Components of human breast milk: from macronutrient to microbiome and microRNA

Effect of partially hydrolyzed synbiotic formula milk on weight gain of late preterm and term infants-a multicenter study

Introduction

Data on the effectiveness of hydrolyzed infant formula containing both pre- and probiotics (synbiotic formula) on the growth of infants is still scarce. This retrospective study was designed to evaluate the effect of a partially hydrolyzed synbiotic formula on growth parameters and the possible occurrence of major gastrointestinal adverse events or morbidities in infants born via cesarean section (C-section) delivery.

Methods

C-section-delivered term and late preterm infants who received either partially hydrolyzed synbiotic formula, standard formula, or maternal milk and followed at seven different hospitals from five different regions of Turkey, during a 1-year period with a minimum follow-up duration of 3 months were evaluated retrospectively. All the included infants were evaluated for their growth patterns and any kind of morbidity such as diarrhea, constipation, vomiting, infection, or history of hospitalization.

Results

A total of 198 infants (73 in the human milk group, 61 in the standard formula group, and 64 in the partially hydrolyzed synbiotic formula group) reached the final analysis. The groups were similar regarding their demographic and perinatal characteristics. No difference was observed between the three groups regarding gastrointestinal major side effects. Growth velocities of the infants in the human milk and partially hydrolyzed synbiotic formula groups during the first month of life were similar whereas the weight gain of infants in the standard formula group was significantly less than these two groups (p < 0.001). Growth velocities were similar among the three groups between 1st and 3rd months of age.

Discussion

A partially hydrolyzed synbiotic formula provided better weight gain in late-preterm and term infants who were delivered via C-section delivery compared to the standard formula during the first month of life. This weight gain was similar to the infants receiving exclusively human milk. This difference was not observed in length and head circumference gain. No difference was observed in any of the parameters during the 1st-3rd months of age. Specially formulated partially hydrolyzed synbiotic formulas may reverse at least some of the negative impacts of C-section delivery on the infant and help to provide better growth, especially during the early periods of life.

Mechanism of 2'-Fucosyllactose degradation by Human-Associated Akkermansia

Among the first microorganisms to colonize the human gut of breastfed infants are bacteria capable of fermenting human milk oligosaccharides (HMOs). One of the most abundant HMOs, 2'-fucosyllactose (2'-FL), may specifically drive bacterial colonization of the intestine. Recently, differential growth has been observed across multiple species of Akkermansia on various HMOs including 2'FL. In culture, we found growth of two species, A. muciniphila Muc T and A. biwaensis CSUN-19, in HMOS corresponded to a decrease in the levels of 2'-FL and an increase in lactose, indicating that the first step in 2'-FL catabolism is the cleavage of fucose. Using phylogenetic analysis and transcriptional profiling, we found that the number and expression of fucosidase genes from two glycoside hydrolase (GH) families, GH29 and GH95, varies between these two species. During mid-log phase growth, the expression of several GH29 genes was increased by 2'-FL in both species, whereas the GH95 genes were induced only in A. muciniphila . We further show that one putative fucosidase and a β-galactosidase from A. biwaensis are involved in the breakdown of 2'-FL. Our findings indicate that that plasticity of GHs of human associated Akkermansia sp. enable access to additional growth substrates present in HMOs, including 2'-FL. Our work highlights the potential for Akkermansia to influence the development of the gut microbiota early in life and expands the known metabolic capabilities of this important human symbiont.

IMPORTANCE

Akkermansia are mucin degrading specialists widely distributed in the human population. Akkermansia biwaensis has recently been observed to have enhanced growth relative to other human associated Akkermansia on multiple human milk oligosaccharides (HMOs). However, the mechanisms for enhanced growth are not understood. Here, we characterized the phylogenetic diversity and function of select genes involved in growth of A. biwaensis on 2'-fucosyllactose (2'-FL), a dominant HMO. Specifically, we demonstrate that two genes in a genomic locus, a putative β-galactosidase and α-fucosidase, are likely responsible for the enhanced growth on 2'-FL. The functional characterization of A. biwaensis growth on 2'-FL delineates the significance of a single genomic locus that may facilitate enhanced colonization and functional activity of select Akkermansia early in life.

The Influence of the Lactation Period and the Type of Milk on the Content of Amino Acids and Minerals in Human Milk and Infant Formulas

(1) Background: This study investigated the effect of the lactation period and the type of infant formula on the content of amino acids and selected minerals in an infant's food; (2) Methods: The study material consisted of breast milk (colostrum, n = 38; transitional milk, mature milk, n = 38) and three types of infant formulas (for first and follow-on feeding). Amino acid content was determined using an automatic amino acid analyzer, while minerals were determined by the atomic absorption spectrometry (AAS) technique; (3) Results: Breast milk and infant formulas contained a full range of essential amino acids. In most cases, the content of individual amino acids and minerals decreased with increasing lactation. In infant formulas, there were higher contents of phenylalanine, glutamic acid, proline, serine, and tyrosine in follow-on milk (p < 0.05). The EAA/TAA ratio in breast milk and infant formulas was similar, but the milk differed in their qualitative composition. Infant formulas contained levels of individual minerals that were several times higher-especially Mg, Ca, Mn, and Fe.; (4) Conclusions: Colostrum is more concentrated, and the level of amino acids and minerals is higher in it; as the milk matures, it decreases. In most cases, the content of individual amino acids and minerals is higher in infant formulas than in human milk, which is established through strict Codex Alimentarius procedures to ensure the proper development of infants.

Effects of Maternal Stress on Breast Milk Production and the Microbiota of Very Premature Infants

Perinatal stress experienced by mothers of very premature newborns may influence the mother's milk and the infant's intestinal microbiota. This prospective study of mothers of very preterm infants fed with mother's own milk (MOM) was carried out in a tertiary hospital over a 2-year period. The assessment of maternal stress in 45 mothers of 52 very preterm newborns using the parental stress scale (PSS:NICU) revealed an inverse relationship between stress and MOM production in the first days of life (p = 0.012). The greatest contributor to stress was the one related to the establishment of a mother-child bond. Maternal stress was lower in mothers in whom the kangaroo method was established early (p = 0.011) and in those with a higher educational level (p = 0.032). Levels of fecal calprotectin (FC) decreased with the passage of days and were directly correlated with birthweight (p = 0.044). FC levels 7 days post-delivery were lower in newborns that received postnatal antibiotics (p = 0.027). High levels of maternal stress resulted in progressive decreases and increases in the proportions of Firmicutes and Proteobacteria species, respectively, over 15 days post-delivery, both in MOM and in fecal samples from premature newborns. These findings underscore the importance of recognizing and appropriately managing maternal stress in neonatal units, given its marked influence on both the microbiota of maternal milk and the intestinal microbiota of premature newborns.

Effects of exclusive breastfeeding on educational attainment and longitudinal trajectories of grade progression among children in a 13-year follow-up study in Malawi

The benefits of exclusive breastfeeding (EBF) for infant health and survival are well documented. However, its impact on educational outcomes has been contested and poorly researched in Africa. It has been hypothesised that positive associations reported in high-income countries can be attributed to residual confounding by socioeconomic status (SES). Our study investigated whether EBF duration in infancy is associated with educational attainment and age-for-grade attainment trajectories at school-age in rural Malawi. Longitudinal data on 1021 children at the Karonga demographic surveillance site in Malawi were analysed. Breastfeeding data were collected 3 months after birth and again at age one. The school grade of each child was recorded each year from age 6 until age 13. We calculated age-for-grade based on whether a child was at, over, or under the official expected age for a grade. Generalised estimating equations estimated the average effect of breastfeeding on age-for-grade. Latent class growth analysis identified age-for-grade trajectories, and multinomial logistic regression examined their associations with EBF. Maternal-child characteristics, SES, and HIV status were controlled. Overall, 35.9% of the children were exclusively breastfed for 6 months. Over-age for grade steadily increased from 9.6% at age 8 to 41.9% at age 13. There was some evidence that EBF for 6 months was associated with lower odds of being over-age for grade than EBF for less than 3 months (aOR = 0.82, 95%CI = 0.64-1.06). In subgroup analyses, children exclusively breastfed for 6 months in infancy were less likely to be over-age for grades between ages 6-9 (aOR = 0.64, 95%CI = 0.43-0.94). Latent class growth analysis also provided some evidence that EBF reduced the odds of falling behind in the early school grades (aOR = 0.66, 95%CI = 0.41-1.08) but not later. Our study adds to the growing evidence that EBF for 6 months has benefits beyond infant health and survival, supporting the WHO's recommendation on EBF.

Breast Milk Conferred Immunity to Infants Against COVID-19

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has notably impacted healthcare systems and everyday life worldwide. Regulatory authorities have approved the emergency use of SARS-CoV-2 vaccines due to the rapid spread of the virus. However, during vaccination testing, pregnant and breastfeeding women were initially excluded, leading to a lack of evidence-based recommendations. When taking the COVID-19 pandemic into account, breastfeeding has emerged as a potential defense mechanism against this infection due to its numerous benefits for newborns. Human breast milk contains immunoglobulins (IgA, IgG, and IgM), lactoferrin, and various cells that play an inevitable role in the newborn's protection against respiratory infections and immune system development. Various studies have highlighted that the onset and severity of respiratory infections in infants can be reduced through breastfeeding, and the effects are noticeable during the first six months of life and that breast milk also has the potential to enhance mucosal immunity and promote a diverse microbiome, reducing the risk of asthma, allergies, and enteric diseases through the provision of specific antibodies and immunological factors. Researchers have indicated that breastfeeding mothers who contracted and recovered from COVID-19 or received vaccination passed protective antibodies to their infants through breast milk. Although rare cases of detection of SARS-CoV-2 RNA in breast milk have been reported, the virus has not been cultured from these samples, suggesting a low risk of transmission to the breastfed baby. However, further research is essential to understand the extent of protection provided by breast milk against COVID-19 and the potential effect of distinct phases of lactation. Nonetheless, the current evidence supports the benefits and safety of breastfeeding during the pandemic. With appropriate safety measures, promoting breastfeeding can contribute to the overall health and well-being of infants during the phase of COVID-19.

Comparative analysis of the volatile components in Chinese breast milk from three regions

In this study, gas chromatography-mass spectrometry (GC-MS) coupled with Partial least squares Discriminant Analysis (PLS-DA) was used to analyze the volatiles in Chinese breast milk from different cities (Wuhan, Qingdao and Hohhot) and different lactation stages (colostrum and mature milk). The results showed that breast milk contained 122 volatile substances in 9 major groups, with the largest number of olefins (36) and the highest content of acids. The different volatile compounds of breast milk in three cities were heptanal, 2-pentylfuran, (E)-2,4-decadienal, (E)-2-heptenal, (E)-2-nonenal and 1-octen-3-one, colostrum and mature milk were (E)-2-heptenal, (E)-2-decenal, lauric acid, n-decanoic acid, (E)-2-nonenal and octanoic acid. This study might provide scientific data for the development and optimization of formulas that were more suitable for the health of Chinese infants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01235-4.

The Protective Role of Exosome-Derived MicroRNAs and Proteins from Human Breast Milk against Infectious Agents

Human breast milk (HBM)-derived exosomes contain various biological and immunological components. However, comprehensive immune-related and antimicrobial factor analysis requires transcriptomic, proteomic, and multiple databases for functional analyses, and has yet to be conducted. Therefore, we isolated and confirmed HBM-derived exosomes by detecting specific markers and examining their morphology using western blot and transmission electron microscopy. Moreover, we implemented small RNA sequencing and liquid chromatography-mass spectrometry to investigate substances within the HBM-derived exosomes and their roles in combating pathogenic effects, identifying 208 miRNAs and 377 proteins associated with immunological pathways and diseases. Integrated omics analyses identified a connection between the exosomal substances and microbial infections. In addition, gene ontology and the Kyoto Encyclopedia of Genes and Genomes pathway analyses demonstrated that HBM-derived exosomal miRNA and proteins influence immune-related functions and pathogenic infections. Finally, protein-protein interaction analysis identified three primary proteins (ICAM1, TLR2, and FN1) associated with microbial infections mediating pro-inflammation, controlling infection, and facilitating microbial elimination. Our findings determine that HBM-derived exosomes modulate the immune system and could offer therapeutic strategies for regulating pathogenic microbial infection.

Associations between Maternal Nutrition and the Concentrations of Human Milk Oligosaccharides in a Cohort of Healthy Australian Lactating Women

Human milk oligosaccharides (HMOs) are complex glycans associated with positive infant health outcomes. The concentrations of HMOs in the milk of lactating women are associated with substantial intra- and inter-individual differences and may be influenced by maternal physiological and/or nutrition-related factors. The primary aim of this study was to explore potential influences of short-term maternal diet and current body composition on HMO profiles in mature human milk. Milk samples were collected at 3-4 months postpartum from 101 healthy Australian women using standardised procedures, and analysed for macronutrients (lactose, fat, and protein). In addition, HMO concentrations were analysed using liquid-chromatography mass-spectrometry (LC-MS). Maternal dietary data were collected using three validated 24-h dietary recalls, and the body composition of a subgroup of mothers was assessed by DEXA scans (n = 30). Most (79%) of the women were secretor-positive. Individual nutrients were not significantly correlated with HMO concentrations after correction for multiple comparisons (p > 0.05), except for dietary folate intake. DEXA scans revealed no associations between HMO profiles and maternal body composition during established lactation. The study findings suggest a lack of clear and consistent associations between maternal nutrition and HMO concentrations in mature human milk from healthy lactating women with adequate dietary intake. The prevailing influence of genetic variation in lactating mothers may overshadow any impact of maternal nutritional and/or physiological status on HMO composition in mature human milk.

Human Milk: Fast Determination of Docosahexaenoic Acid (DHA)

Human milk provides all the nutrients required by babies during the first six months of their life. Human milk lipids represent the main source of energy, contributing almost 50% of the total energy content. Additionally, fatty acids ensure the correct development of children in the prenatal, postnatal, and infant phases. Docosahexaenoic acid (DHA) is essential for visual and cognitive development, and its presence during childhood can affect long-term health. This study aimed to optimize and validate a methodology for the direct determination of DHA in human milk. We used 20 samples of human milk from lactating women living in the city of Itu, São Paulo, who attended Basic Health Units from September 2019 to September 2020, and a sample of certified reference material from the National Institute of Standards and Technology. The proposed methodology consists of a validated mixed transesterification process without prior lipid extraction, optimized by factorial design. This methodology can be successfully used in human milk samples as it is both precise and accurate. The values of DHA in the sampled milks were similar to those in European countries and lower than those in Asian countries due to diet.

RNA in extracellular vesicles during adolescence reveal immune, energetic and microbial imprints of early life adversity

Exposure to early life adversity (ELA), including childhood maltreatment, is one of the most significant risk factors for the emergence of neuropsychiatric disorders in adolescence and adulthood. Despite this relationship being well established, the underlying mechanisms remain unclear. One way to achieve this understanding is to identify molecular pathways and processes that are perturbed as a consequence of childhood maltreatment. Ideally, these perturbations would be evident as changes in DNA, RNA or protein profiles in easily accessible biological samples collected in the shadow of childhood maltreatment. In this study, we isolated circulating extracellular vesicles (EVs) from plasma collected from adolescent rhesus macaques that had either experienced nurturing maternal care (CONT) or maternal maltreatment (MALT) in infancy. RNA sequencing of RNA in plasma EVs and gene enrichment analysis revealed that genes related to translation, ATP synthesis, mitochondrial function and immune response were downregulated in MALT samples, while genes involved in ion transport, metabolism and cell differentiation were upregulated. Interestingly, we found that a significant proportion of EV RNA aligned to the microbiome and that MALT altered the diversity of microbiome-associated RNA signatures found in EVs. Part of this altered diversity suggested differences in prevalence of bacterial species in CONT and MALT animals noted in the RNA signatures of the circulating EVs. Our findings provide evidence that immune function, cellular energetics and the microbiome may be important conduits via which infant maltreatment exerts effects on physiology and behavior in adolescence and adulthood. As a corollary, perturbations of RNA profiles related to immune function, cellular energetics and the microbiome may serve as biomarkers of responsiveness to ELA. Our results demonstrate that RNA profiles in EVs can serve as a powerful proxy to identify biological processes that might be perturbed by ELA and that may contribute to the etiology of neuropsychiatric disorders in the aftermath of ELA.

Phenylalanine free infant formula in the dietary management of phenylketonuria

BACKGROUND

Phenylalanine-free infant formula is an essential source of safe protein in a phenylalanine restricted diet, but its efficacy is rarely studied. We report a multicentre, open, longitudinal, prospective intervention study on a phenylalanine-free infant formula (PKU Start: Vitaflo International Ltd.).

RESULTS

This was a 2-part study: part I (28 days short term evaluation) and part II (12 months extension). Data was collected on infant blood phenylalanine concentrations, dietary intake, growth, and gastrointestinal tolerance. Ten infants (n = 8 males, 80%), with a median age of 14 weeks (range 4-36 weeks) were recruited from 3 treatment centres in the UK. Nine of ten infants completed the 28-day follow-up (one caregiver preferred the usual phenylalanine-free formula and discontinued the study formula after day 14) and 7/9 participated in study part II. The phenylalanine-free infant formula contributed a median of 57% (IQR 50-62%) energy and 53% (IQR 33-66%) of total protein intake from baseline to the end of the part II extension study. During the 12-month follow-up, infants maintained normal growth and satisfactory blood phenylalanine control. Any early gastrointestinal symptoms (constipation, colic, vomiting and poor feeding) improved with time.

CONCLUSION

The study formula was well tolerated, helped maintain good metabolic control, and normal growth in infants with PKU. The long-term efficacy of phenylalanine-free infant formula should continue to be observed and monitored.

Human milk microbial species are associated with infant head-circumference during early and late lactation in Guatemalan mother-infant dyads

Human milk contains abundant commensal bacteria that colonize and establish the infant's gut microbiome but the association between the milk microbiome and head circumference during infancy has not been explored. For this cross-sectional study, head-circumference-for-age-z-scores (HCAZ) of vaginally delivered breastfed infants were collected from 62 unrelated Mam-Mayan mothers living in eight remote rural communities in the Western Highlands of Guatemala during two stages of lactation, 'early' (6-46 days postpartum, n = 29) or 'late' (109-184 days postpartum, n = 33). At each stage of lactation, infants were divided into HCAZ ≥ -1 SD (early: n = 18; late: n = 14) and HCAZ < -1 SD (early: n = 11; late: n = 19). Milk microbiome communities were assessed using 16S ribosomal RNA gene sequencing and DESeq2 was used to compare the differential abundance (DA) of human milk microbiota with infant HCAZ subgroups at both stages of lactations. A total of 503 ESVs annotated 256 putative species across the 64 human milk samples. Alpha-diversity using Chao index uncovered a difference in microbial community richness between HCAZ ≥ -1 SD and HCAZ < -1 SD groups at late lactation (p = 0.045) but not at early lactation. In contrast, Canonical Analysis of Principal Coordinates identified significant differences between HCAZ ≥ -1 SD and HCAZ < -1 SD at both stages of lactation (p = 0.003); moreover, 26 milk microbial taxa differed in relative abundance (FDR < 0.05) between HCAZ ≥ -1 SD and HCAZ < -1 SD, with 13 differentially abundant at each lactation stage. Most species in the HCAZ ≥ -1 SD group were Streptococcus species from the Firmicutes phylum which are considered human colonizers associated with human milk whereas the HCAZ < -1 SD group at late lactation had more differentially abundant taxa associated with environmentally and 'potentially opportunistic' species belonging to the Actinobacteria genus. These findings suggest possible associations between brain growth of breastfed infants and the milk microbiome during lactation. Importantly, these data provide the first evidence of cross talk between the human milk microbiome and the infant brain that requires further investigation.

Extracellular vesicle miRNAs in breast milk of obese mothers

Background

Breast milk has abundant extracellular vesicles (EVs) containing various biological molecules (cargo), including miRNAs. EVs are not degraded in the gastrointestinal system and circulation; thus, breast milk EVs (bEVs) are expected to interact with other organs in breastfed infants and modify the gene expression of recipient cells using miRNAs. Maternal pre-pregnancy BMI is a critical factor influencing the composition of breast milk. Thus, in mothers with obesity, miRNAs in bEVs can be altered, which might be associated with adverse health outcomes in infants. In this study, we examined 798 miRNAs to determine which miRNAs are altered in the bEVs of mothers with obesity and their potential impact on breastfed infants.

Methods

We recruited healthy nursing mothers who were either of normal weight (BMI < 25) or with obesity (BMI ≥ 30) based on their pre-pregnancy BMI, and delivered a singleton baby in the prior 6 months. EVs were isolated from breast milk with ultracentrifugation. bEV characteristics were examined by flow cytometry and fluorescence imaging of EV markers. A total of 798 miRNAs were screened using a NanoString human miRNA panel to find differentially expressed miRNAs in bEVs of mothers with obesity compared to mothers of normal weight.

Results

We included 65 nursing mothers: 47 of normal weight and 18 with obesity based on pre-pregnancy BMI. After bEV isolation, we confirmed the expression of various EV markers. Out of 37 EV markers, CD326 (EpCaM) was the most highly expressed in bEVs. The most abundant miRNAs in bEVs include miR-30b-5p, miR-4454, miR-494-3p, and let-7 miRNAs. Target genes of the top 10 miRNAs were associated with cancer, prolactin pathway, EGFR, ErbB, and FoxO signaling pathway. In bEVs of mothers with obesity, 19 miRNAs were differentially expressed (adjusted p < 0.05 cut-off), which include miR-575, miR-630, miR-642a-3p, and miR-652-5p. These miRNAs and their target genes were associated with neurological diseases and psychological disorders.

Conclusion

In this study, we characterized bEVs and demonstrated altered miRNAs in bEVs of mothers with obesity and identified the pathways of their potential target genes. Our findings will provide insight for future studies investigating the role of bEVs in breastfed infants.

The Occurrence of Squalene in Human Milk and Infant Formula

(1) Background: The aim of the conducted research was to analyze the squalene content in infants' food. (2) Methods: The experimental material included human milk collected from 100 women from Poland and three different infant formulas. The breast milk fat was extracted according to the Rose-Gottlieb method (AOAC), while the squalene content was determined using the high-performance liquid chromatography (HPLC) method. (3) Results: The highest amount of squalene was identified in the milk of women aged 18-25 (p < 0.05), and its content in milk decreased with the age of lactating women. Moreover, the greatest amount of squalene was identified in milk from the first lactation period (colostrum), while in mature milk, its content was more than two times lower. There was a correlation between breastfeeding BMI and the squalene content in milk (r = 0.78). (4) Conclusions: The conducted research shows that the level of squalene in human milk depends on physiological factors such as the lactation period and individual factors (age, BMI). The results of the conducted research indicate that breast milk is richer in squalene than modified milk. This study shows the importance of breastfeeding and indicates the superiority of breast milk over infant formulas.

Correlation of maternal dietary intake with breast milk composition and infant growth

Background: Maternal dietary intake during the period of lactation has an impact on infants growth. Macronutrients in breast milk are affected by several factors such as maternal dietary intake and maternal nutritional status. This study aims to prove the association between maternal protein and fat intake with the composition of breast milk and growth of infants (age 0-6 months). Methods: Prospective study was conducted for 6 months in 41 mother-infant pairs who were exclusively breastfed, and visited to hospitals or health centres. The mothers age is <40 years old with normal and single pregnancy. The breast milk was collected and analyzed using Human Milk Analyzer. Results: There was a negative correlation between maternal protein intake and breast milk composition at 3 months old infants (p = 0.042), between fat intake with HAZ score at 2 weeks (p = 0.048), and between protein intake with HAZ score at 3 months (p = 0.049). Finally, there was a significant increase in WAZ and HAZ score in all sample groups. Although the maternal protein intake of our subjects were only at 83% of Indonesian's RDA average, the protein composition of breast milk and the growth of the infants was sufficient. Conclusion: There is correlation between maternal dietary intake with the composition of breastmilk and infant growth. Even though the calories and protein intake of the mother is lower than the RDA, the breast milk is still sufficient for the growth of infants aged 0-6 months who are exclusively breastfed.

Urine Metabolomic Profile of Breast- versus Formula-Fed Neonates Using a Synbiotic-Enriched Formula

The aim of this study was to compare the urine metabolic fingerprint of healthy neonates exclusively breastfed with that of neonates fed with a synbiotic-enriched formula (Rontamil^® Complete 1) at four time points (the 3rd and 15th days of life and the 2nd and 3rd months). The determination of urine metabolic fingerprint was performed using NMR metabolomics. Multivariate data analyses were performed with SIMCA-P 15.0 software and R language. Non-distinct profiles for both groups (breastfeeding and synbiotic formula) for the two first time points (3rd and 15th days of life) were detected, whereas after the 2nd month of life, a discrimination trend was observed between the two groups, which was further confirmed at the 3rd month of life. A clear discrimination of the synbiotic formula samples was evident when comparing the metabolites taken in the first days of life (3rd day) with those taken in the 2nd and 3rd months of life. In both cases, OPLS-DA models explained more than 75% of the metabolic variance. Non-distinct metabolomic profiles were obtained between breastfed and synbiotic-formula-fed neonates up to the 15th day of life. Discrimination trends were observed only after the 2nd month of the study, which could be attributed to breastfeeding variations and the consequent dynamic profile of urine metabolites compared to the stable ingredients of the synbiotic formula.

Exploring the Potential of Human Milk and Formula Milk on Infants’ Gut and Health

Early-life gut microbiota plays a role in determining the health and risk of developing diseases in later life. Various perinatal factors have been shown to contribute to the development and establishment of infant gut microbiota. One of the important factors influencing the infant gut microbial colonization and composition is the mode of infant feeding. While infant formula milk has been designed to resemble human milk as much as possible, the gut microbiome of infants who receive formula milk differs from that of infants who are fed human milk. A diverse microbial population in human milk and the microbes seed the infant gut microbiome. Human milk contains nutritional components that promote infant growth and bioactive components, such as human milk oligosaccharides, lactoferrin, and immunoglobulins, which contribute to immunological development. In an attempt to encourage the formation of a healthy gut microbiome comparable to that of a breastfed infant, manufacturers often supplement infant formula with prebiotics or probiotics, which are known to have a bifidogenic effect and can modulate the immune system. This review aims to elucidate the roles of human milk and formula milk on infants’ gut and health.

Fatty Acid Composition of Milk from Mothers with Normal Weight, Obesity, or Gestational Diabetes

Gestation and the neonatal period are crucial periods in infant development. Many components of breast milk, including fatty acids, play an important role in strengthening the immune system. The aim of our research was to evaluate the fatty acid profiles of milk from 69 mothers, including subjects having a normal weight, obesity, or gestational diabetes. For the analyses, we used gas chromatography (GC) with flame ionization detection (FID) and GC coupled with mass spectrometry (GC/MS). The main fatty acids found in breast milk were palmitic acid (C16:0; 26-28%), linoleic acid (C18:2; 23-28%), and α-linolenic acid linoleic acid (C18:3; 15-17%), followed by myristic acid (C14:0; 5-8%), lauric acid (C12:0; 4-6%) and stearic acid (C18:0; 4-5%). The average breakdown of fatty acids was 50% saturated, 44% polyunsaturated, and 6% monounsaturated. Breast milk samples were classified using principal component analysis and linear discriminant analysis. Results showed that milk from the two major groups of obese and normal body mass index (BMI) could be distinguished with an accuracy of 89.66%. Breast milk samples of Hungarian and Ukrainian mothers showed significant differences based on the fatty acid composition, which variations are attributable to the mothers' dietary habits.

Milk microbiomes of three great ape species vary among host species and over time

In mammalian neonates, milk consumption provides nutrients, growth factors, immune molecules, and microbes. Milk microbiomes are increasingly recognized for their roles in seeding infant gut microbiomes and priming immune development. However, milk microbiome variation within and among individuals remains under investigation. We used 16S rRNA gene sequencing to investigate factors shaping milk microbiomes in three captive great ape species: Gorilla gorilla gorilla (individuals, N = 4; samples, n = 29), Pongo abelii (N = 2; n = 16), and Pongo pygmaeus (N = 1; n = 9). We demonstrate variation among host species, over lactation, and between housing facilities. In phylogenetic community composition, milk microbiomes were distinct among the three ape species. We found only a few shared, abundant bacterial taxa and suggest that they likely serve functional roles. The diversity and community composition of milk microbiomes showed gradual changes over time in gorillas and the Bornean orangutan, which was detectable with our comprehensive sampling over lactation stages (> 300-day span). In gorillas, milk microbiomes differed between housing facilities, but were similar between dams within a facility. These results support the strong influence of evolutionary history in shaping milk microbiomes, but also indicate that more proximate cues from mother, offspring, and the environment affect the distribution of rarer microbial taxa.

Literature Review of Mothers Diagnosed With COVID-19 and the Impact on Breastfeeding Their Newborns

In early 2020, newborns were separated from their mothers who were diagnosed with COVID-19 infection. The purpose of this literature review is to examine the current evidence to determine if the transmission of COVID-19 infection to the neonate increases if newborns are directly breastfed by mothers who are positive for COVID-19 infection. There were 28 studies conducted in seven countries, with 10 of those studies conducted in the United States. In total, 5,123 neonates were born to mothers diagnosed with COVID-19, with 3,872 neonates determined to have been breastfed or provided mixed feeding including breast milk. Overall, 2.35% (91/3,872) of the newborns tested positive, and all recovered from COVID-19 infection. As frontline health care providers, nurses are instrumental in offering support and education on the risks and benefits of breastfeeding for individuals diagnosed with COVID-19.

Enteral Nutrition: The Intricacies of Human Milk from the Immune System to the Microbiome

In 2012, the American Academy of Pediatrics stated that all preterm infant diets should consist of human milk (mother's own milk or pasteurized donor human milk). The clinical reasons supporting this policy are many, including reducing infections and retinopathy of prematurity, decreased neonatal intensive care unit length of stay, subsequent readmissions, a decrease in mortality, and improved neurodevelopmental outcomes. This article focuses on human milk, its composition and bioactive factors, and how it affects the gut-brain axis through the microbiome. We examine how differences between mother's own milk and pasteurized donor human milk affect the premature infant.

Breast milk-derived extracellular vesicle miRNAs are associated with maternal asthma and atopy

Background: Breast milk-derived extracellular vesicle (EV) miRNAs may program child health outcomes associated with maternal asthma and atopy. The authors investigated associations between maternal asthma/atopy and EV miRNAs in the Programming of Intergenerational Stress Mechanisms cohort. Methods: Breast milk-derived EV miRNAs collected 6.1 ± 5.9 weeks postnatally (n = 80 mothers) were profiled using the TaqMan OpenArray Human MicroRNA Panel. The authors assessed associations using adjusted robust regression. Results: Nine EV miRNAs were associated with asthma during pregnancy (a priori criteria: nominal p < 0.05; |B_regression| >0.2). miR-1290 was associated with asthma and atopy during pregnancy (p < 0.05; |B_regression| >0.2). Enriched Kyoto Encyclopedia of Genes and Genomes pathways included TGF-β signaling and extracellular matrix-receptor interaction (false discovery rate <0.05). Conclusion: In this study, maternal asthma and atopy were associated with breast milk-derived EV miRNAs. Additional studies are needed to understand whether EV miRNAs have direct effects on infant and child health.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Breast Milk and the Importance of Chrononutrition

During pregnancy the human fetus receives timed cues from the circadian rhythms of temperature, metabolites, and hormones from the mother. This influence is interrupted after parturition, the infant does not secrete melatonin and their circadian rhythms are still immature. However, evolution provided the solution to this problem. The newborn can continue receiving the mother's timed cues through breastmilk. Colostrum, transitional, and mature human milk are extraordinary complex biofluids that besides nutrients, contain an array of other non-nutritive components. Upon birth the first milk, colostrum, is rich in bioactive, immunological factors, and in complex oligosaccharides which help the proper establishment of the microbiome in the gut, which is crucial for the infants' health. Hormones, such as glucocorticoids and melatonin, transfer from the mother's plasma to milk, and then the infant is exposed to circadian cues from their mother. Also, milk components of fat, proteins, amino acids, and endogenous cannabinoids, among others, have a markedly different concentration between day and night. In the present review, we give an overview of nutritive and non-nutritive components and their daily rhythms in human milk and explore their physiological importance for the infant. Finally, we highlight some interventions with a circadian approach that emphasize the importance of circadian rhythms in the newborn for their survival, proper growth, and development. It is estimated that ~600,000 deaths/year are due to suboptimal breastfeeding. It is advisable to increase the rate of exclusive breastfeeding, during the day and night, as was established by the evolution of our species.

Survey on the Status of Breastfeeding in Korean Medical Institution Workers

BACKGROUND

Human breast milk is essential and provides irreplaceable nutrients for early humans. However, breastfeeding is not easy for various reasons in medical institution environments. Therefore, in order to improve the breastfeeding environment, we investigated the difficult reality of breastfeeding through questionnaire responses from medical institution workers.

METHODS

A survey was conducted among 179 medical institution workers with experience in childbirth within the last five years. The survey results of 175 people were analyzed, with incoherent answers excluded.

RESULTS

Of the 175 people surveyed, a total of 108 people (61.7%) worked during the day, and 33 people (18.9%) worked in three shifts. Among 133 mothers who stayed with their babies in the same nursing room, 111 (93.3%) kept breastfeeding for more than a month, but among those who stayed apart, only 10 (71.4%) continued breastfeeding for more than a month (P = 0.024). Ninety-five (88.0%) of daytime workers, 32 (94.1%) two-shift workers, and 33 (100%) three-shift workers continued breastfeeding for more than a month (P = 0.026). Workers in general hospitals tended to breastfeed for significantly longer than those that worked in tertiary hospitals (P = 0.003). A difference was also noted between occupation categories (P = 0.019), but a more significant difference was found in the comparison between nurses and doctors (P = 0.012). Longer breastfeeding periods were noted when mothers worked three shifts (P = 0.037). Depending on the period planned for breastfeeding prior to childbirth, the actual breastfeeding maintenance period after birth showed a significant difference (P = 0.002). Of 112 mothers who responded to the question regarding difficulties in breastfeeding after returning to work, 87 (77.7%) mentioned a lack of time caused by being busy at work, 82 (73.2%) mentioned the need for places and appropriate circumstances.

CONCLUSION

In medical institutions, it is recommended that environmental improvements in medical institutions, the implementation of supporting policies, and the provision of specialized education on breastfeeding are necessary to promote breastfeeding.

Etiological and pathophysiological enigmas of severe coronavirus disease 2019, multisystem inflammatory syndrome in children, and Kawasaki disease

During the coronavirus disease 2019 (COVID-19) pandemic, a novel multisystem inflammatory syndrome in children (MIS-C) has been reported worldwide since the first cases were reported in Europe in April 2020. MIS-C is temporally associated with severe acute respiratory syndrome coronavirus 2 infection and shows Kawasaki disease (KD)-like features. The epidemiological and clinical characteristics in COVID-19, KD, and MIS-C differ, but severe cases of each disease share similar clinical and laboratory findings such as a protracted clinical course, multiorgan involvement, and similar activated biomarkers. These findings suggest that a common control system of the host may act against severe disease insult. To solve the enigmas, we proposed the protein-homeostasis-system hypothesis in that every disease involves etiological substances and the host's immune system controls them by their size and biochemical properties. Also, it is proposed that the etiological agents of KD and MIS-C might be certain strains in the microbiota of human species and etiological substances in severe COVID-19, KD, and MIS-C originate from pathogen-infected cells. Since disease severity depends on the amounts of inflammation-inducing substances and corresponding immune activation in the early stage of the disease, an early proper dose of corticosteroids and/or intravenous immunoglobulin (IVIG) may help reduce morbidity and possibly mortality among patients with these diseases. Corticosteroids are low cost and an analogue of host-origin cortisol among immune modulators. This study's findings will help clinicians treating severe COVID-19, KD, and MIS-C, especially in developing countries, where IVIG and biologics supplies are insufficient.

Maternal Vitamin D Status Correlates to Leukocyte Antigenic Responses in Breastfeeding Infants

It is unknown if vitamin D (vitD) sufficiency in breastfeeding mothers can lead to physiological outcomes for their children that are discernible from infant vitD sufficiency per se. In a 3-month, randomized vitD supplementation study of mothers and their exclusively breastfeeding infants, the effects of maternal vitD sufficiency were determined on infant plasma concentrations of 25-hydroxyvitamin D (i.e., vitD status) and 11 cytokines. An inverse correlation was seen between maternal vitD status and infant plasma TNF concentration (r = −0.27; p < 0.05). Infant whole blood was also subjected to in vitro antigenic stimulation. TNF, IFNγ, IL-4, IL-13, and TGFβ1 responses by infant leukocytes were significantly higher if mothers were vitD sufficient but were not as closely correlated to infants’ own vitD status. Conversely, IL-10 and IL-12 responses after antigenic challenge were more correlated to infant vitD status. These data are consistent with vitD-mediated changes in breast milk composition providing immunological signaling to breastfeeding infants and indicate differential physiological effects of direct-infant versus maternal vitD supplementation. Thus, consistent with many previous studies that focused on the importance of vitD sufficiency during pregnancy, maintenance of maternal sufficiency likely continues to affect the health of breastfed infants.

Antiviral properties of whey proteins and their activity against SARS-CoV-2 infection

Native and chemically modified whey proteins and their peptide derivatives are encountering the interest of nutraceutical and pharmaceutical industries, due to the numerous properties, ranging from antimicrobial to immunological and antitumorigenic, that result in the possibility to employ milk and its protein components in a wide range of treatment and prevention strategies. Importantly, whey proteins were found to exert antiviral actions against different enveloped and non-enveloped viruses. Recently, the scientific community is focusing on these proteins, especially lactoferrin, since in vitro studies have demonstrated that they exert an important antiviral activity also against SARS-CoV-2. Up-to date, several studies are investigating the efficacy of lactoferrin and other whey proteins in vivo. Aim of this review is to shed light on the most relevant findings concerning the antiviral properties of whey proteins and their potential applications in human health, focussing on their application in prevention and treatment of SARS-CoV-2 infection.

Breast milk components and factors that may affect lactation success

Introduction. Breastfeeding is the most important way to feed a newborn, infant and a young child. Lactogenesis is the ability of secreting milk from the mammary gland and includes secretory initiation and activation. The birth of the placenta and decrease in progesterone levels stimulate an increase in prolactin levels and the secretion of milk from the breast. Human milk contains carbohydrates, lipids, proteins, vitamins, minerals, fatty acids, amino acids and trace elements. In addition, numerous cells, macrophages, bacteria, chemokines, cytokines, immunoglobulins, hormones, growth factors, and mucin are present. The composition of milk differs depending on the phase of secretion. Colostrum is secreted for the first five days after birth, then comes transitional milk, and mature milk two weeks after birth. During the very act of breastfeeding, there is a difference between pre-milk and last milk. In pre-milk, the fat content is low and increases with the duration of lactation, and in breast milk it is relatively high. Aim: To point out the importance of milk composition and factors that are influential for breastfeeding. Conclusion: Maternal parity, age or socioeconomic status and education can affect the concentration of certain components of breast milk. Adequate social policy and support, along with education related to early breastfeeding experiences, can be the key factors in initiating and maintaining breastfeeding. Besides the mother and the child, the entire social community would benefit from that.

Breastfeeding Practices and Determinant Factors of Exclusive Breastfeeding among Mothers of Children Aged 0-23 Months in Northwestern Romania

In terms of breastfeeding (BF) practices in Romania, there is a lack of up-to-date data. The aim of the present study was to assess current BF practices, and to investigate the factors associated with exclusive BF (EBF) under 6 months of age in northwestern Romania. A structured questionnaire was used to collect data among 1399 mothers of children aged 0-23 months, recruited between March and June 2019, from the community. BF practices were evaluated based on the World Health Organization indicators for assessing infant and young child feeding practices, whereas determinants of EBF were explored using logistic regression models. Almost all mothers (95.7%) breastfed their child at least once. The EBF rate was 46.7%, the continued BF rate at one year of age was 54.2%, and the continued BF rate at 2 years of age was 30.3%. The place of delivery and parental leave duration were strong determinants of EBF. The improving rates observed in this study for all the BF practices assessed suggest the continuation of efforts to develop effective national policies and programs for promoting, protecting, and supporting BF in Romania. Particular emphasis should be given to the creation in maternity hospitals of an environment that is supportive towards breastfeeding.

lncRNA NORAD is consistently detected in breastmilk exosomes and its expression is downregulated in mothers of preterm infants

Breast milk is the ideal food for infants and undoubtedly has immediate and long-term benefits. Breast milk contains extracellular vesicles (EVs) i.e., exosomes secreted by maternal breast cells. Exosomes carry genetic material, such as long non-coding RNAs (lncRNAs), which possibly participate in cell-to-cell communications, as they are known to regulate critical gene pathways. The aim of the present study was to screen human breastmilk exosomes for their lncRNA cargo and to examine exosomal lncRNA levels associated with milk obtained from mothers that gave birth at term or prematurely (<37 weeks of gestation). Samples were collected at 3 weeks postpartum from 20 healthy, breastfeeding mothers; 10 mothers had given birth at full-term and 10 mothers preterm. Exosomal RNA was extracted from all samples and the expression of 88 distinct lncRNAs was determined using reverse transcription-quantitative PCR. A total of 13 lncRNAs were detected in ≥85% of the samples, while 31 were detected in ≥50% of the samples. Differential expression analysis of the lncRNAs between the two groups revealed ≥2-fold differences, with generally higher lncRNA concentrations found in the milk of the mothers that gave birth at term compared with those that gave birth preterm. Among these, the non-coding RNA activated at DNA damage (NORAD) was prominently detected in both groups, and its expression was significantly downregulated in the breast milk exosomes of mothers who delivered preterm. On the whole, the present study demonstrates that breast milk lncRNAs may be important factors of normal early human development. Collectively, the presence of lncRNAs in human breast milk may explain the consistent inability of researchers to fully 'humanize' animal milk.

Human milk microbes: Strategies to improve delivery to the infant

Mother's own milk provides personalized nutrition and immune protection to the developing infant. The presence of healthy microbes plays an important role in the infant's gut by programming the microbiota and excluding potential pathogens. This review describes the important components in mother's own milk that contribute to its superiority for infant nutrition and suggest potential strategies to replicate these factors in alternative feedings when sufficient milk is unavailable. Current strategies to supplement, substitute and replicate mother's own milk including microbial restoration, use of unpasteurized donor human milk, probiotics and fortification are discussed. Critical work remains to be done in understanding the human milk microbiome and metabolome and in improving lactation support for mothers of preterm infants. Increasing delivery of mother's own milk and milk components to infants would likely positively impact infant mortality and health worldwide.

Human Breast Milk Composition and Function in Human Health: From Nutritional Components to Microbiome and MicroRNAs

Human breast milk (HBM) is not only an indispensable source of nutrients for early human growth and development, supplying components that support infant growth and development, but also contains various essential immunologic components with anti-infectious activities and critical roles in the formation of immunity. It is also known that HBM contains its own unique microbiome, including beneficial, commensal, and potentially probiotic bacteria, that can contribute to infant gut colonization. In addition, HBM-derived extracellular vesicles, exosomes, and microRNA are attracting increasing interest for their potential to transfer to the infant and their role in infant development. In this article, we examine some of the various constituents in HBM and review the evidence supporting their associated health effects and their potential applications in human health.

Potential Benefits of Bovine Colostrum in Pediatric Nutrition and Health

Bovine colostrum (BC), the first milk produced from cows after parturition, is increasingly used as a nutritional supplement to promote gut function and health in other species, including humans. The high levels of whey and casein proteins, immunoglobulins (Igs), and other milk bioactives in BC are adapted to meet the needs of newborn calves. However, BC supplementation may improve health outcomes across other species, especially when immune and gut functions are immature in early life. We provide a review of BC composition and its effects in infants and children in health and selected diseases (diarrhea, infection, growth-failure, preterm birth, necrotizing enterocolitis (NEC), short-bowel syndrome, and mucositis). Human trials and animal studies (mainly in piglets) are reviewed to assess the scientific evidence of whether BC is a safe and effective antimicrobial and immunomodulatory nutritional supplement that reduces clinical complications related to preterm birth, infections, and gut disorders. Studies in infants and animals suggest that BC should be supplemented at an optimal age, time, and level to be both safe and effective. Exclusive BC feeding is not recommended for infants because of nutritional imbalances relative to human milk. On the other hand, adverse effects, including allergies and intolerance, appear unlikely when BC is provided as a supplement within normal nutrition guidelines for infants and children. Larger clinical trials in infant populations are needed to provide more evidence of health benefits when patients are supplemented with BC in addition to human milk or formula. Igs and other bioactive factors in BC may work in synergy, making it critical to preserve bioactivity with gentle processing and pasteurization methods. BC has the potential to become a safe and effective nutritional supplement for several pediatric subpopulations.

Immunomodulatory Effects of Human Colostrum and Milk

The immune system is not fully developed in human neonates and infants; breastfeeding is important in this stage as the bioactive components of human breast milk are known to have anti-microbial, anti-inflammatory, and immunomodulatory effects, and can therefore contribute to an infant's immunity against allergies, asthma, autoimmune diseases, and inflammatory bowel disease. Herein, the positive effect on the immune system by human colostrum and milk are reviewed.

Provider recommendations and maternal practices when providing breast milk to children with immunoglobulin E-mediated food allergy

BACKGROUND

There is limited research investigating maternal dietary practices and health care provider recommendations when providing breast milk (BM) to children with immunoglobulin (Ig) E-mediated food allergy.

OBJECTIVE

To explore health care provider recommendations and maternal practices when providing BM to children with IgE-mediated food allergy and to assess for possible IgE-mediated reactions to BM while the mother consumed the food to which her child has allergy.

METHODS

A web-based survey was distributed to breastfeeding (BF) mothers of children with IgE-mediated food allergies. Reported reactions to BM were scored by an allergist, provided only with the details of the possible reaction and not the suspect allergen or route of exposure, as to the likelihood that the reaction was IgE mediated.

RESULTS

A total of 133 mothers completed the survey. After food allergy diagnosis, 47.4% (n = 63) of the mothers reported that they were advised by their health care provider to continue BF without dietary restriction, 17.3% (n = 23) were advised to avoid eating the food(s) their child has allergy to while BF, and in 28.6% (n = 38), this concern was not addressed. A few of the mothers (12%, 16/133) reported that their child experienced an allergic reaction to BM. An allergist evaluated most of these reactions (75%, 12/16) as not likely IgE mediated.

CONCLUSION

This study exposed inconsistent recommendations for mothers providing BM to children with IgE-mediated food allergies. Most mothers were able to consume the food their child has allergy to without adverse sequelae. Standardized, evidence-based recommendations would enhance the well-being of these mother-infant dyads.

The Triad Mother-Breast Milk-Infant as Predictor of Future Health: A Narrative Review

The benefits of human milk for both mother and infant are widely acknowledged. Human milk could represent a link between maternal and offspring health. The triad mother-breast milk-infant is an interconnected system in which maternal diet and lifestyle might have effects on infant's health outcome. This link could be in part explained by epigenetics, even if the underlining mechanisms have not been fully clarified yet. The aim of this paper is to update the association between maternal diet and human milk, pointing out how maternal diet and lifestyle could be associated with breast-milk composition, hence with offspring's health outcome.

The Role of Early Programming and Early Nutrition on the Development and Progression of Celiac Disease: A Review

Experimental and epidemiological evidence has shown that modifications of the intrauterine environment can have deleterious consequences for individuals, expressed as an increased risk of suffering non-communicable pathologies in adult life, which is known as the hypothesis of the early origin of diseases or fetal programming. On the other hand, changes in gene expression patterns through epigenetic modifications can be the basis for long-term maintenance of the effects of fetal programming. In this sense, epigenetics comprises the study of intrauterine disturbances, which develop diseases in the adult, including celiac disease (CD). In addition, early feeding practices could influence the risk of CD development, such as breastfeeding timing and duration and age of gluten introduction in the diet. Gluten acts as a trigger for CD in genetically predisposed subjects, although approximately 30% of the world population has HLA DQ2 or DQ8, the prevalence of the disease is only 1–3%. It is not known what factors act to modify the risk of disease in genetically at-risk subjects. Taking into account all these considerations, the aim of the current review is to elucidate the role of early programming and the effect of early nutrition on the development and progression of CD. It is logical that attention has been paid to gluten as a key element in preventing the disease. However, there is no strong evidence in favor of the protective factor of breastfeeding, timing of introduction of gluten during lactation, and the development of CD. Diet, genetic risk, microbiota, and environmental interaction are possible triggers of the change in tolerance to an immune response to gluten, but large-scale cohort studies are needed. Emerging scientific concepts, such as epigenetics, may help us establish the role of these factors.

Compositional and Functional Comparisons of the Microbiota in the Colostrum and Mature Milk of Dairy Goats

Simple Summary

Our findings revealed significant influences of lactation stage on goat milk microbial and functional composition both in colostrum and mature milk. Microbial communities which were found in colostrum and mature milk could potentially establish goat kids’ gut microbiota and have an influence on the development of microbial components that provide potential health promotion effects in goats.

Abstract

Goat milk is essential for the initial development of kids by providing a great source of commensal bacteria. In this study, we analyzed the microbiota of the milk of 30 healthy Saanen dairy goats. The 30 samples comprised 15 colostrum and 15 mature milk samples, collected from three different farms of Shaanxi Province. Colostrum samples were collected daily for five days post-delivery and mature milk was collected on the 7th, 10th, 20th, 30th, and 40th days. The result showed that microbial alpha diversity was higher in the mature milk compared with that in the colostrum. Linear discriminant analysis effect size (LEfSe) was performed to detect differentially abundant taxa in colostrum and goat milk. According to taxonomy results, Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes were the predominant bacteria phyla in both colostrum and mature milk. In addition, lactation stage noticeably influenced the composition of milk microbiota. Specifically, Novosphingobium, Brachybacterium, Psychrobacter, Lactobacillus, Yersinia, Roseateles, Rothia, Sanguibacter, Cloacibacterium, Variovorax, Sphingobacterium, and Coxiella were enriched in the colostrum, while Georgenia, Peptostreptococcus, Bacteroidales, Yaniella, Planomicrobium, Cloacibacterium, Azospirillum, Turicibacter, Cupriavidus, Herbaspirillum, Rhodobacteraceae, and Aeromonadales were the dominant genera in the mature milk. The enriched metabolic functions of the goat milk microbiota were predicted by PICRUSt and classified by KEGG pathway. Moreover, the abundances of environmental information processing, cellular processes pathway, genetic information processing pathway, organismal systems pathway, and metabolism pathway were significantly different between microbiota of colostrum and mature milk. Altogether, our study disclosed the significant difference between the microbial communities of colostrum and mature milk and provided grounds for further research in dairy microbiology.

Circulating microRNAs in Breast Milk and Their Potential Impact on the Infant

MicroRNAs (MiRNAs) are small RNA molecules that can exert regulatory functions in gene expression. MiRNAs have been identified in diverse tissues and biological fluids, both in the context of health and disease. Breastfeeding has been widely recognized for its superior nutritional benefits; however, a number of bioactive compounds have been found to transcend these well-documented nutritional contributions. Breast milk was identified as a rich source of miRNAs. There has been increasing interest about their potential ability to transfer to the offspring as well as what their specific involvement is within the benefits of breast milk in the infant. In comparison to breast milk, formula milk lacks many of the benefits of breastfeeding, which is thought to be a result of the absence of some of these bioactive compounds. In recent years, the miRNA profile of breast milk has been widely studied, along with the possible transfer mechanisms throughout the infant's digestive tract and the role of miRNA-modulated genes and their potential protective and regulatory functions. Nonetheless, to date, the current evidence is not consistent, as many methodological limitations have been identified; hence, discrepancies exits about the biological functions of miRNAs. Further research is needed to provide thorough knowledge in this field.

More than Nutrition: Therapeutic Potential of Breast Milk-Derived Exosomes in Cancer

Human breast milk (HBM) is an irreplaceable source of nutrition for early infant growth and development. Breast-fed children are known to have a low prevalence and reduced risk of various diseases, such as necrotizing enterocolitis, gastroenteritis, acute lymphocytic leukemia, and acute myeloid leukemia. In recent years, HBM has been found to contain a microbiome, extracellular vesicles or exosomes, and microRNAs, as well as nutritional components and non-nutritional proteins, including immunoregulatory proteins, hormones, and growth factors. Especially, the milk-derived exosomes exert various physiological and therapeutic function in cell proliferation, inflammation, immunomodulation, and cancer, which are mainly attributed to their cargo molecules such as proteins and microRNAs. The exosomal miRNAs are protected from enzymatic digestion and acidic conditions, and play a critical role in immune regulation and cancer. In addition, the milk-derived exosomes are developed as drug carriers for delivering small molecules and siRNA to tumor sites. In this review, we examined the various components of HBM and their therapeutic potential, in particular of exosomes and microRNAs, towards cancer.

Analysis of the human breast milk microbiome and bacterial extracellular vesicles in healthy mothers

The microbiota of human breast milk (HBM) contribute to infant gut colonization; however, whether bacterial extracellular vesicles (EVs) are present in HBM or might contribute to this process remains unknown. In this study, we characterized the HBM microbiota of healthy Korean mothers and measured the key bacteria likely affecting infant gut colonization by analyzing both the microbiota and bacterial EVs. A total of 22 HBM samples were collected from lactating mothers. The DNA of bacteria and bacteria-derived EVs was extracted from each sample. In alpha-diversity analyses, bacterial samples showed higher richness and evenness than bacterial EV samples, and beta-diversity analyses showed significant differences between bacteria and bacterial EVs within identical individual samples. Firmicutes accounted for the largest proportion among the phyla, followed by Proteobacteria, Bacteroidetes, and Actinobacteria, in both bacteria and bacterial EV samples. At the genus level, Streptococcus (25.1%) and Staphylococcus (10.7%) were predominant in bacterial samples, whereas Bacteroides (9.1%), Acinetobacter (6.9%), and Lactobacillaceae(f) (5.5%) were prevalent in bacterial EV samples. Several genera, including Bifidobacterium, were significantly positively correlated between the two samples. This study revealed the diverse bacterial communities in the HBM of healthy lactating mothers, and found that gut-associated genera accounted for a high proportion in bacterial EV samples. Our findings suggest the existence of key bacteria with metabolic activity that are independent of the major bacterial populations that inhabit HBM, and the possibility that EVs derived from these bacteria are involved in the vertical transfer of gut microbiota.