Human Milk*

Human milk oligosaccharide secretion dynamics during breastfeeding and its antimicrobial role: A systematic review

BACKGROUND

Human milk oligosaccharides (HMOs) are bioactive components of breast milk with diverse health benefits, including shaping the gut microbiota, modulating the immune system, and protecting against infections. HMOs exhibit dynamic secretion patterns during lactation, influenced by maternal genetics and environmental factors. Their direct and indirect antimicrobial properties have garnered significant research interest. However, a comprehensive understanding of the secretion dynamics of HMOs and their correlation with antimicrobial efficacy remains underexplored.

AIM

To synthesize current evidence on the secretion dynamics of HMOs during lactation and evaluate their antimicrobial roles against bacterial, viral, and protozoal pathogens.

METHODS

A systematic search of PubMed, Scopus, Web of Science, and Cochrane Library focused on studies investigating natural and synthetic HMOs, their secretion dynamics, and antimicrobial properties. Studies involving human, animal, and in vitro models were included. Data on HMO composition, temporal secretion patterns, and mechanisms of antimicrobial action were extracted. Quality assessment was performed using validated tools appropriate for study design.

RESULTS

A total of 44 studies were included, encompassing human, animal, and in vitro research. HMOs exhibited dynamic secretion patterns, with 2′-fucosyllactose (2′-FL) and lacto-N-tetraose peaking in early lactation and declining over time, while 3-fucosyllactose (3-FL) increased during later stages. HMOs demonstrated significant antimicrobial properties through pathogen adhesion inhibition, biofilm disruption, and enzymatic activity impairment. Synthetic HMOs, including bioengineered 2′-FL and 3-FL, were structurally and functionally comparable to natural HMOs, effectively inhibiting pathogens such as Pseudomonas aeruginosa , Escherichia coli , and Campylobacter jejuni . Additionally, HMOs exhibited synergistic effects with antibiotics, enhancing their efficacy against resistant pathogens.

CONCLUSION

HMOs are vital in antimicrobial defense, supporting infant health by targeting various pathogens. Both natural and synthetic HMOs hold significant potential for therapeutic applications, particularly in infant nutrition and as adjuncts to antibiotics. Further research, including clinical trials, is essential to address gaps in knowledge, validate findings, and explore the broader applicability of HMOs in improving maternal and neonatal health.

Increased Colostral Concentration of Macrophage Migration Inhibitory Factor in Mothers with Premature Rupture of Membranes

Objective: The colostrum contains macrophage migration inhibitory factor (MIF), which plays an important role in protecting newborns from infections. As such, colostrum may be specifically important to prevent early onset neonatal sepsis among neonates born after premature rupture of membranes (PROM). However, the effect of PROM on the colostral MIF concentration has not been previously described. The aim of this study is to compare the concentration of MIF in the colostrum of mothers with and without PROM. Methods: The study group consisted of 44 women, 22 of whom had PROM. Colostrum was expressed and collected within 72 hours of birth. MIF concentration was measured using the enzyme-linked immunosorbent assay method and compared between mothers with and without PROM. Results: There were no differences between the two groups (PROM group n = 22, control group n = 22) with regard to the age of mothers, mode of delivery, neonatal gestational age, birth weight, and sex of the infants (p > 0.05). The colostral MIF concentration was significantly higher among mothers with than without PROM (p = 0.0001). There was a positive and significant correlation between the colostral MIF concentration and PROM duration (r = 0.314, p = 0.038). Conclusions: PROM was associated with a higher colostral MIF concentration, with this concentration being positively correlated with the duration of PROM. This increased concentration may be important in offering these neonates additional protection against early onset infections, which is a risk associated with PROM.

Effect of Oropharyngeal Administration of Colostrum in Premature Newborns ≤32 Weeks of Gestation on the Immune Response and Neonatal Morbidity: A Double-Blind Randomized Clinical Trial

INTRODUCTION

The mother's colostrum carries immunological components, such as cytokines and immunoglobulins (Igs), derived from the maternal circulation with bacteriostatic properties.

OBJECTIVE

The objective of this study was to evaluate the effect of oropharyngeal administration of colostrum (OPAC) vs. placebo in the first 4 days of life in premature newborns ≤32 weeks of gestation on serum Ig concentration, neonatal morbidity, and total days of hospitalization.

HYPOTHESIS

The OPAC increases serum Igs and decreases morbidity and total days of hospitalization.

MATERIALS AND METHODS

A double-blind randomized controlled trial was carried out. Participants were randomly assigned to one of the two groups, namely, group 1: placebo (P) (n = 50) and group 2: colostrum (C) (n = 46). A blood sample was obtained at baseline and 7 and 28 days of life to quantify immunoglobulin G (IgG), immunoglobulin A (IgA), and IgM. Results: The C group showed an increase in serum IgA on day 28 expressed as median and [interquartile range]; C: 25 [12-35] vs. P: 11 [8-18], p < 0.001. There were no significant differences in neonatal morbidity. Newborns in the colostrum group showed the completed enteral feeding earlier (days), C: 13.9 ± 7 vs. P: 17.4 ± 8.4, p < 0.04; they reached the birth weight earlier, C: 10.9 ± 2.8 vs. P: 12.9 ± 4, p < 0.01, and had less days of hospitalization, C: 60.2 ± 33.8 vs. P: 77.2 ± 47.3, p < 0.04. Neonatal mortality was lower in the colostrum group than the placebo group 0% vs. 12%, respectively, without a statistical difference (p = 0.06).

CONCLUSION

In premature newborns ≤32 weeks of gestation, the OPAC within 4 days after birth increases serum IgA concentration at day 28 compared to placebo. Similarly, OPAC decreased the days to complete enteral feeding and reach the birth weight and total days of hospitalization.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/ct2/show/NCT03578341], identifier: [NCT03578341].