Total antioxidant status in fresh and stored human milk from mothers of term and preterm neonates

The Effect of Breast Milk from Different Lactation Stages on in Vitro Wound Healing

Objective: Wound healing is a complex and dynamic process essential for restoring tissue integrity and homeostasis. It is thought that breast milk contributes positively to the wound healing process, thanks to the components it contains. The aim of this study is to compare the effects of breast milk on the wound healing process at different lactation stages and to evaluate the underlying mechanism(s). Materials and Methods: The effects of breast milk from different lactation stages (colostrum, transitional, and mature milk) on wound healing were determined by in vitro scratch assay in L929 fibroblast cells. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), total oxidant, and antioxidant capacity were used to confirm antioxidant effects. The effect of breast milk on netrin-1 levels in L929 cells was elucidated by ELISA. Results: Breast milk at different lactation stages promoted wound healing. While the wound closure percentage was determined as 48.7% in the control group, this rate was determined to be the highest at 81.6% in the mature milk group (p:0.0002). The free radical scavenging capacity of colostrum, transitional, and mature milk with DPPH was determined as 49.69%, 60.64%, and 80.85%, respectively, depending on the lactation stages. Netrin-1 levels detected by ELISA were determined as 490.1 ± 6.5 pg/mL in the control group, while the lowest level was determined as 376.6 ± 4.5 pg/mL in mature milk (p:0.0003). Conclusions: Breast milk, especially mature milk, promoted wound healing on L929 cells by suppressing netrin-1 levels and scavenging free radicals.

Point-of-care human milk concentration by passive osmosis: comprehensive analysis of fresh human milk samples

OBJECTIVE

Preterm infants need enrichment of human milk (HM) for optimal growth. This study evaluated a novel, point-of-care human milk concentration (HMC) process for water removal from fresh HM samples by passive osmotic concentration.

STUDY DESIGN

Nineteen fresh HM samples were concentrated by incubation with the HMC devices for 3 h at 4 °C. Pre- and post-concentration HM samples were compared by HM properties for: pH, osmolality, macronutrients, enzyme activity, bioactive, and total cell viability.

RESULTS

Passive osmotic concentration reduced HM volume by an average of 16.3% ± 3.8% without a significant effect on pH or cell viability. Ten of the 41 HM components did not differ significantly (p > 0.05) between pre- and post-concentration samples. Twenty-three increased within the expected range by volume reduction. Six increased more than expected, two less than expected, and none decreased significantly.

CONCLUSION

Passive osmotic concentration of fresh HM can concentrate HM components by selective removal of water. HM osmolality and pH remained within neonatal feeding parameters.

Influence of Maternal Dietary Pattern on the Pro-Oxidant and Antioxidant Status of Mother's Own Milk

BACKGROUND

Human milk is essential for a child's best development. However, what a mother eats while breastfeeding can directly influence the composition of mother's milk.

RESEARCH AIM

This study aimed to assess the antioxidant-oxidant profile of human milk and establish a connection between this profile and the dietary habits of the mothers.

METHODS

A cross-sectional study was conducted at the Hospital Infantil e Maternidade Alzir Bernardino Alves (HIMABA), located in the municipality of Vila Velha-ES, Brazil. The sample included 98 participants. All volunteers completed a structured interview and a Food Frequency Questionnaire. Approximately 5-10 ml of colostrum, transitional milk, and mature milk were manually collected. The antioxidant activity of human milk was assessed using the colorimetric method for free radical scavenging with 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid. Oxidative stress was determined by measuring lipid peroxidation through malondialdehyde concentration, evaluating advanced oxidation protein products, and assessing total protein content using the Bradford method.

RESULTS

The antioxidant profile of colostrum was higher than that observed in later phases of milk, whereas pro-oxidants increased in later phases. Maternal dietary patterns influenced the pro-oxidant status of human milk. Participants with a higher daily intake of milk, dairy products, vegetable oils, olive oils, and legumes exhibited lower levels of lipid peroxidation in colostrum, transition milk, and mature milk, respectively.

CONCLUSIONS

Our study highlights the vital role of a balanced maternal diet in shaping the pro-oxidant status of human milk, with implications for infant health.

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.

Effects of Different Thawing and Warming Processes on Human Milk Composition

The composition of human milk is influenced by storage and processing practices. The effects of thawing and warming practices on human milk composition remain poorly studied despite their prevalence in home, research, and donor milk bank settings. This review comprehensively examines the impact of different thawing and warming methods on nutritional and bioactive human milk components. While some components such as carbohydrates and minerals remain stable under most typical thawing and warming conditions, others, such as fat, immune proteins, bacterial and human cells, and peptide amine hormones, are sensitive to warming. This review has identified that the data on the effects of milk thawing and warming is limited and often contradictory. Given that numerous important components of milk are diminished during cold storage, it is important that thawing and warming practices do not lead to further loss of or alterations to beneficial milk components. Further work in this field will facilitate greater standardization of thawing methods among researchers and underpin recommendations for thawing and warming of expressed milk for parents.

Wayfinding through the "ocean of the great unknown": how lactating parents establish a direct breastfeeding relationship with an infant with critical CHD

INTRODUCTION

Lactating parents of infants hospitalised for critical congenital heart disease (CHD) face significant barriers to direct breastfeeding. While experiences of directly breastfeeding other hospitalised neonates have been described, studies including infants with critical CHD are scarce. There is no evidence-based standard of direct breastfeeding care for these infants, and substantial practice variation exists.

AIM

To explain how direct breastfeeding is established with an infant hospitalised for critical CHD, from lactating parents' perspectives.

MATERIALS & METHODS

This study is a qualitative grounded dimensional analysis of interviews with 30 lactating parents of infants with critical CHD who directly breastfed within 3 years. Infants received care from 26 United States cardiac centres; 57% had single ventricle physiology. Analysis included open, axial, and selective coding; memoing; member checking; and explanatory matrices.

RESULTS

Findings were represented by a conceptual model, "Wayfinding through the 'ocean of the great unknown'." The core process of Wayfinding involved a nonlinear trajectory requiring immense persistence in navigating obstacles, occurring in a context of life-and-death consequences for the infant. Wayfinding was characterised by three subprocesses: navigating the relationship with the healthcare team; protecting the direct breastfeeding relationship; and doing the long, hard work. Primary influencing conditions included relentless concern about weight gain, the infant's clinical course, and the parent's previous direct breastfeeding experience.

CONCLUSIONS

For parents, engaging in the Wayfinding process to establish direct breastfeeding was feasible and meaningful - though challenging. The conceptual model of Wayfinding explains how direct breastfeeding can be established and provides a framework for research and practice.

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.

Odor changes in breast milk during different storage temperatures and times using GC × GC-O-MS

Breastfeeding is generally the preferred way that most mothers will choose. It is common to store expressed breast milk in the refrigerator in many families. However, there is a phenomenon that infants may refuse to consume stored breast milk, presumably due to changes in odor. Thus, the odor changes in breast milk stored at 4 °C for 72 h and at -20 °C for 60 d were studied. Compared with fresh breast milk, 7 and 16 odor compounds were newly detected by SPME and GC × GC-O-MS when breast milk was stored at 4 and -20 °C, respectively. The concentration of (E)-2-decenal, octanal, hexanal, 1-octen-3-ol, 2-pentylfuran, lauric acid, decanoic acid and hexanoic acid significantly increased after storage at 4 °C for 36 h and -20 °C for 30 d. In addition, the proportion of acids increased, whereas that of aldehydes decreased during storage. Chemometric analysis with OPLS-DA suggested that breast milk should be stored at 4 °C for less than 36 h and at -20 °C for less than 30 d for maximum preservation of the original odors.

Infant factors that impact the ecology of human milk secretion and composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 3

Infants drive many lactation processes and contribute to the changing composition of human milk through multiple mechanisms. This review addresses the major topics of milk removal; chemosensory ecology for the parent-infant dyad; the infant's inputs into the composition of the human milk microbiome; and the impact of disruptions in gestation on the ecology of fetal and infant phenotypes, milk composition, and lactation. Milk removal, which is essential for adequate infant intake and continued milk synthesis through multiple hormonal and autocrine/paracrine mechanisms, should be effective, efficient, and comfortable for both the lactating parent and the infant. All 3 components should be included in the evaluation of milk removal. Breastmilk "bridges" flavor experiences in utero with postweaning foods, and the flavors become familiar and preferred. Infants can detect flavor changes in human milk resulting from parental lifestyle choices, including recreational drug use, and early experiences with the sensory properties of these recreational drugs impact subsequent behavioral responses. Interactions between the infant's own developing microbiome, that of the milk, and the multiple environmental factors that are drivers-both modifiable and nonmodifiable-in the microbial ecology of human milk are explored. Disruptions in gestation, especially preterm birth and fetal growth restriction or excess, impact the milk composition and lactation processes such as the timing of secretory activation, adequacy of milk volume and milk removal, and duration of lactation. Research gaps are identified in each of these areas. To assure a sustained and robust breastfeeding ecology, these myriad infant inputs must be systematically considered.

Effects of Sepsis on Immune Response, Microbiome and Oxidative Metabolism in Preterm Infants

This is a narrative review about the mechanisms involved in bacterial sepsis in preterm infants, which is an illness with a high incidence, morbidity, and mortality. The role of the innate immune response and its relationship with oxidative stress in the pathogenesis are described as well as their potential implementation as early biomarkers. Moreover, we address the impact that all the mechanisms triggered by sepsis have on the dysbiosis and the changes on neonatal microbiota.

The effects of freezing and thawing on mature human milk's contains: A systematic review

OBJECTIVE

To conduct a systematic review on the effects of freezing and thawing mature human milk at -18 to -20°C for different periods of time on the macronutrients, micronutrients and bioactive content of milk.

DESIGN

Before starting the research, the study protocol was recorded in the 'PROSPERO' database. Eleven databases were searched, and eight studies were included in this review. The articles were published between January 2010 and June 2020.

MEASUREMENTS AND FINDINGS

Total protein content increased when milk was frozen for 2 days, but this decreased significantly when milk was frozen for >1 week. Total carbohydrate content also increased when milk was frozen for 2 days, and no significant change was observed when milk was frozen for >1 week. Energy content decreased when milk was frozen for >8 weeks. Total fat content decreased as the freezing period of milk increased, and total free fatty acid content increased. Thirty days of freezing led to a non-significant decrease in the vitamin E content of milk. Freezing did not lead to changes in immunological factors in human milk, but decreases in glutathione peroxidase, antioxidant capacity and lactoferrin were observed.

KEY CONCLUSIONS

In order to maintain the nutritional and immunological properties of human milk after freezing and thawing, families, especially mothers, should be informed about the effects of storing milk this way. After expressing milk, it is recommended that the date should be written on the freezer bag, so that milk is frozen for a shorter period of time before use.

Experiences of mothers of NICU preterm infants in milk management out of the hospital: a qualitative study

BACKGROUND

Human milk is important for the health and development of preterm infants. China's neonatal intensive care units (NICUs) have adopted the management system of maternal-infant separation. Human milk received and used by NICUs is managed by the infants' families in the out-of-hospital environment. There is scant publication on mothers' opinions on out-of-hospital human milk management. This study aimed to explore the experiences of Chinese mothers providing their infants in the NICUs with human milk expressed outside of the hospital.

METHODS

Semi-structured interviews were conducted with 23 participants recruited from June 2020 to November 2020, who transported their human milk to the human milk bank of Women's Hospital School of Medicine Zhejiang University during the hospitalization of their preterm infants. This study adopted a qualitative research approach with thematic analysis.

RESULTS

Three main themes were identified: 1) awareness of human milk management and a willingness to adopt it; 2) lack of standardization regarding expressing, storing, and transporting expressed human milk; and 3) the need for more external support. Theme 2 additionally has three sub-themes: I) differentiation of preparations before human milk expression; II) differentiation of devices for human milk expression; and III) insufficient knowledge and understanding.

CONCLUSIONS

In this study, all participants who received health education showed enthusiasm for participating in out-of-hospital human milk management. However, most participants had questions during the implementation process. Medical staff should provide professional and continuous external support to support mothers in implementing human milk management.

The Influence of Time and Temperature on Human Milk Storage Antioxidant Properties, Oxidative Stress, and Total Protein

BACKGROUND

Human milk is an essential source of nutrition for an infant's health. When breastfeeding working mothers or students, for example, are unable to breastfeed, storing their milk is recommended. Therefore, it is crucial to know the storage conditions to ensure their antioxidant capacity and avoid oxidative damage.

RESEARCH AIM

To evaluate the stability of the antioxidant and pro-oxidant profiles and the amount of total protein in fresh human milk after different storage times (1, 2, 7, 14, and 21 days) and temperatures (4 ºC and -20 ºC).

METHODS

This was a prospective, longitudinal, and observational study with milk samples grouped according to age for comparisons, which included 20 lactating women. The antioxidant activity was evaluated using the colorimetric methods of free radical scavenging 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and the decrease of ferric ion. Oxidative stress was determined by the lipid peroxidation product formation through malondialdehyde concentration, and the total protein content was assessed by the Bradford method.

RESULTS

The antioxidant profile of human milk was maintained with minimal losses until the 14^th day when stored at 4 ºC and -20 ºC. The evolution of malondialdehyde concentration over storage revealed significant changes only 21 days after human milk storage at 4 ºC. There was no change in the value of total protein content.

CONCLUSIONS

To sum up, there is no difference in the storage of human milk at a temperature of 4 °C or -20 °C over 14 days. Therefore, the lactating woman may choose the most convenient way of storage.

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.

Analysis of the composition and antioxidant status of breast milk in women giving birth prematurely and on time

Background

Breastfeeding with mother’s milk is the best form of nutrition not only for newborn babies, but especially for premature babies, due to the health benefits of taking human food.

Objectives

The aim of the study was to examine the basic composition, cortisol concentration and antioxidant status of breast milk samples from women giving birth before 37 weeks of pregnancy and comparing it with milk samples from women giving birth after 37 weeks of pregnancy.

Methods

The material for the study was milk taken from women giving birth before and after 37 weeks of pregnancy. The basic composition of breast milk was determined using a MIRIS analyzer, cortisol concentration in samples by an enzyme-linked immunosorbent test and their total antioxidant status was assessed by DPPH and FRAP methods.

Results

It has been shown that the concentration of cortisol in samples of human milk in the group of women giving birth before 37 weeks was 13.95 ng / ml [4,71–86,84], while in the group of women giving birth after week 37 of pregnancy—10.31 ng / ml [2.35-39-02] (p = 0.014), while% inhibition of DPPH was 65.46% and 58.30%, respectively (p = 0.014).

Conclusions

Milk from women giving birth prematurely is qualitatively different from the milk of women giving birth on time. The total antioxidant status of preterm milk is higher than term milk, which promotes the development of premature babies. Higher cortisol levels in samples from women giving birth before 37 weeks of pregnancy may stimulate the digestive system.

Is the Antioxidant Capacity of Stored Human Milk Preserved?

Background: In the neonatal intensive care unit (NICU) expressed mothers' milk usually is stored frozen until used. We found that when human milk was stored at -20°C for up to 9 months there were reduced bacterial counts and pH, increased free fatty acids, but unchanged immune proteins. Antioxidant protection is an important benefit of human milk. Few studies have evaluated long-term effects of cold storage on the antioxidant capacity of human milk. We hypothesized that the antioxidant capacity of human milk is affected adversely by long-term storage at -20°C. Objective: To study the impact of long-term cold storage on the oxidative capacity of human milk and the biological impact of these changes on macromolecular constituents of human milk. Methods: Freshly expressed milk was obtained from mothers in the NICU, stored at -20°C for 6 months, and compared with the baseline. Paired samples were analyzed for glutathione, hydrogen peroxide (H₂O₂), 8-isoprostane, catalase, and superoxide dismutase. Results: There was no change in H₂O₂ concentration between baseline and 6 months. Significant reductions from baseline in both catalase and superoxide dismutase concentrations and activities, total glutathione, oxidized glutathione, reduced glutathione, and the ratio of reduced to oxidized glutathione were observed (p < 0.05). There was a significant increase in 8-isoprostane concentrations (p < 0.001). Conclusion: These data indicate significant changes in antioxidant capacity of human milk, including oxidation of macromolecules, after storage at -20°C for 6 months. The clinical implication of these findings may explain the nonuniform protection against oxidant disease in preterm infants fed human milk.

Antioxidative Molecules in Human Milk and Environmental Contaminants

Breastfeeding provides overall beneficial health to the mother-child dyad and is universally recognized as the preferred feeding mode for infants up to 6-months and beyond. Human milk provides immuno-protection and supplies nutrients and bioactive compounds whose concentrations vary with lactation stage. Environmental and dietary factors potentially lead to excessive chemical exposure in critical windows of development such as neonatal life, including lactation. This review discusses current knowledge on these environmental and dietary contaminants and summarizes the known effects of these chemicals in human milk, taking into account the protective presence of antioxidative molecules. Particular attention is given to short- and long-term effects of these contaminants, considering their role as endocrine disruptors and potential epigenetic modulators. Finally, we identify knowledge gaps and indicate potential future research directions.

The Revolution of Breast Milk: The Multiple Role of Human Milk Banking between Evidence and Experience-A Narrative Review

The review recalls the importance of breast milk and deepens the theme of human milk banking, a virtuous reality that is expanding all over the world but is still little known. In the last 15 years, modern biological technologies have crystallized the concept of uniqueness and irreproducibility of human milk, by establishing three new principles: first: human milk: a "life-saving" drug; second: human milk: the best food for preterm infants; and third: human milk: the main component of premature infant care. Our experience teaches us that human milk banking plays many roles that need to be known and shared.

Stability of the Antimicrobial Capacity of Human Milk Against Cronobacter Sakazakii During Handling

BACKGROUND

Neonatal infections with Cronobacter sakazakii have recently been associated with the consumption of expressed human milk.

STUDY AIMS

(1) To evaluate whether human milk has antimicrobial capacity against C. sakazakii and (2) to determine the stability of its capacity when it is subjected to various treatments.

METHODS

The antimicrobial capacity of human milk against C. sakazakii was evaluated using an observational, cross-sectional, comparative design. Mature human milk samples (N = 29) were subjected to different treatments. After incubation at 37°C for 72 hr, samples were compared with fresh milk on the stability of their antimicrobial capacity. Two-way analysis of variance (ANOVA) was performed.

RESULTS

In fresh milk, counts of C. sakazakii were reduced by 47.26% (SD = 6.74) compared to controls. In treated milk, reductions were: refrigeration at 4°C for 72 hr (M = 33.84, SD = 13.84), freezing at -20°C for 1, 2, and 3 months (M = 40.31, SD = 9.10; M = 35.96, SD = 9.39; M = 26.20, SD = 13.55, respectively), Holder pasteurization (M = 23.56, SD = 15.61), and human milk bank treatment with (M = 14.37, SD = 18.02) and without bovine fortifier (M = 3.70, SD = 23.83). There were significant differences (p < .05) between fresh and treated milk.

CONCLUSIONS

Human milk has antimicrobial capacity against C. sakazakii. However, its capacity is negatively influenced by common preservation and hygienization methods. Milk should be stored refrigerated for a maximum of 72 hr or frozen for a short period of time.

Study of the phenolic compound profile and antioxidant activity of human milk from Spanish women at different stages of lactation: A comparison with infant formulas

Human milk (HM) has been proven to have important and essential antioxidant properties to counteract infant susceptibility to oxidative stress. Phenolic compounds are secondary metabolites which come from plants and are potent natural antioxidants. The ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method used in the present study allowed the quantification of 26 phenolic compounds (ten hydroxybenzoic acids, seven hydroxycinnamic acids, four flavonoids, three hydroxybenzaldehydes and two other polyphenols) in HM samples at different stages of lactation (colostrum, transitional milk and mature milk) and infant formulas (IF). Many of the phenolic compounds identified have been reported to be present in HM for the first time. The total phenolic compound content (TPC) was quantified using the Folin assay and the antioxidant activity (AC) was evaluated with the DPPH, ABTS and FRAP assays. Significant differences were evidenced between HM and IF. HM from mothers with an adherence to a Mediterranean diet contained twice as many individual phenolic compounds as infant formulas, with a higher proportion of hydroxybenzoic acids. Conversely, IF showed a higher proportion of hydroxycinnamic acids. Overall, the antioxidant activity of HM showed small variations during lactation.

Best Practices for Human Milk Collection for COVID-19 Research

In addition to providing life-giving nutrients and other substances to the breastfed infant, human milk can also represent a vehicle of pathogen transfer. As such, when an infectious disease outbreak, epidemic, or pandemic occurs-particularly when it is associated with a novel pathogen-the question will naturally arise as to whether the pathogen can be transmitted through breastfeeding. Until high-quality data are generated to answer this question, abandonment of breastfeeding due to uncertainty can result. The COVID-19 pandemic, which was in full swing at the time this document was written, is an excellent example of this scenario. During these times of uncertainty, it is critical for investigators conducting research to assess the possible transmission of pathogens through milk, whether by transfer through the mammary gland or contamination from respiratory droplets, skin, breast pumps, and milk containers, and/or close contact between mother and infant. To promote the most rigorous science, it is critical to outline optimal methods for milk collection, handling, storage, and analysis in these situations, and investigators should openly share their methods in published materials. Otherwise, the risks of inconsistent test results from preanalytical and analytical variation, false positives, and false negatives are unacceptably high and the ability to provide public health guidance poor. In this study, we provide "best practices" for collecting human milk samples for COVID-19 research with the intention that this will also be a useful guide for future pandemics.

Influence of Maternal Age and Gestational Age on Breast Milk Antioxidants During the First Month of Lactation

Breast milk (BM) is beneficial due to its content in a wide range of different antioxidants, particularly relevant for preterm infants, who are at higher risk of oxidative stress. We hypothesize that BM antioxidants are adapted to gestational age and are negatively influenced by maternal age. Fifty breastfeeding women from two hospitals (Madrid, Spain) provided BM samples at days 7, 14 and 28 of lactation to assess total antioxidant capacity (ABTS), thiol groups, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase activities, lipid peroxidation (malondialdehyde, MDA + 4-Hydroxy-Trans-2-Nonenal, HNE), protein oxidation (carbonyl groups) (spectrophotometry) and melatonin (ELISA). Mixed random-effects linear regression models were used to study the influence of maternal and gestational ages on BM antioxidants, adjusted by days of lactation. Regression models evidenced a negative association between maternal age and BM melatonin levels (β = -7.4 ± 2.5; p-value = 0.005); and a negative association between gestational age and BM total antioxidant capacity (β = -0.008 ± 0.003; p-value = 0.006), SOD activity (β = -0.002 ± 0.001; p-value = 0.043) and protein oxidation (β = -0.22 ± 0.07; p-value = 0.001). In conclusion, BM antioxidants are adapted to gestational age providing higher levels to infants with lower degree of maturation; maternal ageing has a negative influence on melatonin, a key antioxidant hormone.

Relationship between Fatty Acids Composition/Antioxidant Potential of Breast Milk and Maternal Diet: Comparison with Infant Formulas

The fatty acid composition of human breast milk is relevant for the energy, immunity and eicosanoid production in infants. Additionally, the antioxidant properties of foods are essential for human health. Therefore, in the present study we aimed to investigate the relationship between maternal diet and fatty acids composition as well as the antioxidant potential of breast milk from donors to human milk bank of Perugia's hospital, Italy. Results were compared with infant formulas. We observed increased levels of total fatty acids and, in particular, saturated and monounsaturated fatty acids in milk from mothers fed on a vegetable and fruit-rich diet compared with a Mediterranean diet. In the same milk, a reduced antioxidant potential was found. All infant formulas resulted in richer total fatty acid content than human breast milk. Only some formulas were qualitatively similar to breast milk. Of note, the antioxidant potential of the formulas was higher or lower than the human milk with the exception of one sample. The antioxidant potential of four formulas was very high. Dietary supplementation with antioxidants has been shown to have a teratogenic effect and to increase the formation of metastases in adult. There are no data on the effects of excess antioxidants in the infants, but the possibility that they can be harmful cannot be excluded.

A randomized controlled trial protocol comparing the feeds of fresh versus frozen mother's own milk for preterm infants in the NICU

Background

Necrotizing enterocolitis (NEC) is the leading cause of death among preterm infants born at < 30 weeks’ gestation. The incidence of NEC is reduced when infants are fed human milk. However, in many neonatal intensive care units (NICUs), it is standard practice to freeze and/or pasteurize human milk, which deactivates bioactive components that may offer additional protective benefits. Indeed, our pilot study showed that one feed of fresh mother’s own milk per day was safe, feasible, and can reduce morbidity in preterm infants. To further evaluate the benefits of fresh human milk in the NICU, a randomized controlled trial is needed.

Methods

Our prospective multicenter, double-blinded, randomized, controlled trial will include infants born at < 30 weeks’ gestation and admitted to one of 29 tertiary NICUs in China. Infants in the intervention (fresh human milk) group (n = 1549) will receive at least two feeds of fresh human milk (i.e., within 4 h of expression) per day from the time of enrollment until 32 weeks’ corrected age or discharge to home. Infants in the control group (n = 1549) will receive previously frozen human milk following the current standard protocols. Following informed consent, enrolled infants will be randomly allocated to the control or fresh human milk groups. The primary outcome is the composite outcome mortality or NEC ≥ stage 2 at 32 weeks’ corrected age, and the secondary outcomes are mortality, NEC ≥ stage 2, NEC needing surgery, late-onset sepsis, retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), weight gain, change in weight, increase in length, increase in head circumference, time to full enteral feeds, and finally, the number and type of critical incident reports, including feeding errors.

Discussion

Our double-blinded, randomized, controlled trial aims to examine whether fresh human milk can improve infant outcomes. The results of this study will impact both Chinese and international medical practice and feeding policy for preterm infants. In addition, data from our study will inform changes in health policy in NICUs across China, such that mothers are encouraged to enter the NICU and express fresh milk for their infants.

Trial registration

Chinese Clinical Trial Registry; #ChiCTR1900020577; registered January 1, 2019; http://www.chictr.org.cn/showprojen.aspx?proj=34276

Impact of Donor Human Milk in the Preterm Very Low Birth Weight Gut Transcriptome Profile by Use of Exfoliated Intestinal Cells

Background: Own mother’s milk (OMM) is the optimal nutrition for preterm infants. However, pasteurized donor human milk (DHM) is a valid alternative. We explored the differences of the transcriptome in exfoliated epithelial intestinal cells (EEIC) of preterm infants receiving full feed with OMM or DHM. Methods: The prospective observational study included preterm infants ≤ 32 weeks’ gestation and/or ≤1500 g birthweight. Total RNA from EEIC were processed for genome-wide expression analysis. Results: Principal component analysis and unsupervised hierarchical clustering analysis revealed two clustered groups corresponding to the OMM and DHM groups that showed differences in the gene expression profile in 1629 transcripts. The OMM group overexpressed lactalbumin alpha gene (LALBA), Cytochrome C oxidase subunit I gene (COX1) and caseins kappa gene (CSN3), beta gene (CSN2) and alpha gene (CSN1S1) and underexpressed Neutrophil Cytosolic Factor 1 gene (NCF1) compared to the DHM group. Conclusions: The transcriptomic analysis of EEIC showed that OMM induced a differential expression of specific genes that may contribute to a more efficient response to a pro-oxidant challenge early in the postnatal period when preterm infants are at a higher risk of oxidative stress. The use of OMM should be strongly promoted in preterm infants.

The effects of storage conditions on long-chain polyunsaturated fatty acids, lipid mediators, and antioxidants in donor human milk - A review

Donor human milk (DHM) is the recommended alternative, if maternal milk is unavailable. However, current human milk banking practices may negatively affect the nutritional quality of DHM. This review summarises the effects of these practices on polyunsaturated fatty acids, lipid mediators and antioxidants of human milk. Overall, there is considerable variation in the reported effects, and further research is needed, particularly with lipid mediators and antioxidants. However, to preserve nutritional quality, DHM should be protected from light exposure and storage at 4 °C minimised, to prevent decreases in vitamin C and endocannabinoids and increases in free fatty acids and lipid peroxidation products. Storage at -20 °C prior to pasteurisation should also be minimised, to prevent free fatty increases and total fat and endocannabinoid decreases. Storage ≤-70 °C is preferable wherever possible, although post-pasteurisation storage at -20 °C for three months appears safe for free fatty acids, lipid peroxidation products, and total fat content.

A Review of Bioactive Factors in Human Breastmilk: A Focus on Prematurity

Preterm birth is an increasing worldwide problem. Prematurity is the second most common cause of death in children under 5 years of age. It is associated with a higher risk of several pathologies in the perinatal period and adulthood. Maternal milk, a complex fluid with several bioactive factors, is the best option for the newborn. Its dynamic composition is influenced by diverse factors such as maternal age, lactation period, and health status. The aim of the present review is to summarize the current knowledge regarding some bioactive factors present in breastmilk, namely antioxidants, growth factors, adipokines, and cytokines, paying specific attention to prematurity. The revised literature reveals that the highest levels of these bioactive factors are found in the colostrum and they decrease along the lactation period; bioactive factors are found in higher levels in preterm as compared to full-term milk, they are lacking in formula milk, and decreased in donated milk. However, there are still some gaps and inconclusive data, and further research in this field is needed. Given the fact that many preterm mothers are unable to complete breastfeeding, new information could be important to develop infant supplements that best match preterm human milk.