Newborn Gut Research Articles

Characterization of newborn gut microbiota according to the pre-gestational maternal nutritional status and delivery mode.

The aim of this study is to characterize the composition of the newborn gut microbiota based on the maternal pre-pregnancy nutritional status and the delivery mode. A biological sample was collected from the anal mucosa of the newborns between 24 and 48h after delivery, as it was not possible to collect a meconium sample at that time. A general data collection questionnaire was administered. The microbiome of the samples was analyzed by next-generation sequencing of the hypervariable regions v3-v4 of the 16S gene. Alpha diversity analyses were performed using the Observed Richness and Shannon diversity index metrics and Beta diversity analyses were conducted using Nonmetric multidimensional scaling with Weighted Unifrac, Differential abundance analysis was performed using a Negative Binomial Wald Test with maximum likelihood estimation for coefficients of Generalized Linear Models. Newborns of obese mothers exhibited lower alpha diversity compared to newborns of mothers with adequate BMI (body mass index). We observed variation in the composition of the microbial community in newborn stool samples, both from mothers with overweight/obesity and those with adequate pre-pregnancy BMI. We observed a visible correlation between the mode of delivery and the newborn's microbiota. We found variation in the overall composition of the microbial community in the stools of newborns, regardless of the delivery mode. The results of our study demonstrate differences in the microbiota of neonates born via cesarean section compared to those born vaginally as well as differences in newborns of mothers with overweight/obesity compared to those with an adequate pre-pregnancy BMI.

Rotavirus-Specific Maternal Serum Antibodies and Vaccine Responses to RV3-BB Rotavirus Vaccine Administered in a Neonatal or Infant Schedule in Malawi.

High titres of rotavirus-specific maternal antibodies may contribute to lower rotavirus vaccine efficacy in low- and middle-income countries (LMICs). RV3-BB vaccine (G3P[6]) is based on a neonatal rotavirus strain that replicates well in the newborn gut in the presence of breast milk. This study investigated the association between maternal serum antibodies and vaccine response in infants administered the RV3-BB vaccine. Serum was collected antenatally from mothers of 561 infants enrolled in the RV3-BB Phase II study conducted in Blantyre, Malawi, and analysed for rotavirus-specific serum IgA and IgG antibodies using enzyme-linked immunosorbent assay. Infant vaccine take was defined as cumulative IgA seroconversion (≥3 fold increase) and/or stool vaccine shedding. Maternal IgA or IgG antibody titres did not have a negative impact on vaccine-like stool shedding at any timepoint. Maternal IgG (but not IgA) titres were associated with reduced take post dose 1 (p < 0.005) and 3 (p < 0.05) in the neonatal vaccine schedule group but not at study completion (week 18). In LMICs where high maternal antibodies are associated with low rotavirus vaccine efficacy, RV3-BB in a neonatal or infant vaccine schedule has the potential to provide protection against severe rotavirus disease.

Meconium microbiota in naturally delivered canine puppies

BackgroundMicrobial colonization during early life has a pivotal impact on the host health, shaping immune and metabolic functions, but little is known about timing and features of this process in dogs. The objectives of this study were to characterize the first step of intestinal microbiota development in naturally delivered canine puppies and to investigate its relationship with the maternal bacterial flora, using traditional culture and molecular analyses. Sixty puppies of two breeds, Appenzeller Cattle Dog (n = 3 dams) and Lagotto Romagnolo (n = 6), housed in the same breeding kennel, were included in the study. Swabs were collected in duplicate (for culture and for molecular analysis) from the dams’ vagina and rectum at the end of parturition, from puppies’ rectum, before maternal care, and from the environment (floor of the nursery and parturition box).Results93.3% meconium samples showed bacterial growth, limited to a few colonies in 57.0% of cases. High growth was detected for Enterococcus faecalis, which was the most frequently isolated bacterium. The genus Enterococcus was one of the most represented in the dams’ rectum and vagina (88.9% and 55.6%, respectively). The genera Staphylococcus, Enterococcus, Escherichia and Proteus were also often isolated in meconium but were usually present in maternal samples as well, together with ubiquitous bacteria (Acinetobacter, Psychrobacter). In the environmental samples, just a few bacterial species were found, all with low microbial load. Additionally, bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were identified in meconium through molecular analysis, confirming the culture results and the early colonization of the newborn gut. Maternal, meconium and environmental samples had similar alpha diversity, while beta-diversity showed differences among families (i.e. a dam and her litter), and association indexes revealed a significant correlation between family members and between sample origin, suggesting a strong contribution of the maternal flora to the initial seeding of the canine neonatal gut and a strong individual dam imprint.ConclusionThis study showed that the meconium of vaginally delivered puppies has its own microbiota immediately after birth, and that it is shaped by the dam, which gives a specific imprint to her litter.

Cord Obstruction and Delayed Cord Clamping Do Not Affect Gut Function in Neonatal Piglets

Introduction: Birth-related obstruction of umbilical blood flow may induce hypoxic insults that affect postnatal organ adaptation. Using newborn cesarean-delivered pigs, we hypothesized that cord obstruction during delivery negatively affects physiological transition and gut maturation. Further, we investigated if delayed cord clamping (DCC) improves gut outcomes, including sensitivity to formula-induced necrotizing enterocolitis (NEC)-like lesions. Methods: In experiment 1, preterm (n = 24) and near-term (n = 29) piglets were subjected to umbilical cord obstruction (UCO, 5–7 min in utero), with corresponding pigs delivered without obstruction (CON, n = 17–22). Experiment 2 assessed preterm pigs subjected to delayed cord clamping (n = 30, 60 s) or immediate cord transection with umbilical cord milking (UCM, n = 34). Postnatal vital parameters were recorded, together with a series of gut parameters after 3 days of formula feeding. Results: UCO induced respiratory-metabolic acidosis in near-term pigs at birth (pH 7.16 vs. 7.32, pCO2 12.5 vs. 9.2 kPa, lactate 5.2 vs. 2.5 mmol/L, p < 0.05). In preterm pigs, UCO increased failure of resuscitation and mortality shortly after birth (88 vs. 47%, p < 0.05). UCO did not affect gut permeability, transit time, macromolecule absorption, six digestive enzymes, or sensitivity to NEC-like lesions. In experiment 2, DCC improved neonatal hemodynamics (pH 7.28 vs. 7.20, pCO2 8.9 vs. 9.9 at 2 h, p < 0.05), with no effects on gut parameters. Conclusion: UCO and DCC affect neonatal transition and hemodynamics, but not neonatal gut adaptation or sensitivity to NEC-like lesions. Our findings suggest that the immature newborn gut is highly resilient to transient birth-related changes in cord blood flow.

Post Natal Microbial and Metabolite Transmission: The Path from Mother to Infant.

The entero-mammary pathway is a specialized route that selectively translocates bacteria to the newborn's gut, playing a crucial role in neonatal development. Previous studies report shared bacterial and archaeal taxa between human milk and neonatal intestine. However, the functional implications for neonatal development are not fully understood due to limited evidence. This study aimed to identify and characterize the microbiota and metabolome of human milk, mother, and infant stool samples using high-throughput DNA sequencing and FT-ICR MS methodology at delivery and 4 months post-partum. Twenty-one mothers and twenty-five infants were included in this study. Our results on bacterial composition suggest vertical transmission of bacteria through breastfeeding, with major changes occurring during the first 4 months of life. Metabolite chemical characterization sheds light on the growing complexity of the metabolites. Further data integration and network analysis disclosed the interactions between different bacteria and metabolites in the biological system as well as possible unknown pathways. Our findings suggest a shared bacteriome in breastfed mother-neonate pairs, influenced by maternal lifestyle and delivery conditions, serving as probiotic agents in infants for their healthy development. Also, the presence of food biomarkers in infants suggests their origin from breast milk, implying selective vertical transmission of these features.

Delayed colonization of Bifidobacterium spp. and low prevalence of B. infantis among infants of Asian ancestry born in Singapore: insights from the GUSTO cohort study.

The loss of ancestral microbes, or the "disappearing microbiota hypothesis" has been proposed to play a critical role in the rise of inflammatory and immune diseases in developed nations. The effect of this loss is most consequential during early-life, as initial colonizers of the newborn gut contribute significantly to the development of the immune system. In this longitudinal study (day 3, week 3, and month 3 post-birth) of infants of Asian ancestry born in Singapore, we studied how generational immigration status and common perinatal factors affect bifidobacteria and Bifidobacterium longum subsp. infantis (B. infantis) colonization. Cohort registry identifier: NCT01174875. Our findings show that first-generation migratory status, perinatal antibiotics usage, and cesarean section birth, significantly influenced the abundance and acquisition of bifidobacteria in the infant gut. Most importantly, 95.6% of the infants surveyed in this study had undetectable B. infantis, an early and beneficial colonizer of infant gut due to its ability to metabolize the wide variety of human milk oligosaccharides present in breastmilk and its ability to shape the development of a healthy immune system. A comparative analysis of B. infantis in 12 countries by their GDP per capita showed a remarkably low prevalence of this microbe in advanced economies, especially Singapore. This study provides new insights into infant gut microbiota colonization, showing the impact of generational immigration on early-life gut microbiota acquisition. It also warrants the need to closely monitor the declining prevalence of beneficial microbes such as B. infantis in developed nations and its potential link to increasing autoimmune and allergic diseases.

Inoculation of Newborn Lambs with Ruminal Solids Derived from Adult Goats Reprograms the Development of Gut Microbiota and Serum Metabolome and Favors Growth Performance.

Microbial transplantation in early life was a strategy to optimize the health and performance of livestock animals. This study aimed to investigate the effect of active ruminal solids microorganism supplementation on newborn lamb gut microbiota and serum metabolism. Twenty-four Youzhou dark newborn lambs were randomly divided into three groups: (1) newborn lambs fed with sterilized goat milk inoculated with sterilized normal saline (CON), supernatant from ruminal solids (SRS), or autoclaved supernatant from ruminal solids (ASRS). Results showed that SRS increased gut bacterial richness and community, downregulating the Firmicutes/Bacteroidetes ratio, and increased the abundance of some probiotics (Bacteroidetes, Spirochaetota, and Fibrobacterota), while reducing the abundance of Fusobacteriota, compared to the CON group. SRS also improved the plasma metabolic function, such as arachidonic acid metabolism, primary bile acid biosynthesis, and tryptophan metabolism and then actively promoted the levels of ALP and HLD. Our study indicated that inoculation with active ruminal solids significantly affected the intestinal microbial communities and metabolic characteristics, and these changes can improve the growing health of the newborn lamb. These findings provided an experimental and theoretical basis for the application of ruminal solid-attached microorganisms in the nutritional management of lambs reared for human consumption.

Temporal colonization and metabolic regulation of the gut microbiome in neonatal oxen at single nucleotide resolution.

The colonization of microbes in the gut is key to establishing a healthy host-microbiome symbiosis for newborns. We longitudinally profiled the gut microbiome in a model consisting of 36 neonatal oxen from birth up to 2months postpartum and carried out microbial transplantation to reshape their gut microbiome. Genomic reconstruction of deeply sequenced fecal samples resulted in a total of 3931 metagenomic-assembled genomes from 472 representative species, of which 184 were identified as new species when compared with existing databases of oxen. Single nucleotide level metagenomic profiling shows a rapid influx of microbes after birth, followed by dynamic shifts during the first few weeks of life. Microbial transplantation was found to reshape the genetic makeup of 33 metagenomic-assembled genomes (FDR < 0.05), mainly from Prevotella and Bacteroides species. We further linked over 20 million microbial single nucleotide variations to 736 plasma metabolites, which enabled us to characterize 24 study-wide significant associations (P < 4.4 × 10-9) that identify the potential microbial genetic regulation of host immune and neuro-related metabolites, including glutathione and L-dopa. Our integration analyses further revealed that microbial genetic variations may influence the health status and growth performance by modulating metabolites via structural regulation of their encoded proteins. For instance, we found that the albumin levels and total antioxidant capacity were correlated with L-dopa, which was determined by single nucleotide variations via structural regulations of metabolic enzymes. The current results indicate that temporal colonization and transplantation-driven strain replacement are crucial for newborn gut development, offering insights for enhancing newborn health and growth.

First year of life: the Golden Age of gut microbiota

During the first year of life, development and balance of newborn gut microbiota are strongly influenced by external factors such as delivery mode, breastfeeding, duration of pregnancy, mother diet and lifestyle, siblings and pets, environment, and antibiotics administration. Gut microbiota colonization starts with facultative anaerobes and continues with the establishment of anaerobic genera of which Bifidobacteria are the gold standard of a healthy gut neonatal microbiota. Scientific literature traditionally describes the fetus as sterile in the womb and identifies the membranes rupture as the beginning of microbial colonization. Vaginal delivery is an important source for the onset of infant colonization which will then continue with the transfer of a new selection of intestinal bacteria with breastfeeding. During cesarean delivery a direct contact of the mouth of newborn with the vaginal and intestinal microbiota is absent, and environmental bacteria play an important role for infants intestinal colonization. Nature has ensured that newborns receive other specific maternal bacteria, through a subsequent method of transfer: breastfeeding. We present a brief and comprehensive state-of-the-art in order to encourage natural childbirth and breastfeeding whenever possible and discuss innovative directions for develop new ad hoc personalized treatments in order to restore physiological microbiota.

The role of anti-E. coli antibody from maternal colostrum on the colonization of newborn dairy calves gut with Escherichia coli and the development of clinical diarrhea

Escherichia coli (E. coli) is an early organism in the colonization of mucosal tissue and has an influence on the development of mucosal and systemic inflammatory responses. To understand the impact of transfer of Immunoglobulin G (IgG), E. coli-specific antibody and general immune factors to the calf on the gut microbiota, an observational study that followed the temporal colonization of the intestine with E. coli as correlated with the total quantity of IgG and the antibody recognizing E. coli, was conducted in newborn Holstein calves. The calves were subjected to the “gold standard” of colostrum management, including dam vaccination prior to delivery to prime colostrum. Twenty Holstein dams, producing an adequate quantity of good-quality colostrum following uncomplicated deliveries of healthy female offspring, were utilized in this study. Each calf was monitored and scored daily for diarrhea. Blood and fecal samples were collected from calves on day (D) D1 (before colostrum intake), then D3, D7, D14 and D28 after colostrum feeding. E. coli isolated from fecal samples of the calves were assessed for virulence genes and the quantity per gram of feces using conventional Polymerase chain reaction and Real-time polymerase chain reaction quantitative, respectively. The total quantity of plasma IgG and the titer of E. coli-binding antibody were measured by enzyme-linked immunosorbent assay. The peak in diarrhea in the calves was observed on D12. No IgG or E. coli-binding antibody were detected prior to colostrum intake (D1). Both total IgG and binding antibody sharply increased by D3. Total and binding IgG declined with calf age. The total number of bacteria (16S rRNA) in feces was similar between D1 and D14. The number of total bacteria increased over the period from D14 to D28. The number of E. coli was minimal on D1. The number of E. coli increased during the period D3-D7. A decrease in the number of E. coli per gram of feces declines between D14and D28. The stable toxin gene was frequently identified in the E. coli isolated from the calves. Further, E. coli K99 was not identified in this study. While the gut was colonized by E. coli early in life corresponding to the peak level of IgG and specific antibody, a decreasing number of E. coli were observed as the passive immunity waned. This suggests that the function of the passive antibody may be to control colonization and seed innate immune function that then stabilizes the level of E. coli in the digestive tract of calves.

Effect of Breastmilk Microbiota and Sialylated Oligosaccharides on the Colonization of Infant Gut Microbial Community and Fecal Metabolome.

The complex microbiota and sialylated oligosaccharides in breastmilk are important bioactive components that affect the gut microbiota. However, the effect of breastmilk microbiota and sialylated oligosaccharides on the gut microbiota during the neonatal period has been largely overlooked. Here, 16S rRNA gene sequencing and metabolomics analysis were applied to the breastmilk and feces of 69 newborns to clarify the link between breastmilk components and the newborn gut. Results showed that Staphylococcus, Enterococcus, and Bacteroides were commonly shared and positively correlated between breastmilk and the neonatal intestine and they were the main bacteria of breastmilk that interacted with the newborn fecal metabolome. Breastmilk Staphylococcus mainly interacted with amino acids, whereas Bacteroides was involved in the tryptophan, nucleotide, and vitamin metabolism. Breastmilk sialylated oligosaccharides were related to Bacteroides and amino acids of the newborn fecal metabolites. Moreover, Bacteroides was related to the interaction between breastmilk 3'-sialyllactose and newborn fecal metabolites in the mediation effect models. Finally, we pointed out that breastmilk Bacteroides was important in the milk-gut interaction, and it was negatively associated with waist circumference in infants aged 1 year. Our study provides a scientific basis for understanding the role of breastmilk in the development of newborn gut microbiota and metabolome.

The effect of pre-pregnancy obesity on gut and meconium microbiome and relationship with fetal growth

Objective To investigate the effect of pre-pregnancy obesity on maternal and newborn microbiomes and fetal growth. Methods Individuals who gained body weight in accordance with the recommendations during pregnancy and normal gestastional age are included in the study and were separated into two groups, normal (n = 20) and obese (n = 20), based on their body mass index (BMI) value of pre-pregnancy. Maternal stool samples collected during the first trimester of pregnancy and meconium samples collected at birth were evaluated using 16S rRNA gene-based microbiome analysis. Results The stool samples of mothers who were obese before pregnancy harbored a higher (59.9 versus 52.3%) relative abundance of Firmicutes and a lower (7.1 versus 4.1%) relative abundance of Proteobacteria than the stool samples of mothers with normal body weight pre-pregnancy. In contrast, in the meconium samples of mothers who were obese pre-pregnancy, compared to those of mothers who had a normal body weight pre-pregnancy, the phylum Firmicutes was less (56.0 versus 69.0%) abundant and Proteobacteria (9.0 versus 8.5%) was more abundant. There was a negative correlation between pre-pregnancy BMI, birth weight, weight/height ratio and alpha diversity indices (Shannon and Chao1). Conclusions Pre-pregnancy obesity can affect pregnant and newborn gut microbiota, which might related to fetal growth of the newborn.

Metabolic model of necrotizing enterocolitis in the premature newborn gut resulting from enteric dysbiosis

Necrotizing enterocolitis (NEC) is a leading cause of premature newborn morbidity and mortality. The clinical features of NEC consistently include prematurity, gut dysbiosis and enteral inflammation, yet the pathogenesis remains obscure. Herein we combine metagenomics and targeted metabolomics, with functional in vivo and in vitro assessment, to define a novel molecular mechanism of NEC. One thousand six hundred and forty seven publicly available metagenomics datasets were analyzed (NEC = 245; healthy = 1,402) using artificial intelligence methodologies. Targeted metabolomic profiling was used to quantify the concentration of specified fecal metabolites at NEC onset (n = 8), during recovery (n = 6), and in age matched controls (n = 10). Toxicity assays of discovered metabolites were performed in vivo in mice and in vitro using human intestinal epithelial cells. Metagenomic and targeted metabolomic analyses revealed significant differences in pyruvate fermentation pathways and associated intermediates. Notably, the short chain fatty acid formate was elevated in the stool of NEC patients at disease onset (P = 0.005) dissipated during recovery (P = 0.02) and positively correlated with degree of intestinal injury (r2 = 0.86). In vitro, formate caused enterocyte cytotoxicity in human cells through necroptosis (P < 0.01). In vivo, luminal formate caused significant dose and development dependent NEC-like injury in newborn mice. Enterobacter cloacae and Klebsiella pneumoniae were the most discriminatory taxa related to NEC dysbiosis and increased formate production. Together, these data suggest a novel biochemical mechanism of NEC through the microbial production of formate. Clinical efforts to prevent NEC should focus on reducing the functional consequences of newborn gut dysbiosis associated metabolic pathways.

The role of anti-E.coli Antibody from Maternal Colostrum on the Colonization Of Newborn Dairy Calves Gut with Escherichia Coli and the Development of Clinical Diarrhea

The role of anti-E.coli Antibody from Maternal Colostrum on the Colonization Of Newborn Dairy Calves Gut with Escherichia Coli and the Development of Clinical Diarrhea

The role of anti-E.coli Antibody from Maternal Colostrum on the Colonization Of Newborn Dairy Calves Gut with Escherichia Coli and the Development of Clinical Diarrhea

The role of anti-E.coli Antibody from Maternal Colostrum on the Colonization Of Newborn Dairy Calves Gut with Escherichia Coli and the Development of Clinical Diarrhea

Breast milk microbiota (concept, sources, role of bacteria for a child and mother)

Scientific discoveries of recent years demonstrate a crucial role of the human microbiome in human health. The establishment of a healthy, functional gut microbiota of the newborn requires physiological conditions, one of which is breastfeeding. The role of breast milk as a “direct supplier” of live microbes for the establishment of the newborn gut microbiota became known only at the beginning of the new millennium, previously it was believed that the breast milk was sterile. Today, the breast milk microbiota can be defined as multi-species assemblage, in which microbes interact with each, representing a complex organized ecosystem, among which the genera Streptococcus and Staphylococcus are dominant. Lactobacillus, Pseudomonas, Bifidobacterium, Corynebacterium, Enterococcus, Acinetobacter, Rothia, Cutibacterium, Veillonella and Bacteroides are also often referred to the common bacterial genera. The article presents two theories of the origin of bacteria in the breast milk (endogenous and exogenous bacterial translocation pathways) and explains why both of them are true. The role of bacteria in the breast milk of healthy women, in the global sense, is viewed in the context of the establishment of the infant gut microbiota. The article lists the main producers of antibacterial peptides (bacteriocins) in the breast milk and considers the effective immunological protection using the example of the population of bifidobacteria and bacteroids prevailing in the breastfed infant gut. However, the breast milk microbiota is also important for women’s health. We tried to explain why infectious lactational mastitis is now considered to be the result of dysbiosis in the mammary ecosystem, which leads to the development of an inflammatory process, and why Streptococcus thermophilus (TCI633) shows promise in the fight against human ageing.

Lactation-dependent vertical transmission of natural probiotics from the mother to the infant gut through breast milk.

The transmission of certain bacteria from the mother's gut to the infant's gut via breast milk (BM) is critical for the offspring's immune system development. Dysbiosis of the BM microbiota can be caused by a variety of reasons, which can be influenced by probiotics delivered via the enteromammary route. The goal of this study was to investigate the bacteria that can be transmitted from the mother to the infant's intestine during various lactation periods in 19 mother-child dyads. Bacterial transmission is most common during the colostrum phase when bacteria with certain amplicon sequence variants (ASVs) enter the newborn intestine and inhabit it permanently. We have established that anaerobic gut-associated bacteria, such as Faecalibacterium, Blautia and Lachnoclostridium, transfer from the mother to the infant's gut with lactation dependence using the idea of weighted transfer ratios. Streptococcus salivarius, Bifidobacterium longum, and Lactobacillus gasseri are transferred from the maternal gut to the BM, as well as from the BM to the newborn gut, depending on different ASVs. These findings suggest that isolation of key microorganisms from breast milk could be utilized to modify the microbiota of BM or newborns by giving the mother a probiotic or adding it to artificial milk to promote neonatal health.

Cross-talk between the infant/maternal gut microbiota and the endocrine system: a promising topic of research.

The infant gut microbiota is the set of microorganisms colonizing the baby's intestine. This complex ecosystem appears to be related to various physiological conditions of the host and it has also been shown to act as one of the most crucial determinants of infant's health. Furthermore, the mother's endocrine system, through its hormones, can have an effect on the composition of the newborn's gut microbiota. In this perspective, we summarize the recent state of the art on the intricate relationships involving the intestinal microbiota and the endocrine system of mother/baby to underline the need to study the molecular mechanisms that appear to be involved.

Vaginal microbiome dysbiosis in preterm birth.

All the environmentally exposed surfaces of the human body harbor ecologically distinct microbial communities with a mutualistic beneficial relationship. Depending on the body sites, microbes may provide metabolic functions, protection against pathogens, and signaling molecules to modulate host physiology and reduce disease susceptibility. Our recent understanding of the vaginal microbiome based on culture-independent 16S rRNA gene sequencing indicates that Lactobacillus-dominated microbial communities of healthy women play an important role in decreasing susceptibility to several urogenital diseases, including bacterial, fungal and viral infections. The findings of shotgun sequencing of the vaginal microbiome suggest that microbial-derived lactic acid, bacteriostatic, bactericidal molecules, and lower vaginal pH mediate such protections and regulations. Bacterial species, the dominant component of the vaginal microbiome, also play a key role in determining the gestation period and birth outcomes of reproductive-age women. The presence of Lactobacillus crispatus species in the vaginal milieu reduces the risk of preterm delivery in women of Asian ancestry. A deeper knowledge of the vaginal microbiota's role in the succession and development of newborn gut bacteria would also be beneficial. The microbiome of the mother changes throughout pregnancy and is linked to the microbiome of the newborn. This chapter highlights updated information and new opportunities for human microbiome research, focusing on the assessment of the risk of preterm birth.

Effect of supplementation with select human milk oligosaccharides on artificially reared newborn rats.

Early life nutrition fundamentally influences neonatal development and health. Human milk oligosaccharides (HMO) are key components of breast milk but not standard infant formula that support the establishment of the newborn gut microbiota. Using an artificial rearing system, our objective was to test the effect of two HMO on the whole body and organ growth, adiposity, glucose tolerance and faecal microbiota in young rat pups. From postnatal days 4 to 21, Sprague-Dawley rats were randomised to receive one of: (1) CTR (rat milk substitute); (2) 2'FL (CTR + 1·2 g/l 2'-fucosyllactose); (3) 3'SL (CTR + 1·2 g/l 3'-sialyllactose) and (4) 2'FL + 3'SL (CTR + 0·6 g/l 2'-FL + 0·6 g/l 3'-SL). Body weight (BW), bowel movements and food intake were monitored daily, faecal samples collected each week and oral glucose tolerance, body composition and organ weight measured at weaning. No significant differences were observed between groups in growth performance, body composition, organ weight and abundance of dominant faecal microbes. A decreased relative abundance of genus Proteus in week 1 faecal samples and Terrisporobacter in week 3 faecal samples (P < 0·05) was suggestive of a potential pathogen inhibitory effect of 3'SL. Longitudinal changes in the faecal microbiota of artificially reared suckling rats were primarily governed by age (P = 0·001) and not affected by the presence of 2'-FL and/or 3'-SL in rat milk substitutes (P = 0·479). Considering the known protective effects of HMO, further investigation of supplementation with these and other HMO in models of premature birth, extremely low BW or malnutrition may show more pronounced outcomes.