Human milk oligosaccharides are associated with protection against diarrhea in breast-fed infants

Natural anti-adhesive components against pathogenic bacterial adhesion and infection in gastrointestinal tract: case studies of Helicobacter pylori, Salmonella enterica, Clostridium difficile, and diarrheagenic Escherichia coli

Antimicrobial resistance (AMR) poses a global public health concern. Recognizing the critical role of bacterial adhesion in pathogenesis of infection, anti-adhesive therapy emerges as a promising approach to impede initial bacterial attachment, thus preventing pathogenic colonization and infection. Natural anti-adhesive agents derived from food sources are generally safe and have the potential to inhibit the emergence of resistant bacteria. This comprehensive review explored diverse natural dietary components exhibiting anti-adhesive activities against several model enteric pathogens, including Helicobacter pylori, Salmonella enterica, Clostridium difficile, and three key diarrheagenic Escherichia coli (i.e., enterotoxigenic E. coli, enteropathogenic E. coli, and enterohemorrhagic E. coli). Investigating various anti-adhesive products will advance our understanding of current research of the field and inspire further development of these agents as potential nutraceuticals or adjuvants to improve the efficacy of conventional antibiotics.

"OMICS" in Human Milk: Focus on Biological Effects on Bone Homeostasis

Human milk (HM) is a complex biofluid rich in nutrients and bioactive compounds essential for infant health. Recent advances in omics technologies-such as proteomics, metabolomics, and transcriptomics-have shed light on the influence of HM on bone development and health. This review discusses the impact of various HM components, including proteins, lipids, carbohydrates, and hormones, on bone metabolism and skeletal growth. Proteins like casein and whey promote calcium absorption and osteoblast differentiation, supporting bone mineralization. Long-chain polyunsaturated fatty acids like docosahexaenoic acid (DHA) contribute to bone health by modulating inflammatory pathways and regulating osteoclast activity. Additionally, human milk oligosaccharides (HMOs) act as prebiotics, improving gut health and calcium bioavailability while influencing bone mineralization. Hormones present in HM, such as insulin-like growth factor 1 (IGF-1), leptin, and adiponectin, have been linked to infant growth, body composition, and bone density. Research has shown that higher IGF-1 levels in breast milk are associated with increased weight gain, while leptin and adiponectin influence fat mass and bone metabolism. Emerging studies have also highlighted the role of microRNAs (miRNAs) in regulating key processes like adipogenesis and bone homeostasis. Furthermore, microbiome-focused techniques reveal HM's role in establishing a balanced infant gut microbiota, indirectly influencing bone development by enhancing nutrient absorption. Although current findings are promising, comprehensive longitudinal studies integrating omics approaches are needed to fully understand the intricate relationships among maternal diet, HM composition, and infant bone health. Bridging these gaps could offer novel dietary strategies to optimize skeletal health during infancy, advancing early-life nutrition science.

Impact of complementary feeding on infant gut microbiome, metabolites and early development

Introducing complementary foods is critical for promoting infant health and development. During the weaning period, the dietary patterns provide essential nutrients and facilitate the development of a diverse gut microbiome, which plays significant roles in the regulation of immune, metabolic, and neurological functions. This study enrolled 200 families to assess the impact of complementary feeding on infant growth and health outcomes. Data included detailed records of feeding practices, infant growth measurements, health assessments, and fecal samples and breast milk collected between weeks 12 and 32 postpartum. The gut microbiome was analyzed using 16S rRNA sequencing, while metabolites such as human milk oligosaccharides (HMOs), monosaccharides, and short-chain fatty acids (SCFAs) were measured using chromatography-mass spectrometry. Results revealed a high prevalence of breastfeeding, with complementary food introduced at around 16 weeks. Significant alterations in the infant gut microbiome were observed, particularly in the genera Lactobacillus, Akkermansia, and Staphylococcus. Additionally, the levels of HMOs, monosaccharides, and SCFAs were found to be influenced by the introduction of complementary foods. Significant correlations emerged between complementary feeding practices, gut microbiome diversity, specific bacterial genera (e.g., Streptococcus, Lactobacillus, Bifidobacterium, and Clostridioides), and key metabolites (such as lacto-N-tetraose, lacto-N-neotetraose, mannose, and butyric acid). This study offers valuable insights into the complex interactions between complementary feeding, gut microbiome development, and metabolite profiles during early infant growth. Future research with larger cohorts and targeted dietary interventions is recommended to further elucidate the underlying mechanisms.

Iron Absorption from an Iron-Fortified Follow-Up Formula with and without the Addition of a Synbiotic or a Human-Identical Milk Oligosaccharide: A Randomized Crossover Stable Isotope Study in Young Thai Children

BACKGROUND

Previous studies showed that pre- and probiotics may enhance iron absorption. Probiotics combined with prebiotics (synbiotics), including human-identical milk oligosaccharides (HiMOs), are commonly added to infant and follow-up formula (FUF). Whether these additions enhance iron absorption from iron-fortified commercial milk formula is uncertain.

OBJECTIVES

We determined the effect of adding 1) a synbiotic [galacto-oligosaccharide [GOS] + Limosilactobacillus reuteri (L. reuteri)] or 2) the HiMO 2'-fucosyllactose (2'FL) to iron-fortified FUF on iron absorption in young Thai children.

METHODS

In a randomized, controlled, single-blinded (participants) crossover study, 82 Thai children aged 8-14 mo were enrolled to consume single servings (235 mL) of FUF with isotopically labeled ferrous sulfate (2.2 mg iron) with 1) the synbiotic (400 mg/100 mL GOS and L. reuteri DSM 17938), 2) the HiMO 2'FL (100 mg/100 mL), and 3) without synbiotic and 2'FL (control) in random order and a 3-d washout period between administrations. Fractional iron absorption [FIA (%)] was assessed by measuring erythrocyte incorporation of isotopic labels 14 d (n = 26) and 28 d (n = 76) after consumption of the last test FUF.

RESULTS

Median (IQR) FIA from iron-fortified FUF with the synbiotic [8.2 (5.2, 12.9)%] and with 2'FL [8.4 (5.5, 14.1)%] did not differ from the control FUF [8.1 (4.8,14.7)%] (synbiotic compared with control, P = 0.24; 2'FL compared with control, P = 0.95). FIA from all FUF did not differ when measured after 14 and 28 d of erythrocyte incorporation (Time, P = 0.368; FUF, P = 0.435; Time × FUF, P = 0.937). Fecal pH and hemoglobin were negatively associated with FIA.

CONCLUSIONS

In young Thai children, the addition of a synbiotic (GOS + L. reuteri) or 2'FL to iron-fortified FUF did not impact FIA from a single serving. The study was registered at clinicaltrials.gov as NCT04774016.

Human Milk Oligosaccharides and Respiratory Syncytial Virus Infection in Infants

In infants worldwide, respiratory syncytial virus (RSV) is the leading cause of lower respiratory infections, including bronchiolitis, which is a major source of infant mortality. Bronchiolitis is the most common lower respiratory infection and the major cause of hospitalization in the first 6 mo of life. Infant responses to RSV infection are highly diverse, with symptoms varying from asymptomatic or mild to so severe as to require mechanical ventilation. Breastfed infants present a lower incidence and less severe forms of RSV lower respiratory infections. Among the multitude of human milk bioactive compounds, human milk oligosaccharides (hMOSs) are strong candidates for having a protective effect against RSV. hMOS reduces the viral load and the inflammatory signaling in cultured RSV-infected respiratory human cells. In addition to this direct effect, indirect mechanisms, notably gut microbiota composition and metabolism, have been proposed to mediate the protective effect of hMOS. Intake of infant formula containing synthetic hMOS has been shown to increase Bifidobacterium abundance and that of its metabolites, especially acetate, in infant feces and to reduce lower respiratory tract infections during the first year of life. Breastfeeding and the use of hMOS are promising approaches to protect against and treat RSV disease. Here, we review current evidence on the role of hMOS with regard to RSV infection and disease, attending to knowledge gaps and future research directions.

Exploring the diverse biological significance and roles of fucosylated oligosaccharides

Long since, carbohydrates were thought to be used just as an energy source and structural material. However, in recent years, with the emergence of the field of glycobiology and advances in glycomics, much has been learned about the biological role of oligosaccharides, a carbohydrate polymer containing a small number of monosaccharides, in cell-cell interaction, signal transduction, immune response, pathogen adhesion processes, early embryogenesis, and apoptosis. The function of oligosaccharides in these processes is diversified by fucosylation, also known as modification of oligosaccharides. Fucosylation has allowed the identification of more than 100 different oligosaccharide structures that provide functional diversity. ABO blood group and Lewis antigens are among the best known fucosyl-linked oligosaccharides. In addition, the antigens in the ABO system are composed of various sugar molecules, including fucosylated oligosaccharides, and Lewis antigens are structurally similar to ABO antigens but differ in the linkage of sugars. Variation in blood group antigen expression affects the host's susceptibility to many infections. However, altered expression of ABO and Lewis antigens is related with prognosis in carcinoma types. In addition, many pathogens recognize and bind to human tissues using a protein receptor with high affinity for the fucose molecule in glycoconjugates, such as lectin. Fucosylated oligosaccharides also play vital roles during fertilization and early embryogenesis. Learning and memory-related processes such as neurite growth, neurite migration, and synapse formation seen during the development of the brain, which is among the first organs to develop in embryogenesis, are regulated by fucosylated oligosaccharides. In conclusion, this review mentions the vital roles of fucosylated oligosaccharides in biology, drawing attention to their importance in the development of chemical tools to be used in function analysis and the investigation of various therapeutic targets.

Unlocking the mysteries of milk oligosaccharides: Structure, metabolism, and function

Milk oligosaccharides (MOs), complex carbohydrates prevalent in human breast milk, play a vital role in infant nutrition. Serving as prebiotics, they inhibit pathogen adherence, modulate the immune system, and support newborn brain development. Notably, MOs demonstrate significant variations in concentration and composition, both across different species and within the same species. These characteristics of MOs lead to several compelling questions: (i) What distinct beneficial functions do MOs offer and how do the functions vary along with their structural differences? (ii) In what ways do MOs in human milk differ from those in other mammals, and what factors drive these unique profiles? (iii) What are the emerging applications of MOs, particularly in the context of their incorporation into infant formula? This review delves into the structural characteristics, quantification methods, and species-specific concentration differences of MOs. It highlights the critical role of human MOs in infant growth and their potential applications, providing substantial evidence to enhance infant health and development.

Innovative direct introduction-ion mobility-mass spectrometry (DI-IM-MS) approach for fast and robust isomer-specific quantification in a complex matrix: Application to 2'-fucosyllactose (2'-FL) in breast milk

Identification and specific quantification of isomers in a complex biological matrix by mass spectrometry alone is not an easy task due to their identical chemical formula and therefore their same mass-to-charge ratio (m/z). Here, the potential of direct introduction combined with ion mobility-mass spectrometry (DI-IM-MS) for rapid quantification of isomers as human milk oligosaccharides (HMOs) was investigated. Differences in HMO profiles between various analyzed breast milk samples were highlighted using the single ion mobility monitoring (SIM2) acquisition for high ion mobility resolution detection. Furthermore, the Se+ (secretor) or Se- (non-secretor) phenotype could be assigned to breast milk samples studied based on their HMO contents, especially on the response of 2'-fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I). The possibility of quantifying a specific isomer in breast milk by DI-IM-MS was also investigated. The standard addition method allowed the determination of the 2'-FL despite the presence of other oligosaccharides, including 3-fucosyllactose (3-FL) isomer in breast milk. This proof-of-concept study demonstrated the high potential of such an approach for the rapid and convenient quantification of isomers in complex mixtures.

The role of glycans in health and disease: Regulators of the interaction between gut microbiota and host immune system

The human gut microbiota is home to a diverse collection of microorganisms that has co-evolved with the host immune system in which host-microbiota interactions are essential to preserve health and homeostasis. Evidence suggests that the perturbation of this symbiotic host-microbiome relationship contributes to the onset of major diseases such as chronic inflammatory diseases including Inflammatory Bowel Disease. The host glycocalyx (repertoire of glycans/sugar-chains at the surface of gut mucosa) constitutes a major biological and physical interface between the intestinal mucosa and microorganisms, as well as with the host immune system. Glycans are an essential niche for microbiota colonization and thus an important modulator of host-microorganism interactions both in homeostasis and in disease. In this review, we discuss the role of gut mucosa glycome as an instrumental pathway that regulates host-microbiome interactions in homeostasis but also in health to inflammation transition. We also discuss the power of mucosa glycosylation remodelling as an attractive preventive and therapeutic strategy to preserve gut homeostasis.

Microbiota from human infants consuming secretors or non-secretors mothers' milk impacts the gut and immune system in mice

Maternal secretor status is one of the determinants of human milk oligosaccharides (HMOs) composition, which, in turn, influences the gut microbiota composition of infants. To understand if this change in gut microbiota impacts immune cell composition, intestinal morphology, and gene expression, 21-day-old germ-free C57BL/6 mice were transplanted with fecal microbiota from infants whose mothers were either secretors (SMM) or non-secretors (NSM) or from infants consuming dairy-based formula (MFM). For each group, one set of mice was supplemented with HMOs. HMO supplementation did not significantly impact the microbiota diversity; however, SMM mice had a higher abundance of genus Bacteroides, Bifidobacterium, and Blautia, whereas, in the NSM group, there was a higher abundance of Akkermansia, Enterocloster, and Klebsiella. In MFM, gut microbiota was represented mainly by Parabacteroides, Ruminococcaceae_unclassified, and Clostrodium_sensu_stricto. In mesenteric lymph node, Foxp3+ T cells and innate lymphoid cells type 2 were increased in MFM mice supplemented with HMOs, while in the spleen, they were increased in SMM + HMOs mice. Similarly, serum immunoglobulin A was also elevated in MFM + HMOs group. Distinct global gene expression of the gut was observed in each microbiota group, which was enhanced with HMOs supplementation. Overall, our data show that distinct infant gut microbiota due to maternal secretor status or consumption of dairy-based formula and HMO supplementation impacts immune cell composition, antibody response, and intestinal gene expression in a mouse model.

IMPORTANCE

Early life factors like neonatal diet modulate gut microbiota, which is important for the optimal gut and immune function. One such factor, human milk oligosaccharides (HMOs), the composition of which is determined by maternal secretor status, has a profound effect on infant gut microbiota. However, how the infant gut microbiota composition determined by maternal secretor status or consumption of infant formula devoid of HMOs impacts infant intestinal ammorphology, gene expression, and immune signature is not well explored. This study provides insights into the differential establishment of infant microbiota derived from infants fed by secretor or non-secretor mothers milk or those consuming infant formula and demonstrates that the secretor status of mothers promotes Bifidobacteria and Bacteroides sps. establishment. This study also shows that supplementation of pooled HMOs in mice changed immune cell composition in the spleen and mesenteric lymph nodes and immunoglobulins in circulation. Hence, this study highlights that maternal secretor status has a role in infant gut microbiota composition, and this, in turn, can impact host gut and immune system.

Recent Progress in Human Milk Oligosaccharides and Its Antiviral Efficacy

Gastrointestinal (GI)-associated viruses, including rotavirus (RV), norovirus (NV), and enterovirus, usually invade host cells, transmit, and mutate their genetic information, resulting in influenza-like symptoms, acute gastroenteritis, encephalitis, or even death. The unique structures of human milk oligosaccharides (HMOs) enable them to shape the gut microbial diversity and endogenous immune system of human infants. Growing evidence suggests that HMOs can enhance host resistance to GI-associated viruses but without a systematic summary to review the mechanism. The present review examines the lactose- and neutral-core HMOs and their antiviral effects in the host. The potential negative impacts of enterovirus 71 (EV-A71) and other GI viruses on children are extensive and include neurological sequelae, neurodevelopmental retardation, and cognitive decline. However, the differences in the binding affinity of HMOs for GI viruses are vast. Hence, elucidating the mechanisms and positive effects of HMOs against different viruses may facilitate the development of novel HMO derived oligosaccharides.

Antimicrobial Properties of Colostrum and Milk

The growing number of antibiotic resistance genes is putting a strain on the ecosystem and harming human health. In addition, consumers have developed a cautious attitude towards chemical preservatives. Colostrum and milk are excellent sources of antibacterial components that help to strengthen the immunity of the offspring and accelerate the maturation of the immune system. It is possible to study these important defenses of milk and colostrum, such as lactoferrin, lysozyme, immunoglobulins, oligosaccharides, etc., as biotherapeutic agents for the prevention and treatment of numerous infections caused by microbes. Each of these components has different mechanisms and interactions in various places. The compound's mechanisms of action determine where the antibacterial activity appears. The activation of the antibacterial activity of milk and colostrum compounds can start in the infant's mouth during lactation and continue in the gastrointestinal regions. These antibacterial properties possess potential for therapeutic uses. In order to discover new perspectives and methods for the treatment of bacterial infections, additional investigations of the mechanisms of action and potential complexes are required.

Epidemiology of group A rotavirus in children under five years of age with gastroenteritis in N'Djamena, Chad

BACKGROUND

Group A Rotaviruses (RVA) is one of the most common causes of severe diarrhoea in infants and children under 5 years of age. Unlike many countries in the world where RVA surveillance/control is active, in Chad , there is currently no applied RVA immunization program and surveillance strategy. The present study aims to determine the prevalence and associated risk factors of RVA gastroenteritis among children under five years of age in N'Djamena.

METHOD

This study comprised two parts: (1) A cross-sectional study carried in four hospitals in N'Djamena between August and November 2019, to determine infection risk factors and evidence of RVA infection among children aged five and below, consulted or hospitalized for diarrhea. An ELISA based RVA VP6 protein detection was used to determine RVA infection prevalence. Infection results and sociodemographic data were statistically analysed to determine RVA infection risk factors. (2) A retrospective study that consisted of analysing the records of stool examinations of the period from January 2016 to December 2018, to determine the prevalence of infectious gastroenteritis among the target population.

RESULTS

For the cross-sectional study, RVA infection prevalence was 12.76% (18/141) with males (61.11%) being more affected (sex ratio: 1.57). Children below 12 months were the most affected age group (44.44%) and 44.4% were malnourished. The mean Vesikari score shows that 38.8% of children have a high severity level and 41.1% have a moderate level. For the retrospective study, 2,592 cases of gastroenteritis hospitalization were analysed; 980 out of 2,592 cases (37.81%) of hospitalization due to diarrhoea were due to diarrhoeagenic pathogens including Emtamoeba hystolitica, Gardia lamblia, Trichomonas hominis, Hymenolepis nana, Escherichia coli, Shigella spp, Proteus mirabilis, and Klebsiella oxytoca. Cases of diarrhoea with negative pathogen search were 1,612 cases (62.19%). The diarrhoea peak was observed during the dry seasons, and the age group under 11 months was the most affected was (57.3%).

CONCLUSION

This study describes the evidence of RVA infection among diarrhoeic children below five years of age in N'Djamena, thus indicates a serious health burden. Malnourishment younger age was the higher risk factor. Further studies are needed to determine the circulating strains prior to considering introduction of RVA vaccine and setup a routine rotavirus surveillance in Chad.

Rational Design of an α-1,3-Fucosyltransferase for the Biosynthesis of 3-Fucosyllactose in Bacillus subtilis ATCC 6051a via De Novo GDP-l-Fucose Pathway

3-Fucosyllactose (3-FL) is an important oligosaccharide and nutrient in breast milk that can be synthesized in microbial cells by α-1,3-fucosyltransferase (α-1,3-FucT) using guanosine 5'-diphosphate (GDP)-l-fucose and lactose as substrates. However, the catalytic efficiency of known α-1,3-FucTs from various sources was limited due to their low solubility. To enhance the microbial production of 3-FL, the efficiencies of α-1,3-FucTs were evaluated and in Bacillus subtilis (B. subtilis) chassis cells that had been endowed with a heterologous synthetic pathway for GDP-l-fucose, revealing that the activity of FucTa from Helicobacter pylori (H. pylori) was higher than that of any of other reported homologues. To further improve the catalytic performance of FucTa, a rational design approach was employed, involving intracellular evaluation of the mutational sites of M32 obtained through directed evolution, analysis of the ligand binding site diversity, and protein structure simulation. Among the obtained variants, the FucTa-Y218 K variant exhibited the highest 3-FL yield, reaching 7.55 g/L in the shake flask growth experiment, which was 3.48-fold higher than that achieved by the wild-type enzyme. Subsequent fermentation optimization in a 5 L bioreactor resulted in a remarkable 3-FL production of 36.98 g/L, highlighting the great prospects of the designed enzyme and the strains for industrial applications.

Is the impact of paid maternity leave policy on the prevalence of childhood diarrhoea mediated by breastfeeding duration? A causal mediation analysis using quasi-experimental evidence from 38 low-income and middle-income countries

OBJECTIVES

Quasi-experimental evidence suggests that extending the duration of legislated paid maternity leave is associated with lower prevalence of childhood diarrhoea in low-income and middle-income countries (LMICs). This could be due to a variety of mechanisms. This study examines whether this effect is mediated by changes in breastfeeding duration.

DESIGN AND SETTING

Difference-in-difference approach and causal mediation analysis were used to perform secondary statistical analysis of cross-sectional data from Demographic and Health Surveys (DHSs) in 38 LMICs.

PARTICIPANTS

We merged longitudinal data on national maternity leave policies with information on childhood diarrhoea related to 639 153 live births between 1996 and 2014 in 38 LMICs that participated in the DHS at least twice between 1995 and 2015.

PRIMARY OUTCOME MEASURE

Our outcome was whether the child had bloody stools in the 2 weeks prior to the interview. This measure was used as an indicator of severe diarrhoea because the frequency of loose stools in breastfed infants can be difficult to distinguish from pathological diarrhoea based on survey data.

RESULTS

A 1-month increase in the legislated duration of paid maternity leave was associated with a 34% (risk ratio 0.66, 95% CI 0.47 to 0.91) reduction in the prevalence of bloody diarrhoea. Breast feeding for at least 6 months and 12 months mediated 10.6% and 7.4% of this effect, respectively.

CONCLUSION

Extending the duration of paid maternity leave appears to lower diarrhoea prevalence in children under 5 years of age in LMICs. This effect is slightly mediated by changes in breastfeeding duration.

Human Milk Oligosaccharides: A Critical Review on Structure, Preparation, Their Potential as a Food Bioactive Component, and Future Perspectives

Human milk is the gold standard for infant feeding. Human milk oligosaccharides (HMOs) are a unique group of oligosaccharides in human milk. Great interest in HMOs has grown in recent years due to their positive effects on various aspects of infant health. HMOs provide various physiologic functions, including establishing a balanced infant's gut microbiota, strengthening the gastrointestinal barrier, preventing infections, and potential support to the immune system. However, the clinical application of HMOs is challenging due to their specificity to human milk and the difficulties and high costs associated with their isolation and synthesis. Here, the differences in oligosaccharides in human and other mammalian milk are compared, and the synthetic strategies to access HMOs are summarized. Additionally, the potential use and molecular mechanisms of HMOs as a new food bioactive component in different diseases, such as infection, necrotizing enterocolitis, diabetes, and allergy, are critically reviewed. Finally, the current challenges and prospects of HMOs in basic research and application are discussed.

Human breast milk: A promising treatment for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disorder occurring in newborns, with a mortality rate ranging from 20 % to 30 %. The existing therapeutic approaches for NEC are limited in their effectiveness. Various factors contribute to the development of NEC, including disruption of barrier function, dysregulation of the intestinal immune system, and abnormal colonization of the intestinal microbiota. Researchers have shown considerable interest in exploring the therapeutic potential of the constituents present in human breast milk (HBM) for treating NEC. HBM contains numerous bioactive components, such as exosomes, growth factors, and oligosaccharides. However, the precise mechanisms by which HBM exerts its protective effects against NEC remain incompletely understood. In this study, our objective was to comprehensively review the bioactive substances present in HBM, aiming to facilitate the development of novel therapeutic strategies for NEC.

The function of human milk oligosaccharides and their substitute oligosaccharides as probiotics in gut inflammation

Gut inflammation seriously affects the healthy life of patients, and has a trend of increasing incidence rate. However, the current methods for treating gut inflammation are limited to surgery and drugs, which can cause irreversible damage to patients, especially infants. As natural oligosaccharides in human breast milk, human milk oligosaccharides (HMOs) function as probiotics in treating and preventing gut inflammation: improving the abundance of the gut microbiota, increasing the gut barrier function, and reducing the gut inflammatory reaction. Meanwhile, due to the complexity and high cost of their synthesis, people are searching for functional oligosaccharides that can replace HMOs as a food additive in infants milk powder and adjuvant therapy for chronic inflammation. The purpose of this review is to summarize the therapeutic and preventive effects of HMOs and their substitute functional oligosaccharides as probiotics in gut inflammation, and to summarize the prospect of their application in infant breast milk replacement in the future.

Association between adherence to a low carbohydrate dietary (LCD) pattern with breast milk characteristics and oxidative markers in infants' urine: a cross-sectional study

BACKGROUND

Breast milk (BM) is a dynamic fluid that varies over time and between women. The variations in BM components are most likely associated with maternal diet quality. This study aimed to assess adherence to a low carbohydrate dietary (LCD) pattern with oxidative stress markers of BM characteristics and infants' urine.

MATERIALS AND METHODS

In this cross-sectional study 350 breastfeeding mothers and their infants were recruited. BM samples were collected from mothers, and urine specimens were obtained from each infant. To evaluate LCD scores, subjects were divided into 10 deciles according to the percent of energy obtained from carbohydrates, proteins, and fats. Determination of total antioxidant activity was conducted using the ferric reducing antioxidant power (FRAP), 2, 2'-diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid reactive substances (TBARs), and Ellman's assay. Biochemical assays of samples including calcium, total protein, and triglyceride level were also performed using commercial kits.

RESULTS

Participants with the greatest LCD pattern adherence were placed into the last quartile (Q4), and those with the minimum LCD were in the first quartile (Q1). Individuals in the highest LCD quartile had significantly higher levels of milk FRAP, thiol, and protein, as well as infant urinary FRAP and lower milk MDA levels than those in the lowest quartile. Multivariate linear regression analyses indicated that higher score of the LCD pattern was associated with a higher level of milk thiol, protein, and lower level of milk MDA (p < 0.05).

CONCLUSION

Our findings show that adherence to a LCD, as defined by a low level of carbohydrates in daily food intake, is linked with improved BM quality and markers of oxidative stress in infant urine.

Determinants of human milk oligosaccharides profiles of participants in the STRONG kids 2 cohort

Introduction

Human milk oligosaccharides (HMOS) are indigestible carbohydrates that support infant development by establishing a healthy microbiota, preventing infectious diseases, and promoting immune and cognitive development. Individual HMOS have distinct functions based on their chemical structures. HMO profiles can vary largely among mothers, but the research on factors other than genetic background affecting HMO composition are limited.

Methods

In the present analysis, we examined the relationships between maternal characteristics and the HMO profiles of breastfeeding mothers (n = 392) in the STRONG kids 2 with the following demographic characteristics: average age: 30.8 y, 74.5% White, and 75.5% exclusively breastfeeding. Human milk samples were collected at 6 weeks postpartum and maternal information was obtained from self-reported surveys. Information on dietary intake changes since the participants have been breastfeeding was collected. HMO profiles were analyzed by high performance liquid chromatography coupled with mass spectrometry and secretor status was determined by the presence of four secretor markers [2′-fucosyllactose (2′-FL), LNFP I, LDFT, and TFLNH]. Spearmen correlation test was utilized to determine the relationships between individual HMOS and associations with maternal factors. Between-group differences in HMO relative abundances were examined with Kruskal-Wallis test.

Results

Among all participants, 71.9% were secretors and 28.1% were non-secretors. The relative abundances of all HMOS differed (p &lt; 0.05) by secretor status, with the exception for 6′-SL and 3′-SL. Positive correlations were observed among HMOS with similar structures, such as the 1,2-fucosylated HMOS. The abundances of selected HMOS were associated with maternal body weight, pregnancy complications, and dietary characteristics. Based on pre-pregnancy BMI, in all mothers, relative abundance of 3′-SL was significantly higher in overweight mothers than obese mothers (p = 0.013). In milk produced by non-secretor mothers, LNPF I + III abundances were greater in overweight than normal weight mothers (p = 0.020). Several HMO abundances were found to be associated with Gestational diabetes mellitus (GDM). Variations of HMO abundances were also observed with dietary food intake. In all mothers, egg consumption was positively correlated with LNT + LNnT (R = 0.13; p = 0.012) and cheese intake was positively associated with 2′-FL (R = 0.10; p = 0.046) and S-LNnH II (R = 0.11; p = 0.026) abundances.

Discussion

HMO profiles were found to be associated with maternal characteristics and intake. Future research will investigate associations between HMOS and maternal and infant outcomes.

Necrotizing enterocolitis in premature infants-A defect in the brakes? Evidence from clinical and animal studies

A key aspect of postnatal intestinal adaptation is the establishment of symbiotic relationships with co-evolved gut microbiota. Necrotizing enterocolitis (NEC) is the most severe disease arising from failure in postnatal gut adaptation in premature infants. Although pathological activation of intestinal Toll-like receptors (TLRs) is believed to underpin NEC pathogenesis, the mechanisms are incompletely understood. We postulate that unregulated aberrant TLR activation in NEC arises from a failure in intestinal-specific mechanisms that tamponade TLR signaling (the brakes). In this review, we discussed the human and animal studies that elucidate the developmental mechanisms inhibiting TLR signaling in the postnatal intestine (establishing the brakes). We then evaluate evidence from preclinical models and human studies that point to a defect in the inhibition of TLR signaling underlying NEC. Finally, we provided a framework for the assessment of NEC risk by screening for signatures of TLR signaling and for NEC prevention by TLR-targeted therapy in premature infants.

Effects of probiotic and synbiotic supplementation on ponderal and linear growth in severely malnourished young infants in a randomized clinical trial

Severe acute malnutrition (SAM) is a major global public health problem. We aimed to assess the effects of probiotic and synbiotic supplementation on rate of weight gain and change in length in young SAM infants. This study was substudy of a single-blind randomized clinical trial (NCT0366657). During nutritional rehabilitation, 67 <6 months old SAM infants were enrolled and randomized to receive either probiotic (Bifidobacterium. infantis EVC001) or synbiotic (B. infantis EVC001 + Lacto-N-neotetraose [LNnT]) or placebo (Lactose) for four weeks and were followed for four more weeks after supplementation. In multivariable linear regression model, the mean rate of weight gain in the probiotic arm compared to placebo was higher by 2.03 unit (P < 0.001), and 1.13 unit (P = 0.030) in the synbiotic arm. In linear mixed-effects model, mean WAZ was higher by 0.57 unit (P = 0.018) in probiotic arm compared to placebo. Although not statistically significant, delta length for age z score (LAZ) trended to be higher among children in probiotc (β = 0.25) and synbiotic (β = 0.26) arms compared to placebo in multivariable linear regression model. Our study describes that young SAM infants had a higher rate of weight gain when supplemented with probiotic alone, compared to their counterparts with either synbiotic or placebo.

Necrotizing enterocolitis, gut microbes, and sepsis

Necrotizing enterocolitis (NEC) is a devastating disease in premature infants and the leading cause of death and disability from gastrointestinal disease in this vulnerable population. Although the pathophysiology of NEC remains incompletely understood, current thinking indicates that the disease develops in response to dietary and bacterial factors in the setting of a vulnerable host. As NEC progresses, intestinal perforation can result in serious infection with the development of overwhelming sepsis. In seeking to understand the mechanisms by which bacterial signaling on the intestinal epithelium can lead to NEC, we have shown that the gram-negative bacterial receptor toll-like receptor 4 is a critical regulator of NEC development, a finding that has been confirmed by many other groups. This review article provides recent findings on the interaction of microbial signaling, the immature immune system, intestinal ischemia, and systemic inflammation in the pathogenesis of NEC and the development of sepsis. We will also review promising therapeutic approaches that show efficacy in pre-clinical studies.

The role of breastfeeding as a protective factor against the development of the immune-mediated diseases: A systematic review

INTRODUCTION

Breast milk is rich in nutrients and immunological factors capable of protecting infants against various immunological diseases and disorders. The current systematic review has been framed with the objective of studying the role of breastfeeding as a protective factor against the development of immune-mediated diseases.

METHODS

The database and website searches were performed using PubMed, PubMed Central, Nature, Springer, Nature, Web of Science, and Elsevier. The studies were scrutinized based on the nature of participants and the nature of disease considered. The search was restricted to infants with immune-mediated diseases such as diabetes mellitus, allergic conditions, diarrhoea, and rheumatoid arthritis.

RESULTS

We have included 28 studies, out of which seven deal with diabetes mellitus, two rheumatoid arthritis, five studies about Celiac Disease, twelve studies about allergic/ asthma/wheezing conditions and one study on each of the following diseases: neonatal lupus erythematosus and colitis.

DISCUSSION

Based on our analysis, breastfeeding in association with the considered diseases was found to be positive. Breastfeeding is involved as protective factor against various diseases. The role of breastfeeding in the prevention of diabetes mellitus has been found to be significantly higher than for other diseases.

Functional effects of human milk oligosaccharides (HMOs)

Human milk oligosaccharides (HMOs) are the third most important solid component in human milk and act in tandem with other bioactive components. Individual HMO levels and distribution vary greatly between mothers by multiple variables, such as secretor status, race, geographic region, environmental conditions, season, maternal diet, and weight, gestational age and mode of delivery. HMOs improve the gastrointestinal barrier and also promote a bifidobacterium-rich gut microbiome, which protects against infection, strengthens the epithelial barrier, and creates immunomodulatory metabolites. HMOs fulfil a variety of physiologic functions including potential support to the immune system, brain development, and cognitive function. Supplementing infant formula with HMOs is safe and promotes a healthy development of the infant revealing benefits for microbiota composition and infection prevention. Because of limited data comparing the effect of non-human oligosaccharides to HMOs, it is not known if HMOs offer an additional clinical benefit over non-human oligosaccharides. Better knowledge of the factors influencing HMO composition and their functions will help to understand their short- and long-term benefits.

The Choice of Product for Mixed or Formula Feeding of Infant: Beneficial Properties of Goat’s Milk Formula

This review summarizes the benefits of goat’s milk as the basis to produce adapted milk formulas according to relevant infants feeding issues. The characteristics of main nutrients of modern goat’s milk formulas are presented. A balanced protein composition enriched with β-palmitate, presence of prebiotics-oligosaccharides, natural nucleotides and probiotics advances these formulas closer to breast milk and provide their multipotent sanogenetic effects. The unique composition of goat’s milk formulas allows to ensure normal physical growth of a baby, induces tissue and systemic immunity via adequate intestinal microbiota formation, maintains normal functioning of gut-brain axis, that promotes vegetative and visceral disorders (due to functional digestive disorders) correction. Thus, it is possible to recommend goat’s milk formulas in cases of forced mixed or formula feeding of healthy infants and children with functional digestive disorders.

Safety of 2'-fucosyllactose (2'-FL) produced by a derivative strain (APC199) of Corynebacterium glutamicumATCC 13032 as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 2'-fucosyllactose (2'-FL) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 2'-FL, but it also contains d-lactose, l-fucose, 3-fucosyllactose, difucosyllactose, d-glucose and d-galactose. The NF is produced by fermentation with a genetically modified strain (APC199) of Corynebacterium glutamicum ATCC 13032. 2'-FL, when chemically synthesised or produced by fermentation with derivative strains of Escherichia coli K-12 DH1 or E. coli BL21 (DE3), is already authorised and included in the EU list of NFs. This application refers to a change in the production process and specifications, while target population, conditions of use and consequently, the anticipated intake remain unchanged. The information provided on the identity, production process, composition and specifications of the NF does not raise safety concerns. The intake of other carbohydrate-type compounds structurally related to 2'-FL is also considered of no safety concern. In line with other milk oligosaccharides that are natural components of human milk, the safety assessment of this NF is mainly based on the comparison between the intake of breastfed infants and the estimated intake as NF. Given that the NF would be consumed at the same extent as the already authorised 2'-FL, the Panel considers that the consumption of the NF at the proposed uses and use levels does not raise safety concerns. The Panel concludes that the NF is safe under the proposed conditions of use.

Human Milk Oligosaccharides as Potential Antibiofilm Agents: A Review

Surface-associated bacterial communities called biofilms are ubiquitous in nature. Biofilms are detrimental in medical settings due to their high tolerance to antibiotics and may alter the final pathophysiological outcome of many healthcare-related infections. Several innovative prophylactic and therapeutic strategies targeting specific mechanisms and/or pathways have been discovered and exploited in the clinic. One such emerging and original approach to dealing with biofilms is the use of human milk oligosaccharides (HMOs), which are the third most abundant solid component in human milk after lactose and lipids. HMOs are safe to consume (GRAS status) and act as prebiotics by inducing the growth and colonization of gut microbiota, in addition to strengthening the intestinal epithelial barrier, thereby protecting from pathogens. Moreover, HMOs can disrupt biofilm formation and inhibit the growth of specific microbes. In the present review, we summarize the potential of HMOs as antibacterial and antibiofilm agents and, hence, propose further investigations on using HMOs for new-age therapeutic interventions.

Comparison of twelve human milk oligosaccharides in mature milk from different areas in China in the Chinese Human Milk Project (CHMP) study

Human milk oligosaccharides (HMOs) act as a vital role in the development of infant's gut microbiome and immune function. This study aimed to measure 12 oligosaccharides in milk from Chinese donors (n = 203), and evaluated the influences of multiple factors on the HMOs profiles. The results indicated that concentrations of 6'-sialyllactose were the highest among 12 oligosaccharides (2.31 ± 0.81 g/L). HMOs concentrations varied depending on geographical location. Latitude was observed to be related to concentrations of Lacto-N-neohexaose, lacto-N-fucopentaose III, 3'-sialyllactose (r = -0.67, r = +0.63 and r = +0.50, respectively). Environmental factors like seasons correlated with lacto-N-difucohexaose Ⅱ, Lacto-N-neohexaose and 2'-fucosyllactose (r = -0.47, r = -0.4, r = -0.35, respectively). Several HMOs concentrations were correlated with maternal diet. As a consequence, the HMOs profiles measured were influenced by geographical, environmental, maternal anthropometric as well as dietary factors.

The Potential Role of Human Milk Oligosaccharides in Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is the most common gastrointestinal (GI) disorder in Western populations and therefore a major public health/economic concern. However, despite extensive research, psychological and physiological factors that contribute to the aetiology of IBS remain poorly understood. Consequently, clinical management of IBS is reduced to symptom management through various suboptimal options. Recent evidence has suggested human milk oligosaccharides (HMOs) as a potential therapeutic option for IBS. Here, we review literature concerning the role of HMOs in IBS, including data from intervention and in vitro trials. HMO supplementation shows promising results in altering the gut microbiota and improving IBS symptoms, for instance by stimulating bifidobacteria. Further research in adults is required into HMO mechanisms, to confirm the preliminary results available to date and recommendations of HMO use in IBS.

Human milk nutritional composition across lactational stages in Central Africa

The African region encompasses the highest undernutrition burden with the highest neonatal and infant mortality rates globally. Under these circumstances, breastfeeding is one of the most effective ways to ensure child health and development. However, evidence on human milk (HM) composition from African women is scarce. This is of special concern, as we have no reference data from HM composition in the context of food insecurity in Africa. Furthermore, data on the evolution of HM across lactational stages in this setting lack as well. In the MITICA study, we conducted a cohort study among 48 Central-African women and their 50 infants to analyze the emergence of gut dysbiosis in infants and describe the mother-infant transmission of microbiota between birth and 6 months of age. In this context, we assessed nutritional components in HM of 48 lactating women in Central Africa through five sampling times from week 1 after birth until week 25. Unexpectedly, HM-type III (Secretor + and Lewis genes -) was predominant in HM from Central African women, and some nutrients differed significantly among HM-types. While lactose concentration increased across lactation periods, fatty acid concentration did not vary significantly. The overall median level of 16 detected individual human milk oligosaccharides (HMOs; core structures as well as fucosylated and sialylated ones) decreased from 7.3 g/l at week 1 to 3.5 g/l at week 25. The median levels of total amino acids in HM dropped from 12.8 mg/ml at week 1 to 7.4 mg/ml at week 25. In contrast, specific free amino acids increased between months 1 and 3 of lactation, e.g., free glutamic acid, glutamine, aspartic acid, and serine. In conclusion, HM-type distribution and certain nutrients differed from Western mother HM.

Glucose metabolism and glycosylation link the gut microbiota to autoimmune diseases

Carbohydrates serve as important energy sources and structural substances for human body as well as for gut microbes. As evidenced by the advances in immunometabolism, glucose metabolism and adenosine triphosphate (ATP) generation are deeply involved in immune cell activation, proliferation, and signaling transduction as well as trafficking and effector functions, thus contributing to immune response programming and assisting in host adaption to microenvironment changes. Increased glucose uptake, aberrant expression of glucose transporter 1 (e.g., GLU1), and abnormal glycosylation patterns have been identified in autoimmunity and are suggested as partially responsible for the dysregulated immune response and the modification of gut microbiome composition in the autoimmune pathogenesis. The interaction between gut microbiota and host carbohydrate metabolism is complex and bidirectional. Their impact on host immune homeostasis and the development of autoimmune diseases remains to be elucidated. This review summarized the current knowledge on the crosstalk of glucose metabolism and glycosylation in the host with intestinal microbiota and discussed their possible role in the development and progression of autoimmune diseases. Potential therapeutic strategies targeting glucose metabolism and glycosylation in modulating gut ecosystem and treating autoimmune diseases were discussed as well.

Infant formulas with synthetic oligosaccharides and respective marketing practices

Human milk contains more than 150 different oligosaccharides, which together are among to the quantitatively predominant solid components of breast milk. The oligosaccharide content and composition of human milk show large inter-individual differences. Oligosaccharide content is mostly influenced by genetic variants of the mother's secretor status. Oligosaccharides in human milk are utilized by infants' intestinal bacteria, affecting bacterial composition and metabolic activity. Maternal secretor status, and respective differing fucosylated oligosaccharide content, has been associated both with reduced and increased risk of infection in different populations of breastfed infants, possibly due to environmental conditions and the infant's genotype. There are no safety concerns regarding the addition of previously approved oligosaccharides to infant formula; however, no firm conclusions can be drawn about clinically relevant benefits either. Therefore, infant formulas with synthetic oligosaccharide additives are currently not preferentially recommended over infant formulas without such additives. We consider the use of terms such as "human milk oligosaccharides" and corresponding abbreviations such as "HMO" in any advertising of infant formula to be an inappropriate idealization of infant formula. Manufacturers should stop this practice, and such marketing practices should be prevented by responsible supervisory authorities. Pediatricians should inform families that infant formulas supplemented with synthetic oligosaccharides do not resemble the complex oligosaccharide composition of human milk.

Clinical importance of immunonutrition in infants: a review of the recent literature

During the last decades, the role of nutrition has been well elucidated in medicine, especially among critically ill infants and children. Many nutrients have the potential to modulate the immune system. A healthy immune system is essential for the prevention and recovery of many pediatric illnesses. Intervention using specific nutrients for the immune system is called immunonutrition. Immunonutrient supplementation has been attempted to modulate inflammatory or immune responses, leading to an improved clinical course of critically ill patients with prolonged nutritional supplementation parenterally or enterally. This review discusses immunomodulatory nutrients for infants based on the recent literature.

Human Milk Oligosaccharides Impact Cellular and Inflammatory Gene Expression and Immune Response

Human milk harbors complex carbohydrates, including human milk oligosaccharides (HMOs), the third most abundant component after lactose and lipids. HMOs have been shown to impact intestinal microbiota, modulate the intestinal immune response, and prevent pathogenic bacterial binding by serving as decoy receptors. However, the direct effect of HMOs on intestinal function and immunity remains to be elucidated. To address this knowledge gap, 21-day-old germ-free mice (C57BI/6) were orally gavaged with 15 mg/day of pooled HMOs for 7 or 14 days and euthanized at day 28 or 35. A set of mice was maintained until day 50 to determine the persistent effects of HMOs. Control groups were maintained in the isolators for 28, 35, or 50 days of age. At the respective endpoints, intestinal tissues were subjected to histomorphometric and transcriptomic analyses, while the spleen and mesenteric lymph nodes (MLNs) were subjected to flow cytometric analysis. The small intestine (SI) crypt was reduced after HMO treatment relative to control at days 28 and 35, while the SI villus height and large intestine (LI) gland depth were decreased in the HMO-treated mice relative to the control at day 35. We report significant HMO-induced and location-specific gene expression changes in host intestinal tissues. HMO treatment significantly upregulated genes involved in extracellular matrix, protein ubiquitination, nuclear transport, and mononuclear cell differentiation. CD4+ T cells were increased in both MLNs and the spleen, while CD8+ T cells were increased in the spleen at day 50 in the HMO group in comparison to controls. In MLNs, plasma cells were increased in HMO group at days 28 and 35, while in the spleen, only at day 28 relative to controls. Macrophages/monocytes and neutrophils were lower in the spleen of the HMO group at days 28, 35, and 50, while in MLNs, only neutrophils were lower at day 50 in the 14-day HMO group. In addition, diphtheria toxoid and tetanus toxoid antibody-secreting cells were higher in HMO-supplemented group compared to controls. Our data suggest that HMOs have a direct effect on gastrointestinal tract metabolism and the immune system even in the absence of host microbiota.

Babies, Bugs, and Barriers: Dietary Modulation of Intestinal Barrier Function in Early Life

The intestinal barrier is essential in early life to prevent infection, inflammation, and food allergies. It consists of microbiota, a mucus layer, an epithelial layer, and the immune system. Microbial metabolites, the mucus, antimicrobial peptides, and secretory immunoglobulin A (sIgA) protect the intestinal mucosa against infection. The complex interplay between these functionalities of the intestinal barrier is crucial in early life by supporting homeostasis, development of the intestinal immune system, and long-term gut health. Exclusive breastfeeding is highly recommended during the first 6 months. When breastfeeding is not possible, milk-based infant formulas are the only safe alternative. Breast milk contains many bioactive components that help to establish the intestinal microbiota and influence the development of the intestinal epithelium and the immune system. Importantly, breastfeeding lowers the risk for intestinal and respiratory tract infections. Here we review all aspects of intestinal barrier function and the nutritional components that impact its functionality in early life, such as micronutrients, bioactive milk proteins, milk lipids, and human milk oligosaccharides. These components are present in breast milk and can be added to milk-based infant formulas to support gut health and immunity. Expected final online publication date for the Annual Review of Nutrition, Volume 42 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Association of human milk oligosaccharides and nutritional status of young infants among Bangladeshi mother-infant dyads

Human milk oligosaccharides (HMOs) support the development of a healthy gut microbiome and the growth of infants. We aimed to determine the association of different HMOs with severe acute malnutrition (SAM) among Bangladeshi young infants. This study was nested within a single-blind, randomized, pilot clinical trial (NCT0366657). A total of 45 breastmilk samples from mothers of < 6 months old infants who had SAM (n = 26) or were non-malnourished (n = 19) and were analyzed for constituent HMOs. Of the infants with SAM, 14 (53.85%) had secretor mothers, and 11 (57.89%) of the non-malnourished infants had secretor mothers. A one-unit increase in the relative abundance of sialylated HMOs was associated with higher odds of SAM in age and sex adjusted model (aOR = 2.00, 90% CI 1.30, 3.06), in age, sex, and secretor status adjusted model (aOR = 1.96, 90% CI 1.29, 2.98), and also in age and sex adjusted model among non-secretor mothers (aOR = 2.86, 90% CI 1.07, 7.62). In adjusted models, there was no evidence of a statistically significant association between SAM and fucosylated or undecorated HMOs. Our study demonstrates that a higher relative abundance of sialylated HMOs in mothers’ breastmilk may have a negative impact on young infants’ nutritional status.

Weighted analysis of 2'-fucosylactose, 3-fucosyllactose, lacto-N-tetraose, 3'-sialyllactose, and 6'-sialyllactose concentrations in human milk

Over 150 human milk oligosaccharides (HMOs) have been identified and their concentrations in human milk vary depending on Secretor and Lewis blood group status, environmental and geographical factors, lactation stage, gestational period, and maternal health. Quantitation of HMOs in human milk has been the focus of numerous studies, however, comprehensive and weighted statistical analyses of their levels in human milk are lacking. Therefore, weighted means, standard deviations, medians, interquartile ranges, and 90th percentiles for 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3-FL), lacto-N-tetraose (LNT), 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL) were calculated using random sampling and the levels of these HMOs in human milk reported in the literature. Probability distributions of the reported levels were also constructed. Although the levels reported in the published studies varied, the weighted means for 2'-FL, 3-FL, LNT, 3'-SL, and 6'-SL were calculated to be 2.58, 0.57, 0.94, 0.28, and 0.39 g/L, respectively, which are consistent with those that have been previously determined in other systematic analyses. Likely due to the use of weighting, the 90th percentiles were greater than the 95% confidence limits that have been previously calculated. Our study therefore provides accurate and important statistical data to help support the level of appropriate HMO supplementation in infant formula.

Safety and efficacy of a probiotic-containing infant formula supplemented with 2'-fucosyllactose: a double-blind randomized controlled trial

BACKGROUND

Human milk oligosaccharides (HMOs) have important and diverse biological functions in early life. This study tested the safety and efficacy of a starter infant formula containing Limosilactobacillus (L.) reuteri DSM 17938 and supplemented with 2'-fucosyllactose (2'FL).

METHODS

Healthy infants < 14 days old (n = 289) were randomly assigned to a bovine milk-based formula containing L. reuteri DSM 17938 at 1 × 10⁷ CFU/g (control group; CG) or the same formula with added 1.0 g/L 2'FL (experimental group; EG) until 6 months of age. A non-randomized breastfed group served as reference (BF; n = 60). The primary endpoint was weight gain through 4 months of age in the formula-fed infants. Secondary endpoints included additional anthropometric measures, gastrointestinal tolerance, stooling characteristics, adverse events (AEs), fecal microbiota and metabolism, and gut immunity and health biomarkers in all feeding groups.

RESULTS

Weight gain in EG was non-inferior to CG as shown by a mean difference [95% CI] of 0.26 [-1.26, 1.79] g/day with the lower bound of the 95% CI above the non-inferiority margin (-3 g/day). Anthropometric Z-scores, parent-reported stooling characteristics, gastrointestinal symptoms and associated behaviors, and AEs were comparable between formula groups. Redundancy analysis indicated that the microbiota composition in EG was different from CG at age 2 (p = 0.050) and 3 months (p = 0.052), approaching BF. Similarly, between sample phylogenetic distance (weighted UniFrac) for BF vs EG was smaller than for BF vs CG at 3-month age (p = 0.045). At age 1 month, Clostridioides difficile counts were significantly lower in EG than CG. Bifidobacterium relative abundance in EG tracked towards that in BF. Fecal biomarkers and metabolic profile were comparable between CG and EG.

CONCLUSION

L. reuteri-containing infant formula with 2'FL supports age-appropriate growth, is well-tolerated and may play a role in shifting the gut microbial pattern towards that of breastfed infants.

TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov ( NCT03090360 ) on 24/03/2017.

The Mediating Role of the Gut Microbiota in the Physical Growth of Children

Gut microbiota succession overlaps with intensive growth in infancy and early childhood. The multitude of functions performed by intestinal microbes, including participation in metabolic, hormonal, and immune pathways, makes the gut bacterial community an important player in cross-talk between intestinal processes and growth. Long-term disturbances in the colonization pattern may affect the growth trajectory, resulting in stunting or wasting. In this review, we summarize the evidence on the mediating role of gut microbiota in the mechanisms controlling the growth of children.

Recent understanding of human milk oligosaccharides in establishing infant gut microbiome and roles in immune system

Human milk oligosaccharides (HMOs) are complex sugars with distinctive structural diversity present in breast milk. HMOs have various functional roles to play in infant development starting from establishing the gut microbiome and immune system to take it up to the mature phase. It has been a major energy source for human gut microbes that confer positive benefits on infant health by directly interacting through intestinal cells and generating short-chain fatty acids. It has recently become evident that each species of Bifidobacterium and other genera which are resident of the infant gut employ distinct molecular mechanisms to capture and digest diverse structural HMOs to avoid competition among themselves and successfully maintain gut homeostasis. HMOs also directly modulate gut immune responses and can decoy receptors of pathogenic bacteria and viruses, inhibiting their binding on intestinal cells, thus preventing the emergence of a disease. This review provides a critical understanding of how different gut bacteria capture and utilize selective sugars from the HMO pool and how different structural HMOs protect infants from infectious diseases.

The relationship between human milk, a functional nutrient, and microbiota

The intestinal microbiota begins to take shape in the mother's womb, changes depending on many factors. It is known that the intestinal microbiota has an important role in the maturation of the immune system, also in the prevention of diseases that occur in newborn, childhood, adulthood. Nutrition is the main factor on the development of microbiota in infants after birth. The microbiota compositions of breastfed infants are different from formula-fed infants. Breast milk oligosaccharides play an important role in the development of infants' microbiota. The higher number of Bifidobacterium species and lower α and β diversity in breastfed infants are considered protective. A dysbiosis occurring in the microbiota can cause adverse effects on health. Human milk oligosaccharides also have protective effects on the microbiota. These protective effects are to promote the growth of intestinal microbiota, prevent the adhesion of viruses to the colon, promote the growth of Bifidobacterium with its prebiotic effect. Short-chain fatty acids resulting from their digestion, also have protective effects. Another component that shapes the gut microbiota is HM glycoproteins. The aim of this study is to examine the effect of breast milk on the development of microbiota, to present the results by scanning the literature.

Elucidating the Fragmentation Mechanism of Protonated Lewis A Trisaccharide using MSn CID

Lewis blood group antigens are a prominent example of isomeric oligosaccharides with biological activity. Understanding the fragmentation mechanism in the gas phase is essential for their identification and assignment by mass spectrometric methods such as ESI-MS. In this work, the [M + H]⁺ species of Lewis A trisaccharide and Lewis A trisaccharide methyl glycoside were studied by ESI-MS with FT-ICR as mass analyzer with respect to their fragmentation mechanism. The comparison between the underivatized and the methylated species has shown that the reducing end plays a key role in this mechanism. The results of this study question the existence of Z-type fragment ions after activation of the protonated species. The main product of the fragmentation are Y-type fragment ions and a combination of Y-type fragmentation and the loss of water at the reducing end instead of Z-type fragmentation. C-type fragment ions could not be detected. MS³ measurements also reveal that each fragment ion only occurs with the participation of a mobile proton and the possibility of glycosidic bond cleavage after fragmentation has already occurred at the reducing end as B₂ fragment ion.

A one-year study of human milk oligosaccharide profiles in the milk of healthy UK mothers and their relationship to maternal FUT2 genotype

Human milk oligosaccharides (HMOs) are indigestible carbohydrates with prebiotic, pathogen decoy and immunomodulatory activities that are theorized to substantially impact infant health. The objective of this study was to monitor HMO concentrations over 1 year to develop a long-term longitudinal dataset. HMO concentrations in the breast milk of healthy lactating mothers of the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF) were measured at birth, 2 weeks, 6 weeks, 3 months, 6 months and 12 months postpartum. HMO quantification was conducted by high-performance anion-exchange chromatography with pulsed amperometric detection using a newly validated "dilute-and-shoot" method. This technique minimizes sample losses and expedites throughput, making it particularly suitable for the analysis of large sample sets. Varying patterns of individual HMO concentrations were observed with changes in lactation timepoint and maternal secretor status, with the most prominent temporal changes occurring during the first 3 months. These data provide valuable information for the development of human milk banks in view of targeted distribution of donor milk based on infant age. Maternal FUT2 genotype was determined based on identification at single-nucleotide polymorphism rs516246 and compared with the genotype expected based on phenotypic markers in the HMO profile. Surprisingly, two mothers genotyped as secretors produced milk that displayed very low levels of 2'-fucosylated moieties. This unexpected discrepancy between genotype and phenotype suggests that differential enzyme expression may cause substantial variation in HMO profiles between genotypically similar mothers, and current genotypic methods of secretor status determination may require validation with HMO markers from milk analysis.

Associations of Human Milk Oligosaccharides With Otitis Media and Lower and Upper Respiratory Tract Infections up to 2 Years: The Ulm SPATZ Health Study

Background: Human milk oligosaccharides (HMOs) support and concurrently shape the neonatal immune system through various mechanisms. Thereby, they may contribute to lower incidence of infections in infants. However, there is limited evidence on the role of individual HMOs in the risk of otitis media (OM), as well as lower and upper respiratory tract infections (LRTI and URTI, respectively) in children up to 2 years.

Objective: To investigate whether individual HMO concentrations measured at 6 weeks of lactation were associated with risk of OM, LRTI or URTI up to 2 years in breastfed infants. Associations with OM, LRTI and URTI were determined for the most prominent human milk oligosaccharides including 13 neutral, partly isomeric structures (trioses up to hexaoses), two acidic trioses, and lactose.

Design: HMO measurements and physician reported data on infections were available from human milk samples collected at 6 weeks postpartum (n = 667). Associations of HMOs with infections were assessed in crude and adjusted models using modified Poisson regression.

Results: Absolute concentrations (median [min, max], in g/L) of 2′-fucosyllactose (2′-FL) tended (p = 0.04) to be lower, while lacto-N-tetraose (LNT) was higher in the milk for infants with OM in the 1st year of life (p = 0.0046). In the milk of secretor mothers, LNT was significantly higher in the milk for infants with OM (RR [95% CI]: 0.98 [0.15, 2.60]) compared to infants without OM (RR [95% CI]: 0.76 [0.14, 2.90]) at 1 year (p = 0.0019). No statistically significant milk group differences and associations were observed for OM, LRTI, and URTI (p > 0.0031).

Conclusion: Our findings suggest that neither prominent neutral individual HMOs (ranging from 2′-FL to LNDFHs) nor acidic human milk sialyllactoses or lactose are significantly associated with a reduced or increased risk of infections in infants up to 2 years of age. Further research is needed to determine whether specific HMOs could potentially reduce the incidence or alleviate the course of distinct infections in early life.