Neonatal Microbiota Research Articles

Gestational diabetes exacerbates intrauterine microbial exposure induced intestinal microbiota change in offspring contributing to increased immune response.

maternal health during pregnancy can affect the intestinal microbial community of offspring, but currently the impact of intrauterine environmental changes resulting from gestational diabetes mellitus (GDM) on the microbiota of offspring as well as its interaction with the immune system remains unclear. to explore the impact of intrauterine microbial exposure during pregnancy of gestational diabetes mellitus on the development of neonate's intestinal microbiota and activation of immune responses. Levels of lipopolysaccharides in cord blood from GDM and expression of microbial recognition-related proteins in the placenta were measured. To evaluate embryonic intestinal colonization, pregnant mice with GDM were administered with labeled Escherichia coli or Lactobacillus. The intestinal colonization of pups was analyzed through 16S rRNA gene sequencing and labeled microbial culture. Additionally, memory T lymphocyte and dendritic cell co-culture experiments were conducted to elucidate the immune memory of intestinal microbes during the embryonic stages. Gestational diabetes mellitus led to elevated umbilical cord blood LPS level and increased GFP labeled Escherichia coli in the offspring's intestine after gestational microbial exposure. The mouse model of GDM exhibited increased immune markers including TLR4, TLR5, IL-22 and IL-23 in the placenta and a recall response from memory T cells in offspring's intestines, with similar observations found in human experiments. Furthermore, reduced intestinal microbiome diversity and an increased ratio of Firmicutes/Bacteroidetes was found in GDM progeny, with the stability of bacterial colonization been interfered. Our investigation has revealed a noteworthy correlation between gestational diabetes and intrauterine microbial exposure, as well as alterations in the neonatal microbiota and activation of immune responses. These findings highlight the gestational diabetes's role on offspring's gut microbiota and immune system interactions with early-life pathogen exposure.

Dysbiosis of the initial stool microbiota increases the risk of developing necrotizing enterocolitis or feeding intolerance in newborns

Several perinatal factors influence the intestinal microbiome of newborns during the first days of life, whether during delivery or even in utero. These factors may increase the risk of developing necrotizing enterocolitis (NEC) by causing dysbiosis linked to a NEC-associated microbiota, which may also be associated with other gastrointestinal problems. The objective of our study was to evaluate the potential risks associated with microbial shifts in newborns with gastrointestinal symptoms and identify the intestinal microbiota of neonates at risk for NEC.During the study period, 310 preterm and term newborns’ first passed meconium occurring within 72 h of birth were collected, and the microbiome was analyzed. We identified the risk factors in the NEC/FI group. Regarding microbiota, we compared the bacterial abundance between the NEC/FI group at the phylum and genus levels and explored the differences in the microbial composition of the 1st stool samples. A total of 14.8% (n = 46) of the infants were diagnosed with NEC or FI. In univariate analysis, the mean gestational age and birth weight were significantly lower in the NEC/FI group (p < 0.001). Prolonged rupture of membranes (PROM) > 18 h, chorioamnionitis, and histology were significantly higher in the NEC/FI group (p < 0.001). Multivariate analysis showed that gestational age (GA), prolonged membrane rupture (> 18 h), and early onset sepsis were consistently associated with an increased risk of NEC/FI. Infants diagnosed with NEC/FI exhibited a significantly lower abundance of Actinobacteria at the phylum level than the control group (p < 0.001). At the genus level, a significantly lower abundance of Streptococcus and Bifidobacterium which belong to the Actinobacteria phylum, was observed in the NEC/FI group (p < 0.001). Furthermore, the NEC/FI had significantly lower alpha diversities (Shannon Index,3.39 vs. 3.12; P = 0.044, respectively). Our study revealed that newborns with lower diversity and dysbiosis in their initial gut microbiota had an increased risk of developing NEC, with microbiota differences appearing to be associated with NEC/FI. Dysbiosis could potentially serve as a predictive marker for NEC- or GI-related symptoms.

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.

Gram-Negative Colonization and Bacterial Translocation Drive Neonatal Sepsis in the Indian Setting.

The gut microbiota, comprising billions of microorganisms, plays a pivotal role in health and disease. This study aims to investigate the effect of sepsis on gut microbiome of neonates admitted to the Neonatal Intensive Care Unit. A prospective cohort study was carried out in the NICU of tertiary care hospital in Karnataka, India, from January 2021 to September 2023. Preterm neonates with birth weight < 1500g and gestational age < 37 weeks were recruited, excluding those with congenital gastrointestinal anomalies, necrotizing enterocolitis, or blood culture-negative infections. The study population was divided into three groups: healthy neonates (Group A), neonates with drug-sensitive GNB sepsis (Group B), and neonates with pan drug-resistant GNB sepsis (Group C). Stool samples were collected aseptically, snapped in liquid nitrogen, and stored at -80⁰C for extraction of DNA and microbiome analysis. The gut microbiota of healthy neonates (Group A) was dominated by Proteobacteria (24.04%), Actinobacteria (27.13%), Firmicutes (12.74%), and Bacteroidetes (3%). Predominant genera included Bifidobacterium (55.17%), Enterobacter (12.55%), Enterococcus (50.69%), Streptococcus (7.92%), and Bacteroides (3.58%).Groups B and C, the microbiota exhibited higher Proteobacteria abundance (57.16% and 66.58%, respectively) and reduced diversity of beneficial bacteria. Notably, the presence of sepsis was associated with an increase in pathogenic bacteria and a decrease in beneficial commensal bacteria. Neonates with sepsis exhibited significant gut microbiome dysbiosis, characterized by increased Proteobacteria and reduced beneficial bacteria diversity. These findings highlight the potential of microbiome profiling as a diagnostic tool and underscore the importance of gut microbiota modulation in managing neonatal sepsis.

Vertical transfer of gut microbiota from dam to neonate calf in the early of life

The aim of this study was to investigate the vertical transfer of microbiota from dams to the offspring. We studied a pair of 20 dams and its offspring. Maternal sources (colostrum, feces and vaginal secretion) and newborn fecal samples were analyzed using 16S rDNA amplicon sequencing on days 1, 3, 7, 14 and 28. Overall, newborns were maintained healthy and did not receive antimicrobial therapy. The Source Tracker analysis indicated that the newborn fecal microbiota was similar to colostrum and vaginal secretion from day 1 up to 7. However, an unknown source (probably from the environment) showed a gradual increase in its similarity with fecal samples from calves measured from day 3 to 28. The most abundant bacteria groups on meconium (day 1) and calf fecal samples on day 3 were Escherichia-Shigella and Clostridium, respectively. On day 7, the predominant genus were Bifidobacterium and Lactobacillus, while Fusobacterium was the most abundant genus on day 14, coinciding with the diarrhea peak. Faecalibacterium showed a gradual increase throughout the neonatal period. Maternal sources contribute to the neonatal microbiota, however other unknown sources (probably environment) had a strong influence on development of the gut microbiota later in the neonate period.

Primary succession of Bifidobacteria drives pathogen resistance in neonatal microbiota assembly

Human microbiota assembly commences at birth, seeded by both maternal and environmental microorganisms. Ecological theory postulates that primary colonizers dictate microbial community assembly outcomes, yet such microbial priority effects in the human gut remain underexplored. Here using longitudinal faecal metagenomics, we characterized neonatal microbiota assembly for a cohort of 1,288 neonates from the UK. We show that the pioneering neonatal gut microbiota can be stratified into one of three distinct community states, each dominated by a single microbial species and influenced by clinical and host factors, such as maternal age, ethnicity and parity. A community state dominated by Enterococcus faecalis displayed stochastic microbiota assembly with persistent high pathogen loads into infancy. In contrast, community states dominated by Bifidobacterium, specifically B. longum and particularly B. breve, exhibited a stable assembly trajectory and long-term pathogen colonization resistance, probably due to strain-specific functional adaptions to a breast milk-rich neonatal diet. Consistent with our human cohort observation, B. breve demonstrated priority effects and conferred pathogen colonization resistance in a germ-free mouse model. Our findings solidify the crucial role of Bifidobacteria as primary colonizers in shaping the microbiota assembly and functions in early life.

Effect of β-lactam antibiotics on the gut microbiota of term neonates

β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns’ gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery.

The Impact of Gestational Diabetes Mellitus (GDM) on the Development and Composition of the Neonatal Gut Microbiota: A Systematic Review.

Gestational diabetes mellitus (GDM) is an important health issue, as it is connected with adverse effects to the mother as well as the fetus. A factor of essence for the pathology of this disorder is the gut microbiota, which seems to have an impact on the development and course of GDM. The role of the gut microbiota on maternal reproductive health and all the changes that happen during pregnancy as well as during the neonatal period is of high interest. The correct establishment and maturation of the gut microbiota is of high importance for the development of basic biological systems. The aim of this study is to provide a systematic review of the literature on the effect of GDM on the gut microbiota of neonates, as well as possible links to morbidity and mortality of neonates born to mothers with GDM. Systematic research took place in databases including PubMed and Scopus until June 2024. Data that involved demographics, methodology, and changes to the microbiota were derived and divided based on patients with exposure to or with GDM. The research conducted on online databases revealed 316 studies, of which only 16 met all the criteria and were included in this review. Research from the studies showed great heterogeneity and varying findings at the level of changes in α and β diversity and enrichment or depletion in phylum, gene, species, and operational taxonomic units in the neonatal gut microbiota of infants born to mothers with GDM. The ways in which the microbiota of neonates and infants are altered due to GDM remain largely unclear and require further investigation. Future studies are needed to explore and clarify these mechanisms.

Effect of different delivery modes on intestinal microbiota and immune function of neonates

Different delivery methods can cause variations in the composition and structure of intestinal microbiota in neonates. However, the impact of the microecological environment on host immune function requires further investigation. In this study, 75 healthy neonates were divided into two groups: vaginal delivery group (n = 36) and cesarean section group (n = 39). Fecal and peripheral blood samples were collected from the 7th to the 10th day. 16S rRNA sequencing technique was performed to investigate the gut microbiota on fecal samples. Levels of immunoglobulins and Th1 and Th2 cells in the peripheral blood of neonates were measured. The abundance of Escherichia, Bifidobacterium, and Bacteroides in neonates in the cesarean section group was significantly lower than that in the vaginal delivery group. Metabolic pathway analysis showed three significantly up-regulated metabolic pathways in the intestinal microbiota of neonates in the cesarean section group. The levels of serum IgG and IL-12p70 in the cesarean section group were lower than those in the vaginal delivery group, and the proportion of IFN-γ/IL-4 was significantly lower in the cesarean section group compared to the vaginal delivery group. The mode of delivery has potential impact on the intestinal microbiota and immune functions of neonates, potentially leading to an imbalance of Th1/Th2 cells in neonates delivered by cesarean section.

Effects of dietary zinc on the gut microbiome and resistome of the gestating cow and neonatal calf

Zinc is an essential trace element required in the diet of all species. While the effects of zinc have been studied in growing calves, little is known about the effect of zinc on the microbiota of the gestating cow or her neonatal calf. Understanding factors that shape the gut health of neonatal animals and evaluating the effect of dietary supplements in adult gestating animals is important in promoting animal health and informing feeding practices. The aims of this study were to determine the effect of dietary zinc on the microbiota and resistome of the gestating cow and calf. Gestating cows received standard (40 ppm) or high (205 ppm) dietary zinc levels from dry off to calving. Fecal samples were collected from cows upon enrollment and at calving and from neonatal calves. Fecal samples underwent 16S rRNA sequencing and a subset also underwent shotgun metagenomic sequencing. The effect of zinc supplementation on the diversity and composition of the cow and calf microbiome and resistome was assessed. Alpha and beta diversity and composition of the microbiota were significantly altered over time but not by treatment in the cows, with alpha diversity decreasing and 14 genera found at significantly higher relative abundances at calving compared to enrollment. Levels of 27 antimicrobial resistance genes significantly increased over time. Only a small number of taxa were differentially expressed at calving in treatment and control groups, including Faecalibacterium, Bacteroides, Turicibacter, and Bifidobacterium pseudolongum. No effect of the dam’s treatment group was observed on the diversity or composition of the neonatal calf microbiota. The calf resistome, which was relatively rich and diverse compared to the cow, was also unaffected by the dam’s treatment group. The impact of high levels of dietary zinc thus appeared to be minimal, with no observed changes in alpha or beta diversity, and few changes in the relative abundance of a small number of taxa and antimicrobial resistance genes.

Neonatal microbiota colonization drives maturation of primary and secondary goblet cell mediated protection in the pre-weaning colon.

In the distal colon, mucus secreting goblet cells primarily confer protection from luminal microorganisms via generation of a sterile inner mucus layer barrier structure. Bacteria-sensing sentinel goblet cells provide a secondary defensive mechanism that orchestrates mucus secretion in response to microbes that breach the mucus barrier. Previous reports have identified mucus barrier deficiencies in adult germ-free mice, thus implicating a fundamental role for the microbiota in programming mucus barrier generation. In this study, we have investigated the natural neonatal development of the mucus barrier and sentinel goblet cell-dependent secretory responses upon postnatal colonization. Combined in vivo and ex vivo analyses of pre- and post-weaning colonic mucus barrier and sentinel goblet cell maturation demonstrated a sequential microbiota-dependent development of these primary and secondary goblet cell-intrinsic protective functions, with dynamic changes in mucus processing dependent on innate immune signalling via MyD88, and development of functional sentinel goblet cells dependent on the NADPH/Dual oxidase family member Duox2. Our findings therefore identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of colonic barrier function.

Iron capture through CD71 drives perinatal and tumor-associated Treg expansion.

Besides suppressing immune responses, regulatory T cells (Tregs) maintain tissue homeostasis and control systemic metabolism. Whether iron is involved in Treg-mediated tolerance is completely unknown. Here, we showed that the transferrin receptor CD71 was upregulated on activated Tregs infiltrating human liver cancer. Mice with a Treg-restricted CD71 deficiency spontaneously developed a scurfy-like disease, caused by impaired perinatal Treg expansion. CD71-null Tregs displayed decreased proliferation and tissue-Treg signature loss. In perinatal life, CD71 deficiency in Tregs triggered hepatic iron overload response, characterized by increased hepcidin transcription and iron accumulation in macrophages. Lower bacterial diversity, and reduction of beneficial species, were detected in the fecal microbiota of CD71 conditional knockout neonates. Our findings indicate that CD71-mediated iron absorption is required for Treg perinatal expansion and is related to systemic iron homeostasis and bacterial gut colonization. Therefore, we hypothesize that Tregs establish nutritional tolerance through competition for iron during bacterial colonization after birth.

The Association of Neonatal Gut Microbiota Community State Types with Birth Weight.

while most gut microbiota research has focused on term infants, the health outcomes of preterm infants are equally important. Very-low-birth-weight (VLBW) or extremely-low-birth-weight (ELBW) preterm infants have a unique gut microbiota structure, and probiotics have been reported to somewhat accelerate the maturation of the gut microbiota and reduce intestinal inflammation in very-low preterm infants, thereby improving their long-term outcomes. The aim of this study was to investigate the structure of gut microbiota in ELBW neonates to facilitate the early identification of different types of low-birth-weight (LBW) preterm infants. a total of 98 fecal samples from 39 low-birth-weight preterm infants were included in this study. Three groups were categorized according to different birth weights: ELBW (n = 39), VLBW (n = 39), and LBW (n = 20). The gut microbiota structure of neonates was obtained by 16S rRNA gene sequencing, and microbiome analysis was conducted. The community state type (CST) of the microbiota was predicted, and correlation analysis was conducted with clinical indicators. Differences in the gut microbiota composition among ELBW, VLBW, and LBW were compared. The value of gut microbiota composition in the diagnosis of extremely low birth weight was assessed via a random forest-machine learning approach. we briefly analyzed the structure of the gut microbiota of preterm infants with low birth weight and found that the ELBW, VLBW, and LBW groups exhibited gut microbiota with heterogeneous compositions. Low-birth-weight preterm infants showed five CSTs dominated by Enterococcus, Staphylococcus, Klebsiella, Streptococcus, Pseudescherichia, and Acinetobacter. The birth weight and clinical indicators related to prematurity were associated with the CST. We found the composition of the gut microbiota was specific to the different types of low-birth-weight premature infants, namely, ELBW, VLBW, and LBW. The ELBW group exhibited significantly more of the potentially harmful intestinal bacteria Acinetobacter relative to the VLBW and LBW groups, as well as a significantly lower abundance of the intestinal probiotic Bifidobacterium. Based on the gut microbiota's composition and its correlation with low weight, we constructed random forest model classifiers to distinguish ELBW and VLBW/LBW infants. The area under the curve of the classifiers constructed with Enterococcus, Klebsiella, and Acinetobacter was found to reach 0.836 by machine learning evaluation, suggesting that gut microbiota composition may be a potential biomarker for ELBW preterm infants. the gut bacteria of preterm infants showed a CST with Enterococcus, Klebsiella, and Acinetobacter as the dominant genera. ELBW preterm infants exhibit an increase in the abundance of potentially harmful bacteria in the gut and a decrease in beneficial bacteria. These potentially harmful bacteria may be potential biomarkers for ELBW preterm infants.

The association of maternal factors with the neonatal microbiota and health

The human microbiome plays a crucial role in human health. However, the influence of maternal factors on the neonatal microbiota remains obscure. Herein, our observations suggest that the neonatal microbiotas, particularly the buccal microbiota, change rapidly within 24–48 h of birth but begin to stabilize by 48–72 h after parturition. Network analysis clustered over 200 maternal factors into thirteen distinct groups, and most associated factors were in the same group. Multiple maternal factor groups were associated with the neonatal buccal, rectal, and stool microbiotas. Particularly, a higher maternal inflammatory state and a lower maternal socioeconomic position were associated with a higher alpha diversity of the neonatal buccal microbiota and beta diversity of the neonatal stool microbiota was influenced by maternal diet and cesarean section by 24–72 h postpartum. The risk of admission of a neonate to the newborn intensive care unit was associated with preterm birth as well as higher cytokine levels and probably higher alpha diversity of the maternal buccal microbiota.

Comparative Effect of Breast Milk and Infant Formulae on Neonatal Gut Microbiome within Katsina Metropolis

Study’s Novelty/ Excerpt This study explored the impact of breast milk versus infant formula on the gut microbiota of neonates in Katsina metropolis, revealing significant differences in bacterial composition and fecal pH between the two groups. Exclusively breastfed infants exhibited a lower fecal pH (5.09±0.1) and higher weights, with similar levels of Escherichia spp. and Bifidobacterium spp., while formula-fed infants showed a higher fecal pH (5.9±0.1) and differences in Escherichia spp. loads. Despite advances in infant formula enrichment, the study underscores the distinct influence of breast milk on neonatal gut microbiota composition and health. Full Abstract Numerous studies conducted in recent years have highlighted the intricate nature of the neonatal gut microbiome, influenced by various intrinsic and extrinsic factors. One significant factor in this regard is the type of feeding, which has a substantial impact on the development of intestinal microbiota in early infancy. This study aimed to compare the effects of breast milk and infant formulae on the gut microbiota of newborns in Katsina metropolis. Faecal samples were obtained from 46 neonates (33 exclusively breastfed, 10 formula-fed, and 3 mix-fed) and analyzed using a culture-dependent method. Colony enumerations and pH measurements were conducted for comparison between the groups. The mean weight of the participants was 2.88±0.1 kg, with exclusively breastfed infants (BFI) weighing significantly more (p = 0.03) than formula-fed infants (FFI). The bacteria selected for analysis (Bifidobacterium spp., Staphylococcus spp., Escherichia spp., and Lactobacillus spp.) were present in all feeding groups. Among BFI, similar levels of Escherichia spp. and Bifidobacterium spp. (61.17 CFU/g and 61.38 CFU/g respectively) were observed. Staphylococcus spp. constituted the majority of the bacterial load (32%) in both BFI and FFI groups. Apart from Escherichia spp. (p = 0.01), no significant differences were noted in the levels of all cultured bacteria across the feeding groups. The disparity in Escherichia spp. load was evident between BFI and MFI (p = 0.01), as well as FFI and MFI (p = 0.02) only. There was no overall significant correlation between bacterial load and mode of delivery within the feeding groups (p = 0.6). The average faecal pH of breastfed infants (5.09±01) was significantly lower (p = &lt;0.001) compared to the formula-fed group (5.9±0.1). Despite advancements in enriching infant formulae with probiotics and other bifidogenic substances, subtle differences in fecal bacterial load compared to breast milk persist, highlighting the significant influence of both feeding methods on the composition and functionality of the neonatal gut microbiome

The role of Bifidobacterium genus in modulating the neonate microbiota: implications for antibiotic resistance acquisition in early life

ABSTRACT Resistance to antibiotics in newborns is a huge concern as their immune system is still developing, and infections and resistance acquisition in early life have short- and long-term consequences for their health. Bifidobacterium species are important commensals capable of dominating the infant gut microbiome and are known to be less prone to possess antimicrobial resistance genes than other taxa that may colonize infants. We aimed to study the association between Bifidobacterium-dominated infant gut microbiota and the antibiotic resistant gene load in neonates, and to ascertain the perinatal factors that may contribute to the antibiotic resistance acquisition. Two hundred infant fecal samples at 7 days and 1 month of age from the MAMI birth cohort were included in the study and for whom maternal-neonatal clinical records were available. Microbiota profiling was carried out by 16S rRNA amplicon sequencing, and targeted antibiotic resistance genes (ARGs) including tetM, tetW, tetO, blaTEM, blaSHV and ermB were quantified by qPCR. Infant microbiota clustered into two distinct groups according to their Bifidobacterium genus abundance: high and low. The main separation of groups or clusters at each time point was performed with an unsupervised non-linear algorithm of k-means partitioning to cluster data by time points based on Bifidobacterium genus relative abundance. Microbiota composition differed significantly between both groups, and specific bifidobacterial species were enriched in each cluster. Lower abundance of Bifidobacterium in the infant gut was associated with a higher load of antibiotic resistance genes. Our results highlight the relevance of Bifidobacterium genus in the early acquisition and establishment of antibiotic resistance in the gut. Further studies are needed to develop strategies to promote a healthy early colonization and fight against the spread of antibiotic resistances.

State of the Art: Intrapartum Antibiotics in Cesarean Section—The Infant Microbiota and Allergic Diseases

(Acta Obstet Gynecol Scand. 2023;102:811–820) Recent changes in guidelines for administering maternal antibiotics for cesarean deliveries (CD) have increased neonatal exposure to antibiotics. Potential long-term effects of this exposure are relatively unknown; recent evidence in other fields has indicated a long-lasting impact of antibiotic exposure on gut microbiota composition, which raises concerns about the effects of antibiotics on the fragile and new gut microbiota of neonates around the time of birth. This review assessed the current guidelines and applications for CD antibiotics, as well as discussed the importance of neonatal intestinal microbiota and the potential consequences of antibiotic prophylaxis in the development of the neonatal immune system and allergic disease.

Analysis of the intestinal microbiota and profiles of blood amino acids and acylcarnitines in neonates with hyperbilirubinemia

ObjectiveThis study aimed to discuss the distinctive features of the intestinal microbiota in neonates with hyperbilirubinemia and to comprehensively analyse the composition of the intestinal microbiota as well as the levels of free amino acids and acylcarnitines in the peripheral blood of neonates experiencing hyperbilirubinemia.ResultsAt the phylum level, Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Chloroflexi were the five predominant microbial groups identified in both the hyperbilirubinemia and control groups. Alpha diversity analysis, encompassing seven indices, showed no statistically significant differences between the two groups. However, Beta diversity analysis revealed a significant difference in intestinal microbiota structure between the groups. Linear discriminant analysis effect size (LEfSe) indicated a significant reduction in the abundance of Gammaproteobacteria and Enterobacteriaceae within the hyperbilirubinemia group compared to that in the control group. The heatmap revealed that the control group exhibited increased abundances of Escherichia and Bifidobacterium, while the hyperbilirubinemia group exhibited increased levels of Enterococcus and Streptococcus. Regarding blood amino acids and acylcarnitines, there were greater concentrations of citrulline (Cit), arginine (Arg), ornithine (Orn), and valine (Val) in the hyperbilirubinemia group than in the control group. The hyperbilirubinemia group also exhibited significant increases in medium-chain fatty acids (C6, C8), long-chain fatty acids (C18), and free carnitine (C0).ConclusionBy comparing neonates with hyperbilirubinemia to those without, a significant disparity in the community structure of the intestinal microbiota was observed. The intestinal microbiota plays a crucial role in the bilirubin metabolism process. The intestinal microbiota of neonates with hyperbilirubinemia exhibited a certain degree of dysbiosis. The abundances of Bacteroides and Bifidobacterium were negatively correlated with the bilirubin concentration. Therefore, the fact that neonates with hyperbilirubinemia exhibit some variations in blood amino acid and acylcarnitine levels may provide, to a certain degree, a theoretical basis for clinical treatment and diagnosis.

180 Dietary milk fat globule membrane alters intestinal microbiota of neonatal piglet following lipopolysaccharide challenge and marker of neuroinflammation

Abstract Early life stress exposure can increase morbidity and reduce animal wellbeing throughout life. Dysregulated gut function has been associated with neurological changes, and neurological changes affect gut homeostasis. Maternal milk is the gold-standard for yielding developmental benefits to offspring. Identification of milk components has led to an understanding of the bioactive nutrients important in neonatal development. Components of the milk fat globule membrane (MFGM) contribute immensely to neonatal gut health and neurodevelopment. However, mechanisms of actions are still being defined. The objective is to understand how dietary MFGM modulates the gut microbiota, blood-brain barrier tight junctions, and brain inflammatory markers following lipopolysaccharide (LPS) challenge. Piglets (n = 24, one-d-old) were assigned to soy (CON) or MFGM phospholipid supplemented diet (0.75% wt/wt) ± LPS (100 µg/kg body weight) in a 2 × 2 factorial design (n = 6 animals•diet-1•challenge-1.). Piglets were fed for 21 d and 6 animals/diet received saline or LPS injections 4 h before euthanasia. Colonic microbiota was characterized through 16s rRNA gene sequencing, while hypothalamus samples were collected to evaluate brain barrier function and inflammation-related genes using RT-qPCR. Microbiota data were processed using QIIME2 with DADA2 plugin and analyzed for alpha-diversity, beta-diversity, and differential abundance in R software. Gene transcription data were analyzed by a 2 × 2 experimental factorial design using the PROC MIXED procedure of SAS. Principal coordinates analysis indicated that MFGM-fed groups exhibited an observable separation from CON-fed groups in terms of microbial community structures (P &amp;lt; 0.05). Firmicutes_A, Bacteroidota, and Firmicutes_D were the predominant phyla across all treatments, with average proportions to be 52.21 %, 24.36 %, and 18.46 %, respectively. At genus level, MFGM + Saline group down-regulated Corynebacterium by 88.00 % (q &amp;lt; 0.05) and Unclassified Muribaculaceae by 73.33 % (0.050.05). However, there was an MFGM × LPS interaction (P &amp;lt; 0.05) observed for nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor alpha, in which MFGM attenuated the LPS-induced increase in mRNA relative abundance (3.62 and 2.39 ± 0.38). In conclusion, dietary MFGM altered neonatal piglet intestinal microbiota and an important signaling molecule of the neuroinflammatory response following LPS challenge.

Gut Microbiota and Symptom Expression and Severity in Neonatal Abstinence Syndrome.

Problem: Neonatal abstinence syndrome (NAS) affecting neonates with fetal exposure to opioids, is defined by expression and severity of symptoms. The pathophysiology behind symptoms variability is lacking. The study aims were to examine (a) differences in gut microbiota of neonates with and without NAS, (b) the relationships between gut microbiota and symptom expression and NAS severity, and (c) the changes in the neonate gut microbiota diversity during the course of NAS treatment. Methods: A cross-sectional observational design was used to examine differences in microbiota and a longitudinal, repeated measures approach was used to determine relationships between gut microbiota and NAS symptoms. Symptom data were collected using the Finnegan Neonatal Abstinence Scoring Tool and the Neonatal Pain Agitation and Sedation Scale. Stool samples were collected for microbiome analyses with 16S rRNA microbiome sequencing. Results: Differences in alpha and beta diversity between neonates with and without NAS were seen. Relative abundance results revealed 18 taxa were different in neonates with NAS compared to neonates without NAS. No differences were found in alpha or beta diversity in neonates with NAS between enrollment and hospital discharge. There was increased abundance of Escherichia-Shigella and Bacteriodes genera related to higher symptom scores. Discussion: Differences in alpha and beta diversity between neonates with and without NAS may be due to differences in birth mode and type of feeding. The findings of specific increased bacteria related to increased symptoms in the neonates with NAS may also be influenced by birth mode and type of feeding.