUC methods. 4) TRIzol LS, TRIzol+RNA Clean and Concentrator, and TRIzol LS+RNA Clean and Concentrator methods can be used for RNA extractions from human MDEs isolated by EQ, yet the TRIzol LS method is better suited for human MDEs isolated by DUC. The QIAzol + miRNeasy Mini Kit produced the lowest RNA yield for bovine and human MDEs.

Sex Differences in Gut Microbial Development of Preterm Infant Twins in Early Life: A Longitudinal Analysis

Infant gut microbiota plays a vital role in immune response, mediates neurobehavioral development and health maintenance. Studies of twins’ gut microbiota found that gut microbiota composition and diversity tend to be mature and stable with increasing postnatal age (PNA). Preterm infant gut microbiome shifts dramatically when they were staying in the neonatal intensive care unit (NICU). Compositions and shifting characteristics of gut microbiota among neonatal preterm twins and triplets during their early life are still unknown, which impedes a better understanding of the mechanism underpinning neurobehavioral development and precise intervention/health of preterm neonates. This longitudinal cohort study used a twins/triplets design to investigate the interaction of genetic (e.g., male vs. female) and environmental factors influencing the development of the gut microbiome in early life. We included 39 preterm infants, 12 were Female twins/triplets (Female T/T) including 3 twins pairs and 2 triplets, 12 were male twins (Male T) including 6 twins pairs, and 15 were mixed-sex twins/triplets (Mix T/T) including 6 twins pairs and 1 triplet (8 females and 7 males) during the first four weeks of NICU stay. Weekly gut microbiota patterns between females and males were compared by linear discriminant analysis (LDA) effect size (LEfSe). Metagenomics function of gut microbiota was predicted by using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). Weekly function (KEGG pathways) differences between females and males were detected by using Statistical Analysis of Metagenomic Profiles (STAMP). Results found that female pairs and male pairs were significantly different in gut microbiome diversity, compositions, and predicted metabolic profiles, importantly, females and males were also significantly dissimilar within their co-twin/triplet pairs of the mixed-sex group, infants of co-twins/triplets shared more similar features than un-related infants from different twins’ pair. Future research developing personalized interventions for vulnerable high-risk infants should consider sex, and the interaction of sex and environmental factors.

Maternal effects in mammals: Broadening our understanding of offspring programming

The perinatal period is a sensitive time in mammalian development that can have long-lasting consequences on offspring phenotype via maternal effects. Maternal effects have been most intensively studied with respect to two major conditions: maternal diet and maternal stress. In this review, we shift the focus by discussing five major additional maternal cues and their influence on offspring phenotype: maternal androgen levels, photoperiod (melatonin), microbiome, immune regulation, and milk composition. We present the key findings for each of these topics in mammals, their mechanisms of action, and how they interact with each other and with the maternal influences of diet and stress. We explore their impacts in the contexts of both predictive adaptive responses and the developmental origins of disease, identify knowledge gaps and research opportunities in the field, and place a particular emphasis on the application and consideration of these effects in non-model species and natural ecological systems.

Concentrating human milk: an innovative point-of-care device designed to increase human milk feeding options for preterm infants

OBJECTIVE

The purpose of this study was to determine whether a point-of-care osmotic device concentrates important human milk (HM) nutrients to support feeding neonates requiring high-nutrient, low-volume feedings.

STUDY DESIGN

Raw and pasteurized HM samples were concentrated to determine the effects of time and temperature on concentration. Concentrated samples were compared with matched baseline samples to measure changes in selected nutrient concentrations. Furthermore, changes in concentration of certain bioactive components of raw milk samples were measured.

RESULT

The device significantly increased the concentrations of the majority of the measured nutrient and bioactive levels (p < 0.05). Increasing temperature of HM from 4 to 37 °C increased the concentration rate >30%. In all cases, the concentration rate of pasteurized HM was greater than that of raw HM.

CONCLUSIONS

The osmotic concentration of HM is a promising option for neonatal nutrition. Further studies are needed to establish an evidence base for the practical applications of this point-of-care device.

Unpasteurised maternal breast milk is positively associated with growth outcomes in extremely preterm infants

AIM

Extrauterine growth restriction is common among extremely preterm infants. We explored whether intake of unpasteurised maternal milk (MM) and pasteurised donor milk (DM) was associated with longitudinal growth outcomes and neonatal morbidities in extremely preterm infants.

METHODS

Observational study of 90 preterm infants born between 2013 and 2015 in Gothenburg, Sweden. Data were prospectively collected on nutritional and breast milk intakes during the first 28 days.

RESULTS

Ninety infants (39 girls and 51 boys) with a median gestational age of 25.3 (22.7-27.9) weeks were evaluated. MM intake (mL/kg/d) correlated positively with almost all z-scores for weight, length and head circumference at 28 postnatal days and at postmenstrual age (PMA) 32 and 36 weeks. After multivariable adjustment, MM intake and weight z-score at 28 postnatal days and at PMA 32 and 36 weeks remained significantly associated. Infants consuming ≥80% MM had more favourable weight z-scores at PMA 32 and 36 weeks. Intake of DM did not correlate with any growth outcomes. Infants without retinopathy of prematurity had a significantly higher intake of MM (mL/kg/d).

CONCLUSION

Unpasteurised MM was positively associated with longitudinal growth outcomes. Motivating mothers to provide their infants with their own milk after preterm birth should be emphasised.

Donated Human Milk as a Determinant Factor for the Gut Bifidobacterial Ecology in Premature Babies

Correct establishment of the gut microbiome is compromised in premature babies, with Bifidobacterium being one of the most affected genera. Prematurity often entails the inability to successfully breastfeed, therefore requiring the implementation of other feeding modes; breast milk expression from a donor mother is the recommended option when their own mother’s milk is not available. Some studies showed different gut microbial profiles in premature infants fed with breast milk and donor human milk, however, it is not known how this affects the species composition of the genus Bifidobacterium. The objective of this study was to assess the effect of donated human milk on shaping the gut bifidobacterial populations of premature babies during the first three months of life. We analyzed the gut bifidobacterial communities of 42 premature babies fed with human donor milk or own-mother milk by the 16S rRNA–23S rRNA internal transcriber spaces (ITS) region sequencing and q-PCR. Moreover, metabolic activity was assessed by gas chromatography. We observed a specific bifidobacterial profile based on feeding type, with higher bifidobacterial diversity in the human donor milk group. Differences in specific Bifidobacterium species composition may contribute to the development of specific new strategies or treatments aimed at mimicking the impact of own-mother milk feeding in neonatal units.

Predicted Metabolic Pathway Distributions in Stool Bacteria in Very-Low-Birth-Weight Infants: Potential Relationships with NICU Faltered Growth

Many very-low-birth-weight (VLBW) infants experience growth faltering in early life despite adequate nutrition. Early growth patterns can affect later neurodevelopmental and anthropometric potentials. The role of the dysbiotic gut microbiome in VLBW infant growth is unknown. Eighty-four VLBW infants were followed for six weeks after birth with weekly stool collection. DNA was extracted from samples and the V4 region of the 16S rRNA gene was sequenced with Illumina MiSeq. A similar microbiota database from full-term infants was used for comparing gut microbiome and predicted metabolic pathways. The class Gammaproteobacteria increased or remained consistent over time in VLBW infants. Out of 228 metabolic pathways that were significantly different between term and VLBW infants, 133 pathways were significantly lower in VLBW infants. Major metabolic differences in their gut microbiome included pathways involved in decreased glycan biosynthesis and metabolism, reduced biosynthetic capacity, interrupted amino acid metabolism, changes that could result in increased infection susceptibility, and many other system deficiencies. Our study reveals poor postnatal growth in a VLBW cohort who had dysbiotic gut microbiota and differences in predicted metabolic pathways compared to term infants. The gut microbiota in VLBW infants likely plays an important role in postnatal growth.

[Research advances in the effect of bioactive substances in breast milk on the growth and development of infants]

There are various types of bioactive substances in human breast milk, such as active proteins, growth factors, cytokines, oligosaccharides, probiotics and cells. Many studies have shown that these bioactive substances in breast milk have important protective effects on infant growth and development, including anti-bacterial and anti-viral effects and the promotion of infant growth and development and immunologic maturation. They can also reduce the incidence rate of infectious diseases in infants, improve neural development in preterm infants, and reduce the risk of obesity and diabetes in future. However, there is still no clinical evidence for the effects of several active substances in breast milk, and their immunoregulatory mechanism remains unclear. Therefore, further studies are needed for clarification.

Screening and novel therapies for retinopathy of prematurity - A review

With current screening for sight threatening retinopathy of prematurity (ROP) <10% of screened infants need treatment. Prediction models based on birth characteristics, postnatal weight gain and other factors have been developed to reduce examinations in low-risk infants. A model based on advanced statistics using data from >7000 infants registered in the Swedish ROP registry is being developed. Based on birth characteristics only, it appears to predict total risk of ROP-treatment as well as models including weight measurements. Treatment risk peaked at 12 weeks of age. Laser therapy is the method of choice for severe ROP. Anti-VEGF therapies are implemented worldwide despite insufficient knowledge of choice of drug, dosage and long term systemic effects. Prevention of ROP may be achieved through oxygen control and provision of the mother's breastmilk. Other interventions such as supplementation with long chain polyunsaturated fatty acids and preservation of fetal haemoglobin are investigated.