Role of Human Milk Bioactives on Infants' Gut and Immune Health

Early life gut microbiome and its impact on childhood health and chronic conditions

The development of the gut microbiome is crucial to human health, particularly during the first three years of life. Given its role in immune development, disturbances in the establishment process of the gut microbiome may have long term consequences. This review summarizes evidence for these claims, highlighting compositional changes of the gut microbiome during this critical period of life as well as factors that affect gut microbiome development. Based on human and animal data, we conclude that the early-life microbiome is a determinant of long-term health, impacting physiological, metabolic, and immune processes. The early-life gut microbiome field faces challenges. Some of these challenges are technical, such as lack of standardized stool collection protocols, inconsistent DNA extraction methods, and outdated sequencing technologies. Other challenges are methodological: small sample sizes, lack of longitudinal studies, and poor control of confounding variables. To address these limitations, we advocate for more robust research methodologies to better understand the microbiome's role in health and disease. Improved methods will lead to more reliable microbiome studies and a deeper understanding of its impact on health outcomes.

Emerging insights of Staphylococcus spp. in human mastitis

Human mastitis represents a prevalent and intricate condition that significantly challenges breastfeeding women, often exacerbated by pathogenic bacteria such as Staphylococcus aureus. A deep understanding of the interplay between human mastitis, the breast milk microbiome, and causative agents is imperative. This understanding must focus on the bacterium's virulence and resistance genes, which critically influence the severity and persistence of mastitis. Current methods for detecting these genes, including Polymerase Chain Reaction (PCR), 16S rRNA gene sequencing, shotgun metagenomic sequencing, multiplex PCR, whole genome sequencing (WGS), loop-mediated isothermal amplification (LAMP), CRISPR-based assays, and microarray technology, are vital in elucidating bacterial pathogenicity and resistance profiles. However, advanced attention is required to refine diagnostic techniques, enabling earlier detection and more effective therapeutic approaches for human mastitis. The involvement of Staphylococcus aureus in human infection should be a prime focus, especially in women's health, which deals directly with neonates. Essential virulence genes in Staphylococcus species are instrumental in infection mechanisms and antibiotic resistance, serving as potential targets for personalized treatments. Thus, this review focuses on Staphylococcusaureus-induced mastitis, examining its virulence factors and detection techniques to advance diagnostic and therapeutic strategies.

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.

Intestinal microbiota and respiratory system diseases: Relationships with three common respiratory virus infections

In recent years, the role of the intestinal microbiota in regulating host health and immune balance has attracted widespread attention. This study provides an in-depth analysis of the close relationship between the intestinal microbiota and respiratory system diseases, with a focus on three common respiratory virus infections, including respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and influenza virus. The research indicates that during RSV infection, there is a significant decrease in intestinal microbial diversity, suggesting the impact of the virus on the intestinal ecosystem. In SARS-CoV-2 infection, there are evident alterations in the intestinal microbiota, which are positively correlated with the severity of the disease. Similarly, influenza virus infection is associated with dysbiosis of the intestinal microbiota, and studies have shown that the application of specific probiotics exhibits beneficial effects against influenza virus infection. Further research indicates that the intestinal microbiota exerts a wide and profound impact on the occurrence and development of respiratory system diseases through various mechanisms, including modulation of the immune system and production of short-chain fatty acids (SCFAs). This article comprehensively analyzes these research advances, providing new perspectives and potential strategies for the prevention and treatment of future respiratory system diseases. This study not only deepens our understanding of the relationship between the intestinal microbiota and respiratory system diseases but also offers valuable insights for further exploring the role of host-microbiota interactions in the development of diseases.

Influence of fatty acid distribution on lipid metabolism and cognitive development in first-weaned mice

There are significant structural differences between breast milk fat and the fat found in existing infant formulas, and these differences may partly explain the observed variations in growth and development between breastfed and formula-fed infants. This study used mice compared three groups: a control group (mixed vegetable oil), an OPO group (vegetable oil added with OPO), and a human milk fat substitute (HMFS) group formulated to match the fatty acid composition of breast milk. Compared to the control group and OPO group, HMFS-fed mice exhibited reduced body fat content and improved cognitive abilities. Lipidomics studies revealed that these differences in HMFS mice were associated with downregulation of hepatic glycerolipids and upregulation of glycerophospholipids and sphingolipids, facilitating the delivery of long-chain polyunsaturated fatty acids to the brain. Molecular investigations confirmed that HMFS reduces body fat accumulation by inhibiting endogenous fatty acid synthesis and promoting fatty acid β-oxidation, while changes in hepatic lipid profiles result from lipid molecule synthesis and interconversion. Metataxonomic studies demonstrated that HMFS reshaped the gut microbiota, including upregulating Akkermansia and downregulating Desulfovibrio and the Firmicutes/Bacteroidetes ratio, with strong correlations observed between the change of gut microbiota and responded lipids in liver. Overall, the breast milk's unique fatty acid distribution promotes organismal growth by modulating hepatic lipid metabolism, systemic lipid circulation, and gut microbiota. These findings underscore the nutritional benefits of breast milk fat structure and provide insights for the development of next-generation infant formulas.

Human Milk Oligosaccharide Lacto-N-Neotetraose Promotes Gut Microbiota Recovery in the Context of Antibiotic-Induced Dysbiosis

Human milk oligosaccharides (HMOs) may shape intestinal homeostasis, although the optimal form of HMOs to restore the gut microbiota in antibiotic-induced dysbiosis remains unclear. Here, we found that HMOs with various structures modulate microbial communities differently after antibiotic exposure. Lacto-N-neotetraose (LNnT) better promotes the recovery of intestinal microbiota (chiefly Lactobacillus) and increases the level of Bifidobacterium compared to 3'-sialyllactose, 2'-fucosyllactose, and the mixture. Additionally, LNnT decreases the potential pathogenic bacteria Klebsiella level and the microbial dysbiosis index. Although supplementation with LNnT does not decrease the Clostridioides difficile burden or alleviate the decline in the fecal numbers of Lactobacillus and Bifidobacterium after C. difficile infection (CDI), LNnT attenuates intestinal epithelial damage, decreases inflammatory status, and alters metabolome profiles after CDI. Collectively, LNnT may function as a promising prebiotic to promote gut microbiota recovery in the context of antibiotic-induced dysbiosis.

Glycosyltransferases: glycoengineers in human milk oligosaccharide synthesis and manufacturing

Human milk oligosaccharides (HMOs) are a diverse group of complex carbohydrates that play crucial roles in infant health, promoting a beneficial gut microbiota, modulating immune responses, and protecting against pathogens. Central to the synthesis of HMOs are glycosyltransferases, a specialized class of enzymes that catalyse the transfer of sugar moieties to form the complex glycan structures characteristic of HMOs. This review provides an in-depth analysis of glycosyltransferases, beginning with their classification based on structural and functional characteristics. The catalytic activity of these enzymes is explored, highlighting the mechanisms by which they facilitate the precise addition of monosaccharides in HMO biosynthesis. Structural insights into glycosyltransferases are also discussed, shedding light on how their conformational features enable specific glycosidic bond formations. This review maps out the key biosynthetic pathways involved in HMO production, including the synthesis of lactose, and subsequent fucosylation and sialylation processes, all of which are intricately regulated by glycosyltransferases. Industrial methods for HMO synthesis, including chemical, enzymatic, and microbial approaches, are examined, emphasizing the role of glycosyltransferases in these processes. Finally, the review discusses future directions in glycosyltransferase research, particularly in enhancing the efficiency of HMO synthesis and developing advanced analytical techniques to better understand the structural complexity and biological functions of HMOs.

Macronutrient concentrations in human milk beyond the first half year of lactation: a cohort study

OBJECTIVE

Human milk composition is dynamic. While extensive research has focused on its macronutrient concentrations during the first 6 months of lactation, limited research exists for extended lactation periods. This study aims to examine the nutritional composition of human milk during these longer lactation phases.

DESIGN

A retrospective longitudinal cohort study performed within the National Dutch Human Milk Bank.

PARTICIPANTS

We selected donors who had provided milk donations at least once after the 6-month postpartum mark.

MAIN OUTCOME MEASURES

The Miris Human Milk Analyser was used to analyse macronutrient concentrations in the milk samples. Linear mixed models were used for longitudinal analysis of these concentrations, factoring in time variables established for six sequential lactation periods.

RESULTS

We analysed 820 milk samples from 86 women, collected between 5 weeks and 28 months postpartum. Initially, milk protein concentrations dropped over the first 8 months of lactation (diff = -0.19 g/dL, p<0.001) and stabilised between 8 and 18 months before increasing again by 0.21 (95% CI 0.06-0.21) g/dL. Carbohydrate concentrations remained steady throughout the study period. Fat concentrations were stable for the first 8 months but saw an increase afterwards. Post 18 months, the fat content saw a rise of 1.90 (95% CI 1.59-2.21) g/dL. The caloric density mirrored the pattern of the fat concentrations.

CONCLUSION

The nutritional content of human milk does not decrease after 6 months of lactation. Therefore, human milk banks may accept donations from mothers up to 2 years post-birth.

Evaluation of Ultra-High Pressure Homogenization Treatments to Ensure the Microbiological Safety and Immunoglobulin Preservation in Donor Human Milk

Most donor human milk (HM) banks use Holder pasteurization (HoP) to ensure microbiological safety, although it can degrade essential bioactive factors for newborns. This study evaluates the innovative ultra-high-pressure homogenization (UHPH) technology as a potential alternative. Listeria innocua, Staphylococcus carnosus, Franconibacter helveticus (formerly named Cronobacter helveticus) and Escherichia coli strains were used as surrogates for common HM pathogens according to European Milk Bank Association (EMBA) guidelines, to evaluate the efficacy of new technologies. A reconstituted powder milk formula inoculated with these strains was used to determine the most efficient conditions (those to achieve a lethality of ≥5 Log), applying treatments from 150 to 300 MPa. These treatments were later validated using inoculated HM with the same strains. Immunoglobulin (sIgA, IgG, IgM) retention was also evaluated and compared with HoP. Results showed that UHPH treatments at 200 MPa achieved a lethality > 5 Log for all strains, except for St. carnosus, which required 250 MPa for complete inactivation in HM. Unlike HoP, UHPH at 200 and 250 MPa did not significantly reduce the basal concentration of sIgA, IgG, or IgM compared with raw HM. These findings suggest UHPH as a promising alternative to HoP, maintaining both microbiological safety and immunological quality.

Campylobacter jejuni resistance to human milk involves the acyl carrier protein AcpP

Campylobacter jejuni is a common foodborne pathogen worldwide that is associated with high rates of morbidity and mortality among infants in low- to middle-income countries (LMICs). Human milk provides infants with an important source of nutrients and contains antimicrobial components for protection against infection. However, recent studies, including our own, have found significantly higher levels of Campylobacter in diarrheal stool samples collected from breastfed infants compared to non-breastfed infants in LMICs. We hypothesized that C. jejuni has unique strategies to resist the antimicrobial properties of human milk. Transcriptional profiling found human milk exposure induces genes associated with ribosomal function, iron acquisition, and amino acid utilization in C. jejuni strains 81-176 and 11168. However, unidentified proteinaceous components of human milk prevent bacterial growth. Evolving both C. jejuni isolates to survive in human milk resulted in mutations in genes encoding the acyl carrier protein (AcpP) and the major outer membrane porin (PorA). Introduction of the PorA/AcpP amino acid changes into the parental backgrounds followed by electron microscopy showed distinct membrane architectures, and the AcpP changes not only significantly improved growth in human milk, but also yielded cells surrounded with outer membrane vesicles. Analyses of the phospholipid and lipooligosaccharide (LOS) compositions suggest an imbalance in acyl chain distributions. For strain 11168, these changes protect both evolved and 11168∆acpPG33R strains from bacteriophage infection and polymyxin killing. Taken together, this study provides insights into how C. jejuni may evolve to resist the bactericidal activity of human milk and flourish in the hostile environment of the gastrointestinal tract.

IMPORTANCE

In this study, we evolved C. jejuni strains which can grow in the presence of human milk and found that cell membrane alterations may be involved in resistance to the antimicrobial properties of human milk. These bacterial membrane changes are predominantly linked to amino acid substitutions within the acyl carrier protein, AcpP, although other bacterial components, including PorA, are likely involved. This study provides some insights into possible strategies for C. jejuni survival and propagation in the gastrointestinal tract of breastfed infants.

Exosomes in Breast Milk: Their Impact on the Intestinal Microbiota of the Newborn and Therapeutic Perspectives for High-Risk Neonates

Breast milk exosomes are essential for the nutrition and immune development of the newborn. These 30-150 nm extracellular vesicles contain microRNAs (miRNAs), mesessenger RNAS (mRNA)s, proteins and lipids that facilitate cellular communication and modulate the neonatal immune system. In this article, we analyse the impact of breast milk exosomes on the intestinal microbiota of the newborn, especially in high-risk neonates such as preterm infants or neonates at risk of necrotising enterocolitis (NEC). Exosomes promote the colonisation of beneficial bacteria such as Bifidobacterium and Lactobacillus and strengthen the intestinal barrier. They also regulate the immune response, balancing defence against pathogens and tolerance to non-pathogenic antigens. This effect is key for high-risk infants, who benefit from their anti-inflammatory and preventive properties against complications such as NEC. Research points to their potential therapeutic uses in neonatal care, opening up new opportunities to improve the health of vulnerable newborns through the protective effects of breast milk exosomes.

Impact of Freezing, Storage, and Pasteurization on Nutritional Components and Redox Biomarkers in Human Milk Donations

Objective: This study evaluates the impact of various processing steps in the human milk (HM) donation chain on nutritional composition and oxidative biomarkers, specifically focusing on triacylglycerols, glucose, polyphenols, and lipid peroxides. Materials and Methods: A total of 68 HM samples were collected from the Human Milk Bank of Córdoba (Argentina) between 2022 and 2023. The effects of storage and pasteurization using the Holder method were assessed. Biochemical analyses were conducted to measure nutrient levels and oxidative markers. Statistical analyses included time-related modeling and paired t tests to evaluate the effects of storage and pasteurization, respectively. Results: Triacylglycerol levels were markedly reduced during home storage (R2 = 0.802, p = 0.0210), whereas glucose, lipid peroxides, and polyphenols remained stable (R2 < 0.3, p > 0.05). Storage at the bank did not affect these biomarkers (R2 < 0.25, p > 0.05). Pasteurization resulted in increased glucose levels (p = 0.0292) and decreased triacylglycerol levels (p = 0.0073), along with a significant reduction in lipid peroxides (p < 0.0001). Conclusions: The findings indicate that home storage conditions significantly diminish triacylglycerol levels in HM, highlighting the need for improved storage practices among donors. Pasteurization provides antioxidant benefits by reducing lipid peroxides while maintaining nutritional integrity.

Association Between Different Feeding Methods and Bronchopulmonary Dysplasia in Preterm Infants: A Retrospective Cohort Study

Background: This study examines the relationship between feeding methods during the first 2 weeks post-birth-mother's own milk (MOM), donor human milk (DHM), and formula-and the incidence of bronchopulmonary dysplasia (BPD) in preterm infants. Materials and Methods: A retrospective cohort study was conducted on preterm infants (<32 weeks gestation or <1,500 g birth weight) admitted to Fujian Maternal and Child Health Hospital from March 2023 to February 2024. Infants were grouped by primary feeding method within the first 2 weeks after birth, defined as MOM, DHM, or formula contributing to ≥50% of total feeding. The primary outcome was BPD incidence; the secondary outcome included necrotizing enterocolitis (NEC) stage II or higher, periventricular leukomalacia (PVL), retinopathy of prematurity (ROP), and sepsis. Results: BPD incidence was lower in the MOM and DHM groups compared with formula (22%, 16% vs. 35%; p = 0.03). Adjusted odds ratios for BPD were 3.35 (95% CI 1.43, 7.85) in the formula group versus MOM and 6.48 (95% CI 1.47, 28.57) versus DHM, with no significant difference between MOM and DHM. NEC incidence was also lower in MOM and DHM groups (7.15%, 9.38% vs. 20.21%; p = 0.016). No significant differences were observed in ROP, PVL, or sepsis rates. Conclusions: MOM and DHM reduce the risk of BPD and NEC in preterm infants, with DHM being as safe as MOM.

Bacillus subtilis-Derived Surfactin Alleviates Offspring Intestinal Inflammatory Injuries Through Breast Milk

BACKGROUND

Enteric and diarrheal diseases pose a significant threat to infant health, highlighting the importance of immune defenses in early life, especially maternal protection, in establishing a robust gastrointestinal environment. Surfactin, a bioactive peptide from Bacillus subtilis, has immunomodulatory properties, yet its influence on offspring via maternal gut interference is not fully understood. This study examines the effects of maternal surfactin consumption on breast milk's immunological properties and its consequent effects on neonatal intestinal health.

METHODS

Twenty-eight gravid mice were randomly categorized into two cohorts and were given surfactin or not in drinking water from one week after conception to 21 days postpartum. Cross-fostering experiments were conducted within 12 h after birth. Pups from the surfactin-supplemented dams were fostered and nursed by the control dams, while the pups from the control dams were nursed by the surfactin-supplemented dams.

RESULTS

The findings show that the pups from the surfactin-supplemented dams had increased body weight, improved intestinal morphology with longer villus and deeper crypts, the upregulation of genes related to mucins and antimicrobial peptides, and an increase in IgA+ and CD3+ T cells within the intestinal mucosa. Further, the cross-fostering experiments suggested that the pups nursed by the surfactin-supplemented dams gained more weight, had less intestinal damage, less inflammation, and lower oxidative stress levels induced by Salmonella typhimurium, indicating the immunological benefits of surfactin conveyed through breast milk. Additionally, the expression of pro-inflammatory factors, including nitric oxide, TNF-α, IL-1β, IL-6, MCP-1, and ROS, induced by LPS in the macrophages was significantly inhibited with milk from the surfactin-supplemented dam (MSD) treatment. Interestingly, the MSD treatment induced a shift in macrophage polarization from pro-inflammatory (M1-like) to anti-inflammatory (M2-like), evidenced by the decreased expression of IL-12p40 and iNOS and the increased expression of CD206, TGF-β, and Arg-1. In terms of mechanism, surfactin improved the contents of the anti-inflammatory factors IL-4, IL-10, and TGF-β in the breast milk.

CONCLUSIONS

This research contributes to understanding how maternal interference can modulate breast milk composition, influence infant gastrointestinal development and immunity, and provide nutritional strategy insights.

Challenges and Opportunities in Quantifying Bioactive Compounds in Human Breastmilk

Breastmilk is a complex biological fluid containing over a thousand bioactive proteins, lipids, cells and small molecules that provide nutrition and immunological protection for infants and children. The composition of breastmilk is unique to each individual and can also vary within individuals according to breastfeeding duration, maternal health, time of day, and other factors. As such, the composition of breastmilk can be considered a "fingerprint" that could be interrogated to identify biomarkers of breast health and disease. However, accurate quantification of bioactive components in breastmilk remains a significant challenge. Approaches such as immunoassays and mass spectrometry have been largely applied to study blood or other biological fluids and require validation and optimisation before these techniques can be used to accurately quantify bioactive compounds in breastmilk. Development of protocols specific to breastmilk should be carried out with high precision, confidence, and sensitivity. This review explores the challenges and opportunities associated with different techniques for quantification of breastmilk bioactive components.

The Neonatal Microbiome: Implications for Amyotrophic Lateral Sclerosis and Other Neurodegenerations

Most brain development occurs in the "first 1000 days", a critical period from conception to a child's second birthday. Critical brain processes that occur during this time include synaptogenesis, myelination, neural pruning, and the formation of functioning neuronal circuits. Perturbations during the first 1000 days likely contribute to later-life neurodegenerative disease, including sporadic amyotrophic lateral sclerosis (ALS). Neurodevelopment is determined by many events, including the maturation and colonization of the infant microbiome and its metabolites, specifically neurotransmitters, immune modulators, vitamins, and short-chain fatty acids. Successful microbiome maturation and gut-brain axis function depend on maternal factors (stress and exposure to toxins during pregnancy), mode of delivery, quality of the postnatal environment, diet after weaning from breast milk, and nutritional deficiencies. While the neonatal microbiome is highly plastic, it remains prone to dysbiosis which, once established, may persist into adulthood, thereby inducing the development of chronic inflammation and abnormal excitatory/inhibitory balance, resulting in neural excitation. Both are recognized as key pathophysiological processes in the development of ALS.

From Pregnancy to Breastfeeding: The Role of Maternal Exercise in Preventing Childhood Obesity

Low adherence to healthy lifestyle behaviors during pregnancy and lactation is strongly associated with a higher risk of childhood obesity. This narrative review aims to elucidate and summarize the pivotal role played by physical activity (PA) during pregnancy and breastfeeding, highlighting the potential mechanisms linking PA in these periods to the prevention of childhood obesity. Maternal exercise during pregnancy and breastfeeding significantly reduces the risk of childhood obesity by enhancing fetal metabolism, supporting healthy maternal weight management, and promoting improved breastfeeding practices. Pregnancy and the postpartum period represent critical windows for implementing preventive strategies that benefit both the mother and child. Encouraging an active lifestyle during pregnancy and breastfeeding is a vital public health strategy with extensive benefits. Healthcare professionals play a crucial role in creating supportive environments and providing tailored guidance to empower mothers to engage in regular PA. This approach not only enhances individual health outcomes but also contributes to the broader goal of fostering healthier communities.

Bidirectional Interplay Among Non-Coding RNAs, the Microbiome, and the Host During Development and Diseases

It is widely known that the dysregulation of non-coding RNAs (ncRNAs) and dysbiosis of the gut microbiome play significant roles in host development and the progression of various diseases. Emerging evidence has highlighted the bidirectional interplay between ncRNAs and the gut microbiome. This article aims to review the current understanding of the molecular mechanisms underlying the crosstalk between ncRNAs, especially microRNA (miRNA), and the gut microbiome in the context of development and diseases, such as colorectal cancer, inflammatory bowel diseases, neurological disorders, obesity, and cardiovascular disease. Ultimately, this review seeks to provide a foundation for exploring the potential roles of ncRNAs and gut microbiome interactions as biomarkers and therapeutic targets for clinical diagnosis and treatment, such as ncRNA mimics, antisense oligonucleotides, and small-molecule compounds, as well as probiotics, prebiotics, and diets.

Suckling Rat Pup Model: Do Caprine Milk Lactoferrin and Immunoglobulins Have Different Digestion and Absorption Properties from That of Human and Bovine Species?

This study aimed to investigate the digestion and absorption properties of caprine milk serum proteins in comparison to human and bovine species by using rat pups to mimic preterm infants. The results indicate that caprine lactoferrin (LTF) had a shorter retention time in the intestine and released a greater number of fragments, resembling human milk LTF more closely. In contrast, caprine immunoglobulins (Igs) were similar to bovine Igs and both exhibited a longer retention time in the intestine. For absorption, caprine Igs could be absorbed intact, which was similar to human and bovine Igs, whereas caprine LTF fragments were found in jejunum but not in plasma of rat pups. This is similar to bovine LTF but differed from human LTF as human LTF could be absorbed intact in plasma of rat pups at 20 min. In addition, the absorption rate of peptides and amino acids from caprine milk serum was similar to that of human milk serum, which was higher than that from bovine milk serum. This study aimed to enhance our understanding of the differences in bioavailability of LTF and Igs derived from caprine, human milk, and bovine milk, thereby offering guidance for selecting protein sources for premature infants.

Donor Human Milk Fat Content Is Associated with Maternal Body Mass Index

Introduction: Donor human milk is increasingly being utilized for both preterm and term infants when mother's milk is unavailable. With the rising prevalence of maternal overweight and obesity, it is crucial to evaluate the relationship between maternal body mass index and the fat and energy content of donor human milk. Objectives: To assess the impact of maternal body mass index on human milk fat content. Methods: A cross-sectional study was carried out using retrospective data from women who made their first human milk donation at ≥15 days postpartum at a human milk bank in São Paulo, Brazil, from January 2018 to December 2020. Data of sociodemographic, obstetric, health, and anthropometric measures were collected by the human milk bank staff. Milk fat and energy content were determined using the crematocrit test. Analysis of variance and multiple linear regression were used to compare means of crematocrit and fat. We determined the p-values using a test of heterogeneity and linear trend and presented the one with the lower p-value. Results: Most donors were between 25 and 35 years old, had higher education, were employed, and lived with a partner. At the time of milk donation, 40.9% of women were overweight or obese. The fat (1.09 g/dL) and energy (9.83 kcal/dL) content of human milk were higher in obese donor compared with eutrophic donors. Conclusions: The fat and energy content of human milk were associated with maternal body mass index, suggesting the potential value for selective use of high fat and high calorie donor milk for very low birthweight or premature infants.

Bovine colostrum prevents formula-induced gut microbiota dysbiosis in preterm pigs

BACKGROUND

Preterm birth and formula feeding increase the risk of necrotizing enterocolitis (NEC), a gut inflammatory disease known to be associated with gut microbiota (GM) changes in infants. Supplemental bovine colostrum may protect against formula-induced NEC via GM changes. We hypothesised that feeding colostrum before, after, or during formula feeding affects NEC sensitivity via changes to GM.

METHODS

Colonic GM (profiled by 16S ribosomal RNA gene amplicon sequencing) was compared in preterm pigs fed colostrum for 4 days, either before, after, or together with formula feeding for 4 days. Correlations between GM and gut parameters were assessed on day 5 or 9.

RESULTS

Both exclusive and partial colostrum feeding induced higher GM diversity, lower Enterococcus abundance, and improved intestinal maturation parameters (villus structure, digestive enzyme activities, permeability), relative to exclusive formula feeding (all p < 0.05). Across feeding regimens, Enterococcus abundance was inversely correlated with intestinal maturation parameters. Conversely, there was no correlation between GM changes and early NEC lesions.

CONCLUSION

Bovine colostrum inhibits formula-induced Enterococcus overgrowth and gut dysfunctions just after preterm birth but these effects are not causally linked. Optimising diet-related host responses, not GM, may be critical to prevent NEC in preterm newborn pigs and infants.

IMPACT

Supplement of bovine colostrum to formula feeding modified the gut microbiota by increasing species diversity and reducing Enterococcus abundance, while concurrently improving intestinal functions in preterm pigs. Diet-related changes to the gut microbiota were not clearly associated with development of necrotizing enterocolitis (NEC) in preterm pigs, suggesting that diet-related gut microbiota effects are not critical for diet-related NEC protection. The study highlights the potential to use bovine colostrum as a supplement to formula feeding for preterm infants lacking human milk.

Human breast milk-derived exosomes and their positive role on neonatal intestinal health

Although the role of breast milk in promoting neonatal growth and maintaining intestinal homeostasis is well established, underlying mechanisms by which it protects the intestine from damage remain to be elucidated. Human breast milk-derived exosomes (HMDEs) are newly discovered active signaling vesicles with a diameter of 30-150 nm, which are key carriers of biological information exchange between mother and child. In addition, due to their ability to cross the gastrointestinal barrier, low immunogenicity, good biocompatibility and stability, HMDEs play an important role in regulating intestinal barrier integrity in newborns. In addition, HMDEs possess specific properties that are reformable and modifiable, offering promising strategies for the prevention and treatment of neonatal intestinal diseases. However, challenges such as purification, complex content, and quality control hinder their clinical application. This paper provides a comprehensive review of the biogenesis and properties of HMDEs, their isolation and purification, composition, and effects on neonatal intestinal barrier function, and further explores their potential biomedical applications. IMPACT: Breast milk helps maintain intestinal homeostasis in newborns and can prevent diseases, especially necrotizing enterocolitis (NEC). Breast milk contains abundant exosomes, which are important carriers of maternal and infant biological information exchange. Breast milk have the advantages of low immunogenicity, good biocompatibility and good stability, which helps to maintain the integrity of the intestinal barrier. Exosomes can be modified, which is expected to provide a more effective strategy for the prevention and treatment of intestinal diseases.

In Vitro Infant Fecal Fermentation Metabolites of Osteopontin and 2'-Fucosyllactose Support Intestinal Barrier Function

In this study, we investigated the effects of infant fecal fermentation-derived metabolites of digested osteopontin (OPN) and 2'-fucosyllactose (2'-FL), either individually or in combination, on intestinal barrier function using a Caco-2/HT-29 coculture cell model. Our results suggested that the OPN/2'-FL (1:36-1:3) cofermentation metabolites improved epithelial barrier integrity by supporting the mRNA and protein expression of occludin, claudin-1, claudin-2, ZO-1, and ZO-2. All of the OPN/2'-FL treatments decreased the production of IL-1β, IL-6, and TNF-α, while the OPN/2'-FL ratio increased IL-10 production by inhibiting activation of the MyD88/IκB-α/NF-κB signaling pathway. OPN/2'-FL cofermentation altered the metabolic pathways, and the protective effect of fermentation metabolites on intestinal barrier function was related to differential metabolite expression such as short-chain fatty acids, deoxycholic acid, and 4-aminobutyric acid. Our findings provide in vitro evidence to support the application of the OPN/2'-FL combination in infant formula for the advancement of formulation functionality, including intestinal barrier function.

Fecal Microbiome and Metabolomic Profiles of Mixed-Fed Infants Are More Similar to Formula-Fed than Breastfed Infants

Many infants consume both human milk and infant formula (mixed-fed); however, few studies have investigated how mixed feeding affects the gut microbiome composition and metabolic profiles compared to exclusive breastfeeding or formula feeding. Herein, how delivery mode and early nutrition affect the microbiome and metabolome of 6-week-old infants in the STRONG Kids2 cohort was investigated. Fecal samples were collected from exclusively breastfed (BF; n = 25), formula-fed (FF; n = 25) or mixed-fed (MF; n = 25) participants. Within each feeding group, infants were either delivered vaginally (VD; n = 13) or by Cesarean section (CS; n = 12). Feeding mode affects the fecal microbiome diversity, composition, and functional potential, as well as metabolomic profiles regardless of delivery mode. Alpha and beta diversity of MF differed from that of BF (p < 0.05) but were comparable to FF infants. Functional analyses have shown 117 potential metabolic pathways differed between BF and FF, 112 between BF and MF, and 8 between MF and FF infants (p < 0.05, q < 0.10). Fecal metabolomic profiles of MF and FF clustered together and separated from BF infants. In total, 543 metabolites differed between BF and FF, 517 between BF and MF, and 3 between MF and FF (p < 0.05, q < 0.10). Delivery mode affected overall microbial composition (p = 0.022) at the genus level and 24 potential functional pathways, with 16 pathways being higher in VD than CS infants (p < 0.05, q < 0.10). Metabolomic analysis identified 47 differential metabolites between CS and VD, with 39 being lower in CS than VD (p < 0.05, q < 0.10). In summary, fecal microbiota composition and function and metabolite profiles of 6-week-old MF infants are closer to FF than BF infants.

Association between Exclusive Breastfeeding and the Incidence of Childhood Nephrotic Syndrome

OBJECTIVE

To assess the relationship between breastfeeding and the risk of developing nephrotic syndrome using a population-based nationwide birth cohort in Korea.

STUDY DESIGN

This nationwide cohort study utilized data from the National Health Information Database and the National Health Screening Program for Infants and Children. The study included all children born between January 1, 2010, and December 31, 2018, who underwent their first health screening, which included a specific questionnaire on breastfeeding between 4 and 6 months of age. Associations between nephrotic syndrome and exclusive breastfeeding were estimated using adjusted hazard ratios (aHR) derived from Cox proportional hazards models, adjusted for sociodemographic variables, with follow-up until the occurrence of nephrotic syndrome, 8 years postindex date, death, or December 31, 2022, whichever was first.

RESULTS

The study population comprised 1 787 774 children (median follow-up: 7.96 years; IQR: 6.31-8.00 years), including 612 556 exclusively breastfed and 1 175 218 formula-fed children. Exclusive breastfeeding was associated with a decreased risk of developing nephrotic syndrome (aHR: 0.80; 95% CI: 0.69-0.93). Subgroup analysis stratified by sex mirrored the overall findings, although statistical significance was not observed in girls (boys: aHR, 0.75; 95% CI, 0.62-0.92; girls: aHR, 0.87; 95% CI, 0.70-1.09). Sensitivity analysis confirmed these results.

CONCLUSIONS

Exclusive breastfeeding was associated with a 20% reduced risk of developing nephrotic syndrome up to 8 years of age.

Human milk whey proteins: Constituents, influencing factors, detection methods, and comparative analysis with other sources

Whey proteins, the most abundant proteins in human milk (HM), play a vital role in the growth and development of infants. This review first elaborates on the main components of HM whey proteins, including various proteins with specific functions, and details the functions of these proteins in terms of infant nutrition, immunity, as well as growth and development. Secondly, it analyzes factors that affect HM whey proteins, such as maternal differences, dietary habits, and geographical differences. Thirdly, it discusses detection methods for HM whey proteins, covering the principles, advantages, and limitations of different technical means. Finally, it compares whey proteins from different milk sources, highlighting their differences in composition, function, and characteristics. This review aims to comprehensively present the current research status of HM whey protein, provide a scientific basis for maternal and infant health, and contribute to optimizing infant feeding strategies and the research and development of related products.

Association between breastfeeding duration and educational attainment in rural Southwest Uganda: a population-based cohort study

BACKGROUND

Breastfeeding is important for early childhood nutrition and health. The positive effects on educational outcomes may be attributed to socioeconomic factors. Socioeconomic status is not a strong predictor of breastfeeding in sub-Saharan African countries. Yet, few studies have investigated the association between breastfeeding and educational outcomes in these countries.

OBJECTIVE

This study investigated the association between breastfeeding duration and children's educational attainment in rural Southwest Uganda.

METHODS

We analysed longitudinal data on 3018 children who had information on breastfeeding and were followed for at least 5 years, with at least one primary school grade recorded by 2005. Data on breastfeeding duration were collected from mothers. The highest school grade was recorded repeatedly between ages 6 and 12 years. We calculated age-for-grade based on whether a child was on, over, or under the official age for a grade. Generalised estimating equations and binary logistic regression estimated the effect of breastfeeding duration on being 2 years, 3 or more years, or any years over-age for grade in primary school, adjusting for socioeconomic status and maternal-child characteristics.

RESULTS

Most mothers breastfed for more than a year. Just over one-third breastfed for 18-23 months, and 30% breastfed for longer. By age eight, 42% of the children were two years over-age for their grade. Three or more years over-age for grade increased from 19% at age nine to 56% at age 12. Both adjusted and unadjusted estimates were consistent in showing reduced odds for children being 2 years, 3 or more years, or any years over-age for grade among children breastfed for 7-12, 13-17, 18-23, and > 23 months compared to those breastfed for 0-6 months. There was no evidence to support an overall association between breastfeeding duration and being over-age for grade. There was no evidence of association in the sex and age sub-group analyses.

CONCLUSION

Although we found no association between breastfeeding duration and educational attainment, breastfeeding remains important for children's health and nutrition, and mothers should be encouraged and supported to breastfeed for the recommended duration.

Therapeutic potential of human breast milk-derived exosomes in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe inflammatory and necrotizing disease of the intestine that primarily affects the neonates, particularly premature infants. It has a high incidence of approximately 8.9% in extremely preterm infants, with a mortality rate ranging from 20 to 30%. In recent years, exosomes, particularly those derived from breast milk, have emerged as potential candidates for NEC therapy. Human breast milk-derived exosomes (BME) have been shown to enhance intestinal barrier function, protect intestinal epithelial cells from oxidative stress, promote the proliferation and migration of intestinal epithelial cells, and reduce the severity of experimental NEC models. As a subset of extracellular vesicles, BME possess the membrane structure, low immunogenicity, and high permeability, making them ideal vehicles for the treatment of NEC. Additionally, exosomes derived from various sources, including stem cells, intestinal epithelial cells, plants, and bacteria, have been implicated in the development and protection of intestinal diseases. This article summarizes the mechanisms through which exosomes, particularly BME, exert their effects on NEC and discusses the feasibility and obstacles associated with this novel therapeutic strategy.

Role of maternal milk in providing a healthy intestinal microbiome for the preterm neonate

The immature gastrointestinal tract of preterm neonates leads to a delayed and distinctive establishment of the gut microbiome, making them susceptible to potentially pathogenic bacteria and increasing the risk of infections. Maternal milk, recognized as the optimal source of nutrition, plays a multifaceted role in modulating the gut microbiome of premature newborns. Human milk oligosaccharides, acting as prebiotics, provide essential nourishment for key bacteria such as Bifidobacterium, contributing to the proliferation of beneficial bacterial populations. Additionally, maternal milk is rich in Immunoglobulins that stimulate immune cell responses, providing protective effects on the infant's gut mucosa. Moreover, bioactive proteins such as secretory immunoglobulin A (SIgA), lactoferrin, lysozyme, and mucins play a crucial role in defending against pathogens and regulating the immune system at the cellular level. These proteins contribute not only to infection prevention but also emphasize the impact of breast milk in fortifying the body's innate defenses. This multifaceted role of maternal milk, including essential nutrients, beneficial bacteria, and bioactive proteins, highlights the importance of promoting the mother's own milk feeding in the Neonatal Intensive Care Unit (NICU). It not only optimizes the long-term outcomes and well-being of preterm infants but also provides a holistic approach to their health and development. IMPACT: This article contributes to the current understanding of the relationship between breastfeeding and the intestinal microbiota. Fill gaps in existing literature about the subject. Provides new insights for future research.

Experiences of breastfeeding among mothers of preterm infants during their infants' hospital stay: a qualitative systematic review protocol

OBJECTIVE

The objective of this review is to synthesize the existing qualitative evidence on the breastfeeding experiences of mothers of hospitalized preterm infants.

INTRODUCTION

Breastfeeding is crucial for the well-being and development of preterm infants born before 37 weeks' gestation. Mothers of preterm infants often face challenges that make breastfeeding particularly complex. Understanding mothers' breastfeeding experience is important for health care professionals, as it enables them to provide appropriate support and assistance. The qualitative evidence synthesis regarding the breastfeeding experiences of mothers of preterm infants in hospital settings is a valuable area of research that has not been documented.

INCLUSION CRITERIA

This review will consider all qualitative studies that explore mothers' experiences of breastfeeding and mother's own milk management for their hospitalized infants. Mothers of preterm infants who provide their own milk to their infants will be considered, regardless of their age, gravidity, parity, singleton/multiple pregnancies, gender identity, marital status, social status, or preterm infant's gestational age.

METHODS

This review will follow the JBI approach for qualitative systematic review. The search strategy aims to find both published and unpublished studies, with no date limit. A search of PubMed, CINAHL (EBSCOhost), and Embase (EBSCOhost) will be undertaken to identify articles on the topic. Studies published in English will be considered for inclusion in this review. Two independent reviewers will evaluate the methodological validity of the selected papers before incorporating them into the review. Data synthesis will be conducted using the meta-aggregation approach, and synthesized findings will be assessed using the ConQual approach.

REVIEW REGISTRATION

PROSPERO CRD42024501454.

Autism Spectrum and gastrointestinal health: Screening on the influence of environmental factors on gastrointestinal problems

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that combines genetic and environmental factors. The human microbiota is colonized by permanent or transitory microorganisms, depending on the host and the external factors controlling their permanence. The composition of the gut microbiota (GM) in ASD individuals is notably different from that in controls, which may contribute to the clinical conditions observed in these individuals. This study aimed to indirectly investigate the influence of GM on the gut-brain axis in individuals with ASD and controls by analyzing environmental factors that contribute to the microbiota composition. Two questionnaires were designed to collect data, one for the ASD Group (ASDG) and the other one for the Control Group (CG). The raw data from both questionnaires were collected from 2772 respondents. After triage, answers from 1687 ASD individuals, along with 466 respondents from the CG, were analyzed, resulting in a total of 2237 respondents. Our results showed that gastrointestinal problems (GP) escalate as individuals age and become more prominent in ASD individuals. In contrast, feeding problems (FP) did not appear to escalate in either group as individuals aged, even though the FP decreased in the CG. ANOVA revealed significant differences in breastfeeding status compared to GPs among preterm control individuals born via cesarean section (p-value = 0.027). The mean values of GP for breastfed and nonbreastfed individuals, for ASDG (0.257; 0.268) and CG (0.105; 0.248), highlighted the differences in breastfeeding effects on GP for the study groups. The use of antibiotics during pregnancy seemed to be significant for GPs in the ASDG only for breastfed individuals (p-value <0.001), but not in the CG group. In conclusion, variables such as mode of delivery, FPs, type of birth, and length of breastfeeding do not seem to be determining factors for GP in the ASDG but are relevant for the CG. However, for ASDG individuals whose mothers took antibiotics during pregnancy, breastfeeding may act as a protective factor, as maternal antibiotic administration during pregnancy seems to aggravate GP-values across the ages of the participants. Considering GP as a proxy for GM and recognizing the importance of GM composition for central nervous system (CNS) function, it appears that in individuals with ASD, GM seems to be more dependent on other factors, which might be linked to the genetic background of each one. These findings suggest that future studies of the gut-brain axis in individuals with ASD might consider the individual's genetic background, environmental factors, and GM.

The Association of Short-Chain Fatty Acids with the Occurrence of Gastrointestinal Symptoms in Infants

Short-chain fatty acids (SCFAs) are produced by the fermentation of undigested polysaccharides; they are a group of metabolites resulting from the activity of intestinal bacteria. The main SCFAs are acetic, butyric, propionic, valeric, and caproic acid, and their levels and proportions depend on various factors. The aim of this study was to investigate the relationship between the concentration of SCFAs and the occurrence of specific gastrointestinal symptoms in infants. This study was conducted using faecal samples obtained at 1, 3, 6, and 12 months of age. The SCFA content was measured using gas chromatography. At 1 month, an association was found between butyric acid and flatulence. At 3 months, an association was found between butyric acid and flatulence/gas and between 3,4-methylovaleric acid and mucus in the stool. At 6 months, an association was found between butyric and valeric acids and flatulence. By 12 months, the gastrointestinal symptoms had decreased significantly. This study confirms that there is an association between SCFA levels and the presence of bloating, gas, mucus in the stool, and constipation in the gastrointestinal tract. Higher levels of butyric and valeric acids may lead to an increase in troublesome symptoms, such as flatulence and gas, in the first few months of life but are not associated with the occurrence of intestinal colic. The level of 3,4-methylovaleric acid is associated with the presence of allergies, whereas a decrease in acetic acid and an increase in isovaleric acid may exacerbate defecation problems in infants.

Associations between human milk EV-miRNAs and oligosaccharide concentrations in human milk

Introduction

Human milk contains human milk oligosaccharides (HMOs) and microRNAs (miRNAs), which are key bioactive components. HMOs are indigestible carbohydrates that impact infant growth and development. miRNAs are small, non-coding RNAs that regulate post-transcriptional gene expression. miRNAs are abundant in human milk and can be contained in extracellular vesicles (EVs). There is evidence that miRNAs are synthesized in the mammary epithelium and may influence mammary gland development and milk synthesis. However, the relationships between miRNAs and HMOs have yet to be fully characterized.

Methods

This study examined the associations between 210 human milk EV-miRNAs and 19 HMOs in a cohort of 98 Latina mothers. HMO measures included summary measures and concentrations of 19 HMOs. Relationships between EV-miRNAs and HMOs were examined using principal components analysis and associations between individual EV-miRNAs and HMOs were assessed.

Results

Overall patterns of EV-miRNA levels, summarized using principal components, were associated with HMO summary measures and concentrations. Levels of individual EV-miRNAs were associated with HMO summary measures and individual concentrations of 2'FL, 3FL, 3'SL, 6'SL, FLNH, LNFP I, and LNH.

Discussion

Results from this study suggest that human milk EV-miRNAs are associated with the concentration of HMOs, which may have important effects on infant growth and development.

Milk-Derived Extracellular Vesicles: A Novel Perspective on Comparative Therapeutics and Targeted Nanocarrier Application

Milk-derived extracellular vesicles (mEVs) are emerging as promising therapeutic candidates due to their unique properties and versatile functions. These vesicles play a crucial role in immunomodulation by influencing macrophage differentiation and cytokine production, potentially aiding in the treatment of conditions such as bone loss, fibrosis, and cancer. mEVs also have the capacity to modulate gut microbiota composition, which may alleviate the symptoms of inflammatory bowel diseases and promote intestinal barrier integrity. Their potential as drug delivery vehicles is significant, enhancing the stability, solubility, and bioavailability of anticancer agents while supporting wound healing and reducing inflammation. Additionally, bovine mEVs exhibit anti-aging properties and protect skin cells from UV damage. As vaccine platforms, mEVs offer advantages including biocompatibility, antigen protection, and the ability to elicit robust immune responses through targeted delivery to specific immune cells. Despite these promising applications, challenges persist, including their complex roles in cancer, effective antigen loading, regulatory hurdles, and the need for standardized production methods. Achieving high targeting specificity and understanding the long-term effects of mEV-based therapies are essential for clinical translation. Ongoing research aims to optimize mEV production methods, enhance targeting capabilities, and conduct rigorous preclinical and clinical studies. By addressing these challenges, mEVs hold the potential to revolutionize vaccine development and targeted drug delivery, ultimately improving therapeutic outcomes across various medical fields.

Modelling the temporal trajectories of human milk components

BACKGROUND

This paper demonstrates how available data can be explored and utilized to conclude generic patterns in the temporal changes in Human Milk (HM) composition.

METHODS

The temporal trajectories of selected human milk components (HMC-s) were described, in the first four months postpartum, by a primary model consisting of two phases: a short linear phase in the colostrum, triggered by the parturition; and a longer second phase, where the concentration of the component converges to a steady state. The model was fitted to data available in a recently published database of temporal HMC trajectories both at the levels of individual molecules (such as specific fatty acid, oligosaccharide, and mineral molecules) and molecule-groups (such as total protein, total fat).

RESULTS

The properties of the trajectories suggest that experimental designs should follow non-equidistant sampling times, with increasingly longer time intervals after the first week postpartum. A selected parameter, the final stationary level, of the primary model was then studied as a function of geographical location (secondary modelling).

CONCLUSIONS

We found that the total variation of the concentration of specific HMC-s is dominantly due to the inherent biological differences between individual mothers and to less extent to the geographical location.

Dysregulated blood biomarkers in women with acute and chronic respiratory conditions due to air pollutant exposure: An exploratory systematic review

Background

Air pollution exposure poses significant health risks for the general population, but particularly for women with acute and chronic respiratory conditions. Given the increasing global burden of air pollution-related illnesses, understanding these biomarkers is crucial for developing targeted interventions and improving respiratory health outcomes in vulnerable populations. In this systematic review, we aimed to determine potential dysregulated respiratory inflammatory blood biomarker candidates in adult female patients who experience varying levels and sources of inhaled pollutant exposure.

Methods

We searched the Cochrane Library, PubMed, and Web of Science with nuanced search terms to retrieve articles published in English between 1 January 2000 and 12 June 2023, to ensure relevancy. We filtered our findings to generate a focussed narrative analysis and used the Risk of Bias In Non-randomized Studies-of Exposures (ROBINS-E) and Risk-of-bias VISualization (robVIS) tools to ensure the validity of the data and the quality of the conclusions being made.

Results

We identified 916 articles from the databases used in our search, 16 of which met the criteria of our focussed narrative analysis. Among blood biomarkers, platelet-activating factor and eosinophilia could be used to assess the severity of asthma conditions, as a lack or reduction thereof indicates specific conditions. Pro-inflammatory cytokines require further validation, as some studies with a high risk of bias have reported conflicting results compared to more recent research on whether these markers are up-regulated or down-regulated. We found one study to be at a very high risk of bias, two had a high risk of bias, one had some concerns of confounding factors which may not have affected their results, and 12 studies had a low risk of bias.

Conclusions

There were narrowed-down blood biomarker candidates that could be used in future research and avenues of research like generating specific microRNA sequences to test for prognostic/diagnostic tests.

Registration

PROSPERO: 42023435721.

Evolutionary bridges: how factors present in amniotic fluid and human milk help mature the gut

Necrotizing enterocolitis (NEC) continues to be a leading cause of morbidity and mortality in preterm infants. As modern medicine significantly improves the survival of extremely premature infants, the persistence of NEC underscores our limited understanding of its pathogenesis. Due to early delivery, a preterm infant's exposure to amniotic fluid (AF) is abruptly truncated. Replete with bioactive molecules, AF plays an important role in fetal intestinal maturation and preparation for contact with the environment, thus its absence during development of the intestine may contribute to increased susceptibility to NEC. Human milk (HM), particularly during the initial phases of lactation, is a cornerstone of neonatal intestinal defense. The concentrations and activities of several bioactive factors in HM parallel those of AF, suggesting continuity of protection. In this review, we discuss the predominant overlapping bioactive components of HM and AF, with an emphasis on those associated with intestinal growth or reduction of NEC.

Goat Milk Exosomes Ameliorate Ulcerative Colitis in Mice through Modulation of the Intestinal Barrier, Gut Microbiota, and Metabolites

Goat milk is rich in a variety of nutrients that are important for intestinal health and disease prevention. However, the role of exosomes in goat milk remains to be elucidated. This study investigated for the first time the therapeutic efficacy and molecular underlying mechanisms of mature milk exosomes (M-exo) and goat colostrum exosomes (C-exo) on dextran sodium sulfate-induced ulcerative colitis (UC) in mice. The findings demonstrate that M-exo and C-exo significantly improved physiological indices, suppressed the secretion of proinflammatory cytokines, and diminished oxidative stress and apoptosis in UC mice. Moreover, C-exo and M-exo restored the intestinal barrier function, remodeled the gut microbiota, and improved metabolite composition in the feces of colitis mice. In conclusion, goat milk exosomes ameliorate UC in mice, which provides a basis for the development of functional food applications for the prevention and treatment of inflammatory bowel disease.

Influence of Lactation Stage on Content of Neurotrophic Factors, Leptin, and Insulin in Human Milk

Human milk comprehensively meets the nutritional needs of a child, providing not only structural and energy components but also various bioactive factors. Among these, neurotrophic factors and hormones involved in metabolic processes deserve special attention. Studies using enzyme-linked immunosorbent assays compared the content of neurotrophic factors-CNTF, NT-3, and NGF-and hormones, leptin and insulin, in two groups of breast milk samples: early lactation (1-3 months) and extended lactation (>6 months, up to 12 months). The results indicated changes in leptin and insulin levels as the lactation period extended. NGF, leptin, and insulin were present in milk samples from both study groups, with leptin and insulin levels being higher in the early lactation group. CNTF and NT-3 were not detected in any of the samples from either study group. The analyses confirmed that human milk from women who breastfeed for extended periods remains a source of biologically active components and macronutrients that support a child's development and health.

Human Breast Milk Exosomes: Affecting Factors, Their Possible Health Outcomes, and Future Directions in Dietetics

Background: Human breast milk is a complex biological fluid containing multifaceted biological compounds that boost immune and metabolic system development that support the short- and long-term health of newborns. Recent literature suggests that human breast milk is a substantial source of nutrients, bioactive molecules, and exosomes. Objectives: This review examines the factors influencing exosomes noted in human milk and the impacts of exosomes on infant health. Furthermore, it discusses potential future prospects for exosome research in dietetics. Methods: Through a narrative review of the existing literature, we focused on exosomes in breast milk, exosome components and their potential impact on exosome health. Results: Exosomes are single-membrane extracellular vesicles of endosomal origin, with an approximate radius of 20-200 nm. They are natural messengers that cells secrete to transport a wide range of diverse cargoes, including deoxyribonucleic acid, ribonucleic acid, proteins, and lipids between various cells. Some studies have reported that the components noted in exosomes in human breast milk could be transferred to the infant and cause epigenetic changes. Thus, it can affect gene expression and cellular event regulation in several tissues. Conclusions: In this manner, exosomes are associated with several pathways, including the immune system, oxidative stress, and cell cycle, and they can affect the short- and long-term health of infants. However, there is still much to learn about the functions, effectiveness, and certain impacts on the health of human breast milk exosomes.

Microbiota regulates neonatal disease tolerance to virus-evoked necrotizing enterocolitis by shaping the STAT1-NLRC5 axis in the intestinal epithelium

Microbiota and feeding modes influence the susceptibility of premature newborns to necrotizing enterocolitis (NEC) through mechanisms that remain unknown. Here, we show that microbiota colonization facilitated by breastmilk feeding promotes NOD-like receptor family CARD domain containing 5 (Nlrc5) gene expression in mouse intestinal epithelial cells (IECs). Notably, inducible knockout of the Nlrc5 gene in IECs predisposes neonatal mice to NEC-like injury in the small intestine upon viral inflammation in an NK1.1+ cell-dependent manner. By contrast, formula feeding enhances neonatal gut colonization with environment-derived tilivalline-producing Klebsiella spp. Remarkably, tilivalline disrupts microbiota-activated STAT1 signaling that controls Nlrc5 gene expression in IECs through a PPAR-γ-mediated mechanism. Consequently, this dysregulation hinders the resistance of neonatal intestinal epithelium to self-NK1.1+ cell cytotoxicity upon virus infection/colonization, promoting NEC development. Together, we discover the underappreciated role of intestinal microbiota colonization in shaping a disease tolerance program to viral inflammation and elucidate the mechanisms impacting NEC development in neonates.

Vaccine response was higher in formula-fed infants compared to breastfed but not affected by lactoferrin or iron in a randomised controlled trial

AIM

To examine how reduced iron content and added bovine lactoferrin in infant formula affect the antibody response following routine immunisation.

METHODS

In this randomised controlled trial, 180 Swedish formula-fed infants received, from 6 weeks to 6 months of age, a 2 mg/L iron formula with (n = 72) or without (n = 72) bovine lactoferrin, or a control formula with 8 mg/L iron and no lactoferrin (n = 36). Another 72 infants were recruited as a breastfed reference. Serum immunoglobulin G (IgG) levels against Haemophilus influenzae type b (Hib), diphtheria and tetanus were assessed at four, six and 12 months of age.

RESULTS

With an equal gender distribution, 180 + 72 term infants were included with a mean age of 7.0 ± 0.7 weeks. At 12 months, infants fed low iron formula showed a significantly higher geometric mean Hib IgG (1.40 μg/mL [1.07-1.83]) compared to the control formula infants (0.67 μg/mL [0.42-1.07]). For all three vaccines, breastfed infants had significantly lower IgG levels at six and 12 months of age.

CONCLUSION

Except for higher Hib IgG levels at 12 months in infants fed low iron formula, the interventions did not affect vaccine IgG response. Unexpectedly, breastfed infants had significantly lower vaccine IgG levels compared to formula-fed infants.

The conundrum of intestinal injury in preterm infants receiving mother's own milk

"Necrotizing enterocolitis" ("NEC") is a heterogeneous group of intestinal injuries experienced primarily in preterm infants. Risk factors include among others preterm gut microbiome alterations. Maternal milk (MM), or otherwise parent milk, is protective for the developing intestine due to its constituents, which include bioactive antimicrobials, immunomodulatory molecules, human milk oligosaccharides (HMOs), secretory immunoglobulin A (sIgA), and microorganisms. However, some preterm infants receiving exclusively mother's own milk (MOM) develop intestinal injuries. Studies showed predisposition to increased risk for "NEC", when a decreased MM HMO, disialyllacto-N-tetraose, is combined with an altered infant's gut microbiome. The intestine may also become more prone to injury with a greater amount of bacteria not bound to IgA. Variations in MM composition may alter the offspring gut microbiome, depriving protection. The different "NEC" entities should be considered to play a role as to why, in many studies, MOM does not provide absolute protection against preterm intestinal injury.

Evolutive Study of Dietary Aspects and Intestinal Microbiota of Pediatric Cohort with Cow's Milk Protein Allergy

BACKGROUND

One of the most common food allergies in the pediatric population is allergy to cow's milk protein (CMPA). Treatment consists of avoiding cow's milk proteins in lactating mothers and/or using therapeutic formulas based on hydrolysates or vegetable formulas. In infants with CMPA at diagnosis, a different gut microbial profile has been found compared to healthy children, with a reduction in beneficial bacteria. The aim of this study was to evaluate changes in the gut microbiota profile and its metabolites, dietary patterns and anthropometric variables in a pediatric cohort with CMPA after six months on a restrictive diet compared to healthy controls.

METHODS

In total, 21 patients diagnosed with CMPA and a control group of 24 healthy infants participated in this study. The fecal microbiota of all participants were investigated by metataxonomic analysis of 16S rDNA amplicons, and fecal short-chain fatty acids were measured by gas chromatography. Epidemiological assessment and dietary questionnaires were carried out for both groups.

RESULTS

Regarding growth, no significant differences were found, but differences in dietary intake of some macro- and micronutrients were observed. Patients who were breastfed at six months had higher bifidobacteria and lipid intakes than patients fed with hydrolyzed formulas.

CONCLUSIONS

Although the growth of CMPA infants fed with therapeutic formula is similar to breastfed CMPA infants, there are differences in microbiota composition and macronutrient intake that underline the importance of continued breastfeeding in CMPA cases.

Recent Progress in Physiological Significance and Biosynthesis of Lacto-N-triose II: Insights into a Crucial Biomolecule

Lacto-N-triose II (LNTri II), an important precursor for human milk oligosaccharide (HMOs) synthesis, has garnered significant attention due to its structural features and physiological properties. Composed of galactose (Gal), N-acetylglucosamine (GlcNAc), and glucose (Glc), with the chemical structure GlcNAcβ1,3Galβ1,4Glc, the distinctive structure of LNTri II confers various physiological functions such as promoting the growth of beneficial bacteria, regulating the infant immune system, and preventing certain gastrointestinal diseases. Extensive research efforts have been dedicated to elucidating efficient enzymatic synthesis pathways for LNTri II production, with particular emphasis on the transglycosylation activity of β-N-acetylhexosaminidases and the action of β-1,3-N-acetylglucosaminyltransferases. Additionally, metabolic engineering and cell factory approaches have been explored, harnessing the potential of engineered microbial hosts for the large-scale biosynthesis of LNTri II. This review summarizes the structure, derivatives, physiological effects, and biosynthesis of LNTri II.

Inter-individual and inter-regional variability of breast milk antibody reactivity to bacterial lipopolysaccharides

Breast milk is a vital source of nutrients, prebiotics, probiotics, and protective factors, including antibodies, immune cells and antimicrobial proteins. Using bacterial lipopolysaccharide arrays, we investigated the reactivity and specificity of breast milk antibodies towards microbial antigens, comparing samples from rural Kenya and urban Switzerland. Results showed considerable variability in antibody reactivity both within and between these locations. Kenyan breast milk demonstrated broad reactivity to bacterial lipopolysaccharides, likely due to increased microbial exposure. Antibodies primarily recognized the O-antigens of lipopolysaccharides and showed strong binding to specific carbohydrate motifs. Notably, antibodies against specific Escherichia coli O-antigens showed cross-reactivity with parasitic pathogens like Leishmania major and Plasmodium falciparum, thus showing that antibodies reacting against lipopolysaccharide O-antigens can recognize a wide range of antigens beyond bacteria. The observed diversity in antigen recognition highlights the significance of breast milk in safeguarding infants from infections, particularly those prevalent in specific geographic regions. The findings also offer insights for potential immunobiotic strategies to augment natural antibody-mediated defense against diverse pathogens.

Microbiological status of donor human milk - A single center study from Poland

Human milk is considered the most suitable source of nutrition for infants. Donor human milk from human milk banks (HMB) is recommended as the best alternative for infants whose mothers' own milk is unavailable. Microbiological screening of milk donated to HMB is important to ensure the quality and safety of the pasteurised human milk. This article describes the microbiological status of human milk donated to the Regional Human Milk Bank in Toruń, Poland. Statistical data regarding the microbiological analysis of milk from 292 donors were collected in the years 2013-2021. Total of 538 milk samples were tested. Only in 6% of human milk samples the bacteria level was above the required standard and/or the milk had potentially pathogenic bacteria. The main core of donors' breastmilk bacteria represents the skin microbiota, and the composition of the microbiota is strictly related to the surrounding environment. The most abundant genera detected in milk samples were the Staphylococcus group. Prolonged hospitalisation of infants' mothers and/or offsprings is associated with potentially pathogenic bacteria colonization in milk. The use of the modern identification method MALDI-TOF resulted in more accurate results compared to the biochemical methods. Our analysis indicates that most of the tested milk samples (94%), both expressing at home and in hospital environments, meet the criteria for admission to the human milk bank. Effective techniques for identifying microorganisms ensure that donor milk from human milk banks meets the guidelines set for these units.

Correlation between serum vitamin D level and acute invasive enteritis in children

BACKGROUND

Diarrhea is a leading cause of death in young children worldwide. Vitamin D deficiency impairs the body's ability to clear pathogens, reduces tight junction protein expression in intestinal epithelial cells, and enhances Th1-mediated intestinal inflammation. This study aimed to investigate the effects of serum vitamin D levels on acute invasive enteritis in children.

METHODS

This prospective cohort study included 82 children aged 1-3 years with clinically diagnosed acute invasive enteritis at Sichuan Maternal and Child Health Hospital from February 2021 to February 2022, alongside a control group of 80 healthy children. Fecal specimens were collected for routine tests and occult blood analysis, while blood samples were taken for routine tests, C-reactive protein, and 25-OHD levels. Comparative analyses were performed between groups, and multifactorial logistic regression was used to identify factors influencing invasive enteritis.

RESULTS

The study group showed significantly lower serum 25-OHD levels (27.95 ± 9.91 ng/mL) compared to controls (32.76 ± 10.23 ng/mL, p < .01). Among the study group, 19.5% (16/82) had levels <20 ng/mL, versus 12.5% (10/80) in controls. Regular vitamin D supplementation was lower in the study group (58.5% vs. 77.5%, p < .05). Outdoor activity duration was also reduced (2.57 ± 0.98 h vs. 3.04 ± 0.88 h, p < .01). Multivariate analysis identified that exclusive breastfeeding, greater outdoor activity time and regular vitamin D supplementation were all associated with reduced risk of invasive enteritis (p < .05).

CONCLUSION

The findings indicate an association between low serum 25-OHD levels and acute invasive enteritis in children aged 1-3 years, suggesting that consistent vitamin D supplementation and sufficient outdoor activity may protect against this condition.

Lactoferrin Supplementation during Pregnancy and Lactation Protects Adult Male Rat Offspring from Hypertension Induced by Maternal Adenine Diet

Lactoferrin, a glycoprotein derived from breastmilk, is recognized for its health benefits in infants and children; however, its protective effects when administered during gestation and lactation against offspring hypertension remain unclear. This study aimed to investigate whether maternal lactoferrin supplementation could prevent hypertension in offspring born to mothers with chronic kidney disease (CKD), with a focus on nitric oxide (NO), renin-angiotensin system (RAS) regulation, and alterations in gut microbiota and short-chain fatty acids (SCFAs). Prior to pregnancy, female rats were subjected to a 0.5% adenine diet for 3 weeks to induce CKD. During pregnancy and lactation, pregnant rats received one of four diets: normal chow, 0.5% adenine diet, 10% lactoferrin diet, or adenine diet supplemented with lactoferrin. Male offspring were euthanized at 12 weeks of age (n = 8 per group). Supplementation with lactoferrin during gestation and lactation prevented hypertension in adult offspring induced by a maternal adenine diet. The maternal adenine diet caused a decrease in the index of NO availability, which was restored by 67% with maternal LF supplementation. Additionally, LF was related to the regulation of the RAS, as evidenced by a reduced renal expression of renin and the angiotensin II type 1 receptor. Combined maternal adenine and LF diets altered beta diversity, shifted the offspring's gut microbiota, decreased propionate levels, and reduced the renal expression of SCFA receptors. The beneficial effects of lactoferrin are likely mediated through enhanced NO availability, rebalancing the RAS, and alterations in gut microbiota composition and SCFAs. Our findings suggest that maternal lactoferrin supplementation improves hypertension in offspring in a model of adenine-induced CKD, bringing us closer to potentially translating lactoferrin supplementation clinically for children born to mothers with CKD.

Lactoferrin alleviates chronic low‑grade inflammation response in obese mice by regulating intestinal flora

Chronic low‑grade inflammation defines obesity as a metabolic disorder. Alterations in the structure of gut flora are strongly associated with obesity. Lactoferrin (LF) has a biological function in regulating intestinal flora. The present study aimed to investigate the therapeutic and anti‑-inflammatory effects of LF in obese mice based on intestinal flora. A total of 30 C57BL/6 mice were divided into three groups consisting of 10 mice each. Subsequently, one group was fed a normal diet (Group K), another group was fed a high‑fat diet (Group M) and the remaining group switched from regular drinking to drinking 2% LF water (Group Z2) after 2 weeks of high‑fat diet; all mice were fed for 12 weeks. After the experiment, the mouse blood lipid and lipopolysaccharide levels, levels of inflammatory factors and intestinal tight junction proteins were assessed. Mouse stool samples were analyzed using 16S ribosomal RNA sequencing. The results showed that LF reduced serum total cholesterol, triglycerides and low‑density lipoprotein levels, elevated high‑density lipoprotein levels, suppressed metabolic endotoxemia and attenuated chronic low‑grade inflammatory responses in obese mice. In addition, LF upregulated zonula occludens‑1 and occludin protein expression levels in the intestine, thereby improving intestinal barrier integrity. LF altered the intestinal microbial structure of obese mice, reduced the ratio of Firmicutes and an elevated ratio of Bacteroidota, modifying the bacterial population to the increased relative abundance of Alistipes, Acidobacteriota, Psychrobacter and Bryobacter.