Functional effects of human milk oligosaccharides (HMOs)

Breastfeeding decreases the risk of developing psoriasis through to early adulthood

BACKGROUND

Psoriasis is a genetically determined systemic skin disease, although environmental trigger factors are required for disease manifestation. Some of these triggers, such as stress, infections and drug exposure, have been identified.

OBJECTIVES

To explore the role of early nutrition as a risk factor for the development of psoriasis.

METHODS

Parents in the All Babies in Southeast Sweden (ABIS) prospective birth cohort (n = 16 415) answered questionnaires at birth and when their children were aged 1 and 3 years. A diagnosis of psoriasis was determined from the Swedish National Patient Register and National Drug Prescription Register. Statistical analyses were conducted using custom-written R scripts.

RESULTS

Individuals breastfed for < 4 months and who received infant formula before 4 months of age had a higher risk of psoriasis [odds ratio (OR) 1.84 (P = 0.02) and OR 1.88 (P = 0.02), respectively]. At the 3-year follow-up, the increased consumption of fish, especially from the Baltic Sea, increased the risk of psoriasis (OR 9.61; P = 0.003). In addition, the risk of psoriasis increased following the consumption of a large volume of milk (OR 2.53; P = 0.04).

CONCLUSIONS

Our study underscores, for the first time, the impact of very early nutrition on the manifestation of psoriasis through early adulthood. Exclusive breastfeeding for 4 months appears to be protective.

The Role of Maternal Secretor Status and Human Milk Oligosaccharides on Early Childhood Development: A Systematic Review and Meta-Analysis

Background: Breast milk is the gold standard of infant nutrition, delivering nutrients and bioactive molecules as needed to support optimal infant growth and cognitive development. Increasing evidence links human milk oligosaccharides (HMOs) to these early childhood development milestones. Aims: To summarize and synthesize the evidence relating to HMOs and infant brain development, physical growth, and cognitive development. In addition, HMO concentrations in secretor and nonsecretor mothers were compared via a meta-analysis. Study Design: A systematic review and meta-analysis were carried out in accordance with the PRISMA statement. This review used three databases (PubMed, Scopus, and Web of Science) and was limited to English-language articles published between 2000 and June 30, 2023. Results: The initial searches yielded 245 articles, 27 of which were included in the systematic review and 12 in the meta-analysis. The meta-analysis revealed a substantial between-study heterogeneity, I2 = 97.3%. The pooled effect was 0.21 (95% CI: -0.41 to 0.83; p = 0.484), indicating that secretors had higher HMO concentrations, although this difference was not statistically significant. At one month of age, 2'FL, 3FL, and 3'SL play an important role in brain maturation and thus play a critical role in cognitive development. Secretors produce higher concentrations of 2'FL and 3'SL, explaining the benefits to infants of secretor mothers. Growth velocity was correlated to fucosylated and sialylated HMO concentrations, with lower concentrations linked to stunting. Conclusions: According to evidence from the systematically reviewed articles, HMOs are essential for a child's early development, but the extent to which they have an impact depends on maternal secretor status.

Patterns of Human Milk Oligosaccharides in Mature Milk Are Associated with Certain Gut Microbiota in Infants

Human milk oligosaccharides (HMOs) are complexes that play a crucial role in shaping the early-life gut microbiota. This study intends to explore whether HMO patterns are associated with the gut microbiota of infants. We included 96 Chinese breastfeeding mother-infant dyads. Breast milk and infant faecal samples were collected and tested. With milk 2'-fucosyllactose, difucosyllactose, and lacto-N-fucopentaose-I as biomarkers, we divided the mothers into secretor and non-secretor groups. HMO patterns were extracted using principal component analysis. The majority (70.7%) of mothers were categorised as secretor and five different HMO patterns were identified. After adjustment, the infants of secretor mothers exhibited a lower relative abundance of Bifidobacterium bifidum (β = -0.245, 95%CI: -0.465~-0.025). An HMO pattern characterised by high levels of 3-fucosyllactose, lacto-N-fucopentaose-III, and lacto-N-neodifucohexaose-II was positively associated with the relative abundance of Bifidobacterium breve (p = 0.014), while the pattern characterised by lacto-N-neotetraose, 6'-sialyllactose, and sialyllacto-N-tetraose-b was negatively associated with Bifidobacterium breve (p = 0.027). The pattern characterised by high levels of monofucosyl-lacto-N-hexaose-III and monofucosyl-lacto-N-neohexaose was positively associated with Bifidobacterium dentium (p = 0.025) and Bifidobacterium bifidum (p < 0.001), respectively. This study suggests that HMO patterns from mature breast milk were associated with certain gut microbiota of breastfed infants.

Human Milk-The Biofluid That Nourishes Infants from the First Day of Life

Human milk is a biofluid with a unique composition among mammalian milks. Besides this milk's major components, its bioactive compounds, like hormones, immune factors, and oligosaccharides, are unique and important for infant growth and development. The best form of nutrition for term and preterm infants is the mother's own milk. However, in the absence of the mother's own milk, donor milk should be made available. Milk banks support neonatal intensive care units by providing preterm infants with human milk that generally has reasonable nutritive value for this sensitive population. However, neither mother's own milk nor donor milk has sufficient energy content for the growth of preterm babies, so adequate human milk supplementation is crucial for their progress. Due to the different characteristics of human breast milk, as well as ubiquitous environmental pollutants, such as microplastics, new methods are required for monitoring the quality and characteristics of human milk, which will lay a solid foundation for the further development and progress of human milk research.

Isolation of Human Milk Difucosyl Nona- and Decasaccharides by Ultrahigh-Temperature Preparative PGC-HPLC and Identification of Novel Difucosylated Heptaose and Octaose Backbones by Negative-Ion ESI-MSn

Despite their many important physiological functions, past work on the diverse sequences of human milk oligosaccharides (HMOs) has been focused mainly on the highly abundant HMOs with a relatively low degree of polymerization (DP) due to the lack of efficient methods for separation/purification and high-sensitivity sequencing of large-sized HMOs with DP ≥ 10. Here we established an ultrahigh-temperature preparative HPLC based on a porous graphitized carbon column at up to 145 °C to overcome the anomeric α/β splitting problem and developed further the negative-ion ESI-CID-MS/MS into multistage MSn using a combined product-ion scanning of singly charged molecular ion and doubly charged fragment ion of the branching Gal and adjacent GlcNAc residues. The separation and sequencing method allows efficient separation of a neutral fraction with DP ≥ 10 into 70 components, among which 17 isomeric difucosylated nona- and decasaccharides were further purified and sequenced. As a result, novel branched difucosyl heptaose and octaose backbones were unambiguously identified in addition to the conventional linear and branched octaose backbones. The novel structures of difucosylated DF-novo-heptaose, DF-novo-LNO I, and DF-novo-LNnO I were corroborated by NMR. The various fucose-containing Lewis epitopes identified on different backbones were confirmed by oligosaccharide microarray analysis.

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.

Protein Engineering of a Novel β-Galactosidase from Thermus scotoductus for Efficient Synthesis of Lacto-N-Neotetraose from Chitin Powder

A novel β-galactosidase (TsGal48) from Thermus scotoductus was cloned, and the enzyme was biochemically characterized. TsGal48 catalyzed the synthesis of lacto-N-neotetraose (LNnT) from lactose via the transglycosylation reaction with a maximal yield of 20%, which is the highest yield for the synthesis of LNnT so far. To further improve the yield of LNnT, TsGal48 was successfully engineered by directed evolution and site-saturation mutagenesis. A mutated β-galactosidase (mTsGal48) was selected and characterized. mTsGal48 produced LNnT with a yield of 27.7 g/L, which is 1.4-fold higher than that of TsGal48 (19.7 g/L). Then, a developed strategy for LNnT synthesis from chitin powder was provided in a 30 L bioreactor. The reaction process included chitin powder hydrolysis, lacto-N-triose II (LNT2) synthesis, and LNnT synthesis. The reaction time was reduced from 44 to 17 h in chitin powder hydrolysis and LNT2 synthesis. The content of LNnT was up to 25 g/L in the multienzyme system. The green and efficient route may be suitable for large-scale production of LNnT from chitin powder.

Life-threatening infections in human newborns: Reconciling age-specific vulnerability and interindividual variability

In humans, the interindividual variability of clinical outcome following exposure to a microorganism is immense, ranging from silent infection to life-threatening disease. Age-specific immune responses partially account for the high incidence of infection during the first 28 days of life and the related high mortality at population level. However, the occurrence of life-threatening disease in individual newborns remains unexplained. By contrast, inborn errors of immunity and their immune phenocopies are increasingly being discovered in children and adults with life-threatening viral, bacterial, mycobacterial and fungal infections. There is a need for convergence between the fields of neonatal immunology, with its in-depth population-wide characterization of newborn-specific immune responses, and clinical immunology, with its investigations of infections in patients at the cellular and molecular levels, to facilitate identification of the mechanisms of susceptibility to infection in individual newborns and the design of novel preventive and therapeutic strategies.

More than nutrition: Therapeutic potential and mechanism of human milk oligosaccharides against necrotizing enterocolitis

Human milk is the most valuable source of nutrition for infants. The structure and function of human milk oligosaccharides (HMOs), which are key components of human milk, have long been attracting particular research interest. Several recent studies have found HMOs to be efficacious in the prevention and treatment of necrotizing enterocolitis (NEC). Additionally, they could be developed in the future as non-invasive predictive markers for NEC. Based on previous findings and the well-defined functions of HMOs, we summarize potential protective mechanisms of HMOs against neonatal NEC, which include: modulating signal receptor function, promoting intestinal epithelial cell proliferation, reducing apoptosis, restoring intestinal blood perfusion, regulating microbial prosperity, and alleviating intestinal inflammation. HMOs supplementation has been demonstrated to be protective against NEC in both animal studies and clinical observations. This calls for mass production and use of HMOs in infant formula, necessitating more research into the safety of industrially produced HMOs and the appropriate dosage in infant formula.

Minimizing acetate formation from overflow metabolism in Escherichia coli: comparison of genetic engineering strategies to improve robustness toward sugar gradients in large-scale fermentation processes

Introduction: Escherichia coli, a well characterized workhorse in biotechnology, has been used to produce many recombinant proteins and metabolites, but have a major drawback in its tendency to revert to overflow metabolism. This phenomenon occurs when excess sugar triggers the production of mainly acetate under aerobic conditions, a detrimental by-product that reduces carbon efficiency, increases cell maintenance, and ultimately inhibits growth. Although this can be prevented by controlled feeding of the sugar carbon source to limit its availability, gradients in commercial-scale bioreactors can still induce it in otherwise carbon-limited cells. While the underlying mechanisms have been extensively studied, these have mostly used non-limited cultures. In contrast, industrial production typically employs carbon-limited processes, which results in a substantially different cell physiology. Objective: The objective of this study was to evaluate and compare the efficiency of different metabolic engineering strategies with the aim to reduce overflow metabolism and increase the robustness of an industrial 2'-O-fucosyllactose producing strain under industrially relevant conditions. Methods: Three distinct metabolic engineering strategies were compared: i) alterations to pathways leading to and from acetate, ii) increased flux towards the tricarboxylic acid (TCA) cycle, and iii) reduced glucose uptake rate. The engineered strains were evaluated for growth, acetate formation, and product yield under non-limiting batch conditions, carbon limited fed-batch conditions, and after a glucose pulse in fed-batch mode. Results and Discussion: The findings demonstrated that blockage of the major acetate production pathways by deletion of the pta and poxB genes or increased carbon flux into the TCA cycle by overexpression of the gltA and deletion of the iclR genes, were efficient ways to reduce acetate accumulation. Surprisingly, a reduced glucose uptake rate did not reduce acetate formation despite it having previously been shown as a very effective strategy. Interestingly, overexpression of gltA was the most efficient way to reduce acetate accumulation in non-limited cultures, whereas disruption of the poxB and pta genes was more effective for carbon-limited cultures exposed to a sudden glucose shock. Strains from both strategies showed increased tolerance towards a glucose pulse during carbon-limited growth indicating feasible ways to engineer industrial E. coli strains with enhanced robustness.

Shaping microbiome function with a human milk-oligosaccharide synbiotic

In a recent article, Button and colleagues demonstrate that human milk oligosaccharides create a nutrient niche that supports reversible colonization by Bifidobacterium infantis. Using this tunable system, they assessed the impact of B. infantis on microbiome recovery after antibiotic treatment. Overall, this work highlights synbiotics as a useful approach for developing live biotherapeutic products (LBPs).

The Role of Diet and Nutritional Interventions for the Infant Gut Microbiome

The infant gut microbiome plays a key role in the healthy development of the human organism and appears to be influenced by dietary practices through multiple pathways. First, maternal diet during pregnancy and infant nutrition significantly influence the infant gut microbiota. Moreover, breastfeeding fosters the proliferation of beneficial bacteria, while formula feeding increases microbial diversity. The timing of introducing solid foods also influences gut microbiota composition. In preterm infants the gut microbiota development is influenced by multiple factors, including the time since birth and the intake of breast milk, and interventions such as probiotics and prebiotics supplementation show promising results in reducing morbidity and mortality in this population. These findings underscore the need for future research to understand the long-term health impacts of these interventions and for further strategies to enrich the gut microbiome of formula-fed and preterm infants.

From Birth to Weaning: A Window of Opportunity for Microbiota

(1) Background: The first 1000 days of life constitute a critical window of opportunity for microbiota development. Nutrients play a crucial role in enriching and diversifying the microbiota, derived not only from solid food but also from maternal dietary patterns during gestation. (2) Methods: We conducted a comprehensive literature review using the PubMed database, covering eleven years (2013-2023). We included English-language reviews, original research papers, and meta-analyses, while excluding case reports and letters. (3) Results: Consensus in the literature emphasizes that our interaction with a multitude of microorganisms begins in the intrauterine environment and continues throughout our lives. The existing data suggest that early nutritional education programs, initiated during pregnancy and guiding infant diets during development, may influence the shaping of the gut microbiota, promoting long-term health. (4) Conclusions: Further research is necessary in the coming years to assess potential interventions and early nutritional models aimed at modulating the pediatric microbiota, especially in vulnerable populations such as premature newborns.

Composition of Microbiota in Transient and Mature Human Milk: Significant Changes in Large for Gestational Age Group

The composition of the human milk (HM) microbiota and, consequently, the microorganisms that are passed on to the infant through breastfeeding, can be influenced by various factors such as the mother's health and diet, gestational age, delivery mode, lactation stage, method of infant feeding, and geographical location. The aim of the Human Milk-Gest Study was to compare the microbiota of transient (postpartum 7-15 days) and mature HM (postpartum 45-90 days) of 44 mothers, and to investigate any potential changes associated with preterm birth, mode of delivery, and birth weight in relation to gestational age. The data were classified into five study groups: normal spontaneous delivery-term (NS-T) newborns, cesarean delivery-term (CS-T) newborns, preterm (PT) newborns (with a gestational age of less than 37 weeks), small for gestational age (SGA) newborns, and large for gestational age (LGA) newborns. An analysis of differential abundance was conducted using ANCOM-BC to compare the microbial genera between transient and mature HM samples as well as between other study groups. A significant difference was detected between HM samples at different sampling times and between the study groups (p < 0.01). In transient HM samples, Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group compared to the NS-T, CS-T, PT, and SGA groups. In mature HM samples, Burkholderiaceae_uc, Ralstonia, Pelomonas, and Klebsiella were significantly dominant in the LGA group compared to the NS-T, CS-T, and PT groups, while Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group compared to the SGA group. Differences were also detected between the transient and mature HM samples in the CS-T, PT, SGA, and LGA groups, but no differences occurred in the NS-T groups. In conclusion, we showed that Ralstonia, Burkholderiaceae_uc, and Pelomonas were significantly dominant in the LGA group in transient HM and continued in mature HM. The body mass index (BMI) of the mothers in the LGA group was not >30 at conception, however, the maternal BMI at birth and maternal weight gain during pregnancy were higher than in the other groups. The nutritional composition of HM is specifically designed to meet infant nutritional requirements during early life. Evaluating the effects of HM microbiota on infant microbiota composition and short- and long-term health effects in larger studies would be useful.

Insights into the Structure, Metabolism, Biological Functions and Molecular Mechanisms of Sialic Acid: A Review

Sialic acid (SA) is a kind of functional monosaccharide which exists widely in edible bird's nest (EBN), milk, meat, mucous membrane surface, etc. SA is an important functional component in promoting brain development, anti-oxidation, anti-inflammation, anti-virus, anti-tumor and immune regulation. The intestinal mucosa covers the microbial community that has a significant impact on health. In the gut, SA can also regulate gut microbiota and metabolites, participating in different biological functions. The structure, source and physiological functions of SA were reviewed in this paper. The biological functions of SA through regulating key signaling pathways and target genes were discussed. In summary, SA can modulate gut microbiota and metabolites, which affect gene expressions and exert its biological activities. It is helpful to provide scientific reference for the further investigation of SA in the functional foods.

An Overview of the Influence of Breastfeeding on the Development of Inflammatory Bowel Disease

The first 1000 days of life is a critical period that contributes significantly to the programming of an individual's future health. Among the many changes that occur during this period early in life, there is growing evidence that the establishment of healthy gut microbiota plays an important role in the prevention of both short- and long-term health problems. Numerous publications suggest that the quality of the gut microbiota colonisation depends on several dietary factors, including breastfeeding. In this respect, a relationship between breastfeeding and the risk of inflammatory bowel disease (IBD) has been suggested. IBDs are chronic intestinal diseases, and perinatal factors may be partly responsible for their onset. We review the existence of links between breastfeeding and IBD based on experimental and clinical studies. Overall, despite encouraging experimental data in rodents, the association between breastfeeding and the development of IBD remains controversial in humans, partly due to the considerable heterogeneity between clinical studies. The duration of exclusive breastfeeding is probably decisive for its lasting effect on IBD. Thus, specific improvements in our knowledge could support dietary interventions targeting the gut microbiome, such as the early use of prebiotics, probiotics or postbiotics, in order to prevent the disease.

Alterations of milk oligosaccharides in mothers with gestational diabetes mellitus impede colonization of beneficial bacteria and development of RORγt+ Treg cell-mediated immune tolerance in neonates

Gestational diabetes mellitus (GDM) is an increasing public health concern that significantly increases the risk of early childhood allergic diseases. Altered maternal milk glycobiome may strongly affect gut microbiota and enteric-specific Treg cell-mediated development of immune tolerance in GDM infants. In this study, we found that, compared with healthy Chinese mothers, mothers with GDM had significantly lower levels of total and specific human milk oligosaccharides (HMOs) in their colostrum that subsequently increased with extension of lactation. This alteration in HMO profiles significantly delayed colonization of Lactobacillus and Bifidobacterium spp. in their breast-fed infants, resulting in a distinct gut microbial structure and metabolome. Further experiments in GDM mouse models indicated that decreased contents of milk oligosaccharides, mainly 3'-sialyllactose (3'-SL), in GDM maternal mice reduced colonization of bacteria, such as L. reuteri and L. johnsonii, in the neonatal gut, which impeded development of RORγt+ regulatory T (Treg) cell-mediated immune tolerance. Treatment of GDM neonates with 3'-SL, Lactobacillus reuteri (L. reuteri) and L. johnsonii promoted the proliferation of enteric Treg cells and expression of transcription factor RORγt, which may have contributed to compromising ovalbumin (OVA)-induced allergic responses. In vitro experiments showed that 3'-SL, metabolites of L. johnsonii, and lysates of L. reuteri stimulated differentiation of mouse RORγt+ Treg cells through multiple regulatory effects on Toll-like receptor, MAPK, p53, and NOD-like receptor signaling pathways. This study provides new ideas for the development of gut microbiota and immune tolerance in GDM newborns.

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.

Clinical Studies on the Supplementation of Manufactured Human Milk Oligosaccharides: A Systematic Review

Human milk oligosaccharides (HMOs) are a major component of human milk. They are associated with multiple health benefits and are manufactured on a large scale for their addition to different food products. In this systematic review, we evaluate the health outcomes of published clinical trials involving the supplementation of manufactured HMOs. We screened the PubMed database and Cochrane Library, identifying 26 relevant clinical trials and five publications describing follow-up studies. The clinical trials varied in study populations, including healthy term infants, infants with medical indications, children, and adults. They tested eight different HMO structures individually or as blends in varying doses. All trials included safety and tolerance assessments, and some also assessed growth, stool characteristics, infections, gut microbiome composition, microbial metabolites, and biomarkers. The studies consistently found that HMO supplementation was safe and well tolerated. Infant studies reported a shift in outcomes towards those observed in breastfed infants, including stool characteristics, gut microbiome composition, and intestinal immune markers. Beneficial gut health and immune system effects have also been observed in other populations following HMO supplementation. Further clinical trials are needed to substantiate the effects of HMO supplementation on human health and to understand their structure and dose dependency.