Evaluation of Fetal Intestinal Cell Growth and Antimicrobial Biofunctionalities of Donor Human Milk After Preparative Processes

Prenatal SARS-CoV-2 infection alters postpartum human milk-derived extracellular vesicles

Human milk-derived extracellular vesicles (HMEVs) are crucial functional components in breast milk, contributing to infant health and development. Maternal conditions could affect HMEV cargos; however, the impact of SARS-CoV-2 infection on HMEVs remains unknown. This study evaluated the influence of SARS-CoV-2 infection during pregnancy on postpartum HMEV molecules. Milk samples (9 prenatal SARS-CoV-2 vs. 9 controls) were retrieved from the IMPRINT birth cohort. After defatting and casein micelle disaggregation, 1 mL milk was subjected to a sequential process of centrifugation, ultrafiltration, and qEV-size exclusion chromatography. Particle and protein characterizations were performed following the MISEV2018 guidelines. EV lysates were analyzed through proteomics and miRNA sequencing, while the intact EVs were biotinylated for surfaceomic analysis. Multi-Omics was employed to predict HMEV functions associated with prenatal SARS-CoV-2 infection. Demographic data between the prenatal SARS-CoV-2 and control groups were similar. The median duration from maternal SARS-CoV-2 test positivity to milk collection was 3 months (range: 1-6 months). Transmission electron microscopy showed the cup-shaped nanoparticles. Nanoparticle tracking analysis demonstrated particle diameters of <200 nm and yields of >1e11 particles from 1 mL milk. Western immunoblots detected ALIX, CD9 and HSP70, supporting the presence of HMEVs in the isolates. Thousands of HMEV cargos and hundreds of surface proteins were identified and compared. Multi-Omics predicted that mothers with prenatal SARS-CoV-2 infection produced HMEVs with enhanced functionalities involving metabolic reprogramming and mucosal tissue development, while mitigating inflammation and lower EV transmigration potential. Our findings suggest that SARS-CoV-2 infection during pregnancy boosts mucosal site-specific functions of HMEVs, potentially protecting infants against viral infections. Further prospective studies should be pursued to reevaluate the short- and long-term benefits of breastfeeding in the post-COVID era.

Nurse-Driven Interventions for Improving ELBW Neurodevelopmental Outcomes

Survival rates for extremely low-birth-weight (ELBW) infants are improving as neurodevelopmental impairment (NDI) rates stay stable, thereby increasing the overall number of infants with NDI. Although there are many determinants of NDI in this population, nutritional factors are of interest because they are readily modifiable in the clinical setting. Nurses can influence nutritional factors such as improving access to human milk feeding, using growth monitoring, establishing feeding policies, implementing oral care with colostrum, facilitating kangaroo care, and providing lactation education for the mother. All of these measures assist in leading to a decrease in NDI rates among ELBW infants.

Human Milk Extracellular Vesicles: A Biological System with Clinical Implications

The consumption of human milk by a breastfeeding infant is associated with positive health outcomes, including lower risk of diarrheal disease, respiratory disease, otitis media, and in later life, less risk of chronic disease. These benefits may be mediated by antibodies, glycoproteins, glycolipids, oligosaccharides, and leukocytes. More recently, human milk extracellular vesicles (hMEVs) have been identified. HMEVs contain functional cargos, i.e., miRNAs and proteins, that may transmit information from the mother to promote infant growth and development. Maternal health conditions can influence hMEV composition. This review summarizes hMEV biogenesis and functional contents, reviews the functional evidence of hMEVs in the maternal–infant health relationship, and discusses challenges and opportunities in hMEV research.

HMP-S7 Is a Novel Anti-Leukemic Peptide Discovered from Human Milk

Chemotherapy in childhood leukemia is associated with late morbidity in leukemic survivors, while certain patient subsets are relatively resistant to standard chemotherapy. It is therefore important to identify new agents with sensitivity and selectivity towards leukemic cells, while having less systemic toxicity. Peptide-based therapeutics has gained a great deal of attention during the last few years. Here, we used an integrative workflow combining mass spectrometric peptide library construction, in silico anticancer peptide screening, and in vitro leukemic cell studies to discover a novel anti-leukemic peptide having 3+ charges and an alpha helical structure, namely HMP-S7, from human breast milk. HMP-S7 showed cytotoxic activity against four distinct leukemic cell lines in a dose-dependent manner but had no effect on solid malignancies or representative normal cells. HMP-S7 induced leukemic cell death by penetrating the plasma membrane to enter the cytoplasm and cause the leakage of lactate dehydrogenase, thus acting in a membranolytic manner. Importantly, HMP-S7 exhibited anti-leukemic effects against patient-derived leukemic cells ex vivo. In conclusion, HMP-S7 is a selective anti-leukemic peptide with promise, which requires further validation in preclinical and clinical studies.

Midwifery and Nursing Strategies to protect against COVID-19 During the Third Trimester of Pregnancy

Objective

The rapid pace of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic (COVID-19) presents significant challenges to midwives and nurses. This study aimed to explore midwifery and nursing interventions to limit the transmission of COVID-19 among women in their third trimester of pregnancy, to reduce the incidence of nosocomial infection and promote safety of care for women and their infants.

Method

We completed a retrospective review of medical records from 35 women in their third trimester of pregnancy with SARS-CoV-2, admitted to one hospital in Wuhan, China in January and February 2020. We investigated the clinical characteristics of the COVID-19 infection in pregnancy, and the individualized midwifery and nursing care offered, including environmental protection, prevention of nosocomial infection, maternal observations, monitoring of signs and symptoms of COVID-19, and psychological care.

Result

Thirty-one women had a caesarean section, and four had vaginal births. Retrospective analysis of midwifery and nursing strategies implemented to care for these women showed no maternal complications or nosocomial infections.

Conclusions and implications for practice

The care strategies we implemented could prevent complications and nosocomial infection in the third trimester of pregnancy, thus ensuring the safety of women and their infants. Further research needs to determine treatment priorities for women infected with COVID-19 during pregnancy and the postnatal period.

Effects of Refrigerated and Frozen Storage on Holder-Pasteurized Donor Human Milk: A Systematic Review

BACKGROUND

Pasteurized donor human milk (PDHM) is the recommended feeding alternative for preterm infants when mother's own milk is not available. Use of PDHM in United States neonatal hospitals is increasing, although guidelines for the refrigerated and frozen storage are limited.

OBJECTIVE

We aimed to review the current evidence for the storage of Holder PDHM (HPDHM) under refrigerated and frozen storage conditions.

METHODS

A systematic review of the literature was conducted for studies published between 1985 and May 2018. Studies were included if they studied the storage of Holder-pasteurized human milk under refrigerated or frozen storage conditions.

RESULTS

Fourteen studies met the inclusion criteria. Five studies addressed refrigerated storage and nine studies addressed frozen storage. There was little overlap in the outcomes measured or the analytical methods employed. There was concordance in three studies reporting no microbial growth over 4-9 days of refrigerated storage, and in five studies reporting a reduction in fat during 1-8 months of frozen storage. Only one study assessed the storage of HPDHM that had been fortified.

CONCLUSIONS

Long-term refrigerated and frozen storage of HPDHM affects some components in milk more than others. While there is evidence of microbial purity during four or more days of refrigerated storage in clinical conditions, there is limited research on the impact of macro and micronutrients, or the impact of fortifiers. More research is needed in these areas.

Fetal Intestinal Cell Growth as a Measure of the Comparative Biofunctionality of Human Milk and Infant Formulas: An In Vitro Study

BACKGROUND

Infant formulas are produced to resemble human milk (HM) and to provide adequate energy and appropriate nutritional components for suitability of infant growth and development, some of which are customized for specific medical conditions. However, it has remained unclear whether formulas contain any biofunctionality equivalent to HM, particularly fetal intestinal cell growth promotion.

OBJECTIVE

To evaluate the biofunctionality in HM and various formulas by using an in vitro fetal intestinal cell growth assay.

MATERIALS AND METHODS

Nine specimens of HM collected from 9 milk donors and 16 formulas consisting of 5 regular formulas (RFs), 2 preterm formulas (PFs), 2 partial hydrolysate formulas (PHFs), 3 extensive hydrolysate formulas (EHFs), 2 amino acid formulas (AAFs), and 2 soy protein formulas (SPFs) were included. Fetal intestinal cell growth assay was performed in six replicates per milk specimen. Biofunctionality of HM digest (HMD) derived from in vitro tryptic digestion of HM was also examined. Statistical analysis was performed by ANOVA with post-hoc Tukey's Honestly Significant Difference test.

RESULTS

The fetal intestinal cell growth-promoting activity of HM and formula groups were sorted from the highest as follows: HM, 192.8% ± 16.7%; AAF, 153.5% ± 17.8%; EHF, 149.4% ± 12.5%; RF, 123.5% ± 14.2%; PHF, 111.2% ± 17.9%; PF, 110.3% ± 8.2%; and SPF, 109.3% ± 17.3%. Statistical analysis showed that growth promotion of HM was significantly higher than that of all examined formulas (p < 0.0001). Among formulas, EHF and AAF showed greater growth-promoting activity than the others (p < 0.0001). HM and HMD had a comparable growth-promoting effect on fetal intestinal cells (198.5% ± 27.9% versus 191.2% ± 17.9%, p = 0.724), supporting the potential impact of HM biofunctionality under physiologic gastrointestinal digestion.

CONCLUSIONS

Our data suggested that formulas are not equivalent to HM in respect of fetal intestinal cell growth biofunctionality. Despite having less activity than HM, EHF and AAF exhibited considerable levels of growth-promoting effect that may have clinical implications, especially when HM is unavailable.