Unfavourable intrauterine environment contributes to abnormal gut microbiome and metabolome in twins

Spatiotemporal patterns of the pregnancy microbiome and links to reproductive disorders

The microbiome of females undergoes extensive remodeling during pregnancy, which is likely to have an impact on the health of both mothers and offspring. Nevertheless, large-scale integrated investigations characterizing microbiome dynamics across key body habitats are lacking. Here, we performed an extensive meta-analysis that compiles and analyzes microbiome profiles from  >10,000 samples across the gut, vagina, and oral cavity of pregnant women from diverse geographical regions. We have unveiled unexpected variations in the taxonomic, functional, and ecological characteristics of microbial communities throughout the course of pregnancy. The gut microbiota showed distinct trajectories between Western and non-Western populations. The vagina microbiota exhibited fluctuating transitions at the genus level across gestation, while the oral microbiota remained relatively stable. We also identified distinctive microbial signatures associated with prevalent pregnancy-related disorders, including opposite variations in the oral and gut microbiota of patients with gestational diabetes and disrupted microbial networks in preterm birth. This study establishes a comprehensive atlas of the pregnancy microbiome by integrating multidimensional datasets and offers foundational insights into the intricate interplay between microbes and host factors that underlie reproductive health.

Effect of Laryngopharyngeal Reflux and Potassium-Competitive Acid Blocker (P-CAB) on the Microbiological Comprise of the Laryngopharynx

OBJECTIVE

To probe the microbiota composition progressing from healthy individuals to those with laryngopharyngeal reflux disease (LPRD) and subsequently undergoing potassium-competitive acid inhibitor (P-CAB) therapy.

STUDY DESIGN

Prospective case-control study.

SETTING

Academic Medical Center.

METHODS

Forty patients with LPRD and 51 patients without LPRD were recruited. An 8-week P-CAB therapy was initiated (post-T-LPRD), and 39 had return visits. In total, 130 laryngopharyngeal saliva samples were collected and sequenced by targeting the V3-V4 region of the 16S ribosomal RNA (rRNA) gene using an Illumina MiSeq. Amplicon sequence variants (ASVs) and clinical indices were analyzed.

RESULTS

Alpha and beta diversities were compared among the non-LPRD, LPRD, and post-T-LPRD groups, and the Observed_ASVs were not significantly different. At the same time, the Shannon and Simpson indices, unweighted Unifrac, weighted Unifrac, and binary Jaccard distance were significantly different between non-LPRD and LPRD groups. In addition, significant differences were found in the abundance of Streptococcus, Prevotella, and Prevotellaceae in the LPRD versus non-LPRD groups, and Neisseria, Leptotrichia, and Allprevotella in the LPRD versus post-T-LPRD groups. The genera model was used to distinguish patients with LPRD from those without, and a better receiver operating characteristic curve was formed after combining the clinical indices of reflux symptom index, reflux finding score, and pepsin, with an area under the curve of 0.960.

CONCLUSION

Laryngopharyngeal microbial communities changed after laryngopharyngeal reflux and were modified further after P-CAB treatment, which provides a potential diagnostic value for LPRD, especially when combined with clinical indices.

Microbiome and pregnancy: focus on microbial dysbiosis coupled with maternal obesity

Obesity is becoming a worldwide pandemic with over one billion people affected. Of women in the United States, who are of childbearing age, two-thirds of them are considered overweight/obese. Offspring of women with obesity have a greater likelihood of developing cardiometabolic disease later in life, therefore making obesity a transgenerational issue. Emerging topics such as maternal microbial dysbiosis with altered levels of bacterial phyla and maternal obesity programming offspring cardiometabolic disease are a novel area of research discussed in this review. In the authors' opinion, beneficial therapeutics will be developed from knowledge of bacterial-host interactions at the most specific level possible. Although there is an abundance of obesity-related microbiome research, it is not concise, readily available, nor easy to interpret at this time. This review details the current knowledge regarding the relationship between obesity and the gut microbiome, with an emphasis on maternal obesity.

Effect of gut microbiome modulation on muscle function and cognition: the PROMOTe randomised controlled trial

Studies suggest that inducing gut microbiota changes may alter both muscle physiology and cognitive behaviour. Gut microbiota may play a role in both anabolic resistance of older muscle, and cognition. In this placebo controlled double blinded randomised controlled trial of 36 twin pairs (72 individuals), aged ≥60, each twin pair are block randomised to receive either placebo or prebiotic daily for 12 weeks. Resistance exercise and branched chain amino acid (BCAA) supplementation is prescribed to all participants. Outcomes are physical function and cognition. The trial is carried out remotely using video visits, online questionnaires and cognitive testing, and posting of equipment and biological samples. The prebiotic supplement is well tolerated and results in a changed gut microbiome [e.g., increased relative Bifidobacterium abundance]. There is no significant difference between prebiotic and placebo for the primary outcome of chair rise time (β = 0.579; 95% CI -1.080-2.239 p = 0.494). The prebiotic improves cognition (factor score versus placebo (β = -0.482; 95% CI,-0.813, -0.141; p = 0.014)). Our results demonstrate that cheap and readily available gut microbiome interventions may improve cognition in our ageing population. We illustrate the feasibility of remotely delivered trials for older people, which could reduce under-representation of older people in clinical trials. ClinicalTrials.gov registration: NCT04309292.

Gut microbiota contributes to bisphenol A-induced maternal intestinal and placental apoptosis, oxidative stress, and fetal growth restriction in pregnant ewe model by regulating gut-placental axis

BACKGROUND

Bisphenol A (BPA) is an environmental contaminant with endocrine-disrupting properties that induce fetal growth restriction (FGR). Previous studies on pregnant ewes revealed that BPA exposure causes placental apoptosis and oxidative stress (OS) and decreases placental efficiency, consequently leading to FGR. Nonetheless, the response of gut microbiota to BPA exposure and its role in aggravating BPA-mediated apoptosis, autophagy, mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and OS of the maternal placenta and intestine are unclear in an ovine model of gestation.

RESULTS

Two pregnant ewe groups (n = 8/group) were given either a subcutaneous (sc) injection of corn oil (CON group) or BPA (5 mg/kg/day) dissolved in corn oil (BPA group) once daily, from day 40 to day 110 of gestation. The maternal colonic digesta and the ileum and placental tissue samples were collected to measure the biomarkers of autophagy, apoptosis, mitochondrial dysfunction, ERS, and OS. To investigate the link between gut microbiota and the BPA-induced FGR in pregnant ewes, gut microbiota transplantation (GMT) was conducted in two pregnant mice groups (n = 10/group) from day 0 to day 18 of gestation after removing their intestinal microbiota by antibiotics. The results indicated that BPA aggravates apoptosis, ERS and autophagy, mitochondrial function injury of the placenta and ileum, and gut microbiota dysbiosis in pregnant ewes. GMT indicated that BPA-induced ERS, autophagy, and apoptosis in the ileum and placenta are attributed to gut microbiota dysbiosis resulting from BPA exposure.

CONCLUSIONS

Our findings indicate the underlying role of gut microbiota dysbiosis and gut-placental axis behind the BPA-mediated maternal intestinal and placental apoptosis, OS, and FGR. The findings further provide novel insights into modulating the balance of gut microbiota through medication or probiotics, functioning via the gut-placental axis, to alleviate gut-derived placental impairment or FGR. Video Abstract.

Metabolic and fecal microbial changes in adult fetal growth restricted mice

BACKGROUND

Fetal growth restriction (FGR) increases risk for development of obesity and type 2 diabetes. Using a mouse model of FGR, we tested whether metabolic outcomes were exacerbated by high-fat diet challenge or associated with fecal microbial taxa.

METHODS

FGR was induced by maternal calorie restriction from gestation day 9 to 19. Control and FGR offspring were weaned to control (CON) or 45% fat diet (HFD). At age 16 weeks, offspring underwent intraperitoneal glucose tolerance testing, quantitative MRI body composition assessment, and energy balance studies. Total microbial DNA was used for amplification of the V4 variable region of the 16 S rRNA gene. Multivariable associations between groups and genera abundance were assessed using MaAsLin2.

RESULTS

Adult male FGR mice fed HFD gained weight faster and had impaired glucose tolerance compared to control HFD males, without differences among females. Irrespective of weaning diet, adult FGR males had depletion of Akkermansia, a mucin-residing genus known to be associated with weight gain and glucose handling. FGR females had diminished Bifidobacterium. Metabolic changes in FGR offspring were associated with persistent gut microbial changes.

CONCLUSION

FGR results in persistent gut microbial dysbiosis that may be a therapeutic target to improve metabolic outcomes.

IMPACT

Fetal growth restriction increases risk for metabolic syndrome later in life, especially if followed by rapid postnatal weight gain. We report that a high fat diet impacts weight and glucose handling in a mouse model of fetal growth restriction in a sexually dimorphic manner. Adult growth-restricted offspring had persistent changes in fecal microbial taxa known to be associated with weight, glucose homeostasis, and bile acid metabolism, particularly Akkermansia, Bilophilia and Bifidobacteria. The gut microbiome may represent a therapeutic target to improve long-term metabolic outcomes related to fetal growth restriction.

MAMI: a comprehensive database of mother-infant microbiome and probiotic resources

Extensive evidence has demonstrated that the human microbiome and probiotics confer great impacts on human health, particularly during critical developmental stages such as pregnancy and infancy when microbial communities undergo remarkable changes and maturation. However, a major challenge in understanding the microbial community structure and interactions between mothers and infants lies in the current lack of comprehensive microbiome databases specifically focused on maternal and infant health. To address this gap, we have developed an extensive database called MAMI (Microbiome Atlas of Mothers and Infants) that archives data on the maternal and neonatal microbiome, as well as abundant resources on edible probiotic strains. By leveraging this resource, we can gain profound insights into the dynamics of microbial communities, contributing to lifelong wellness for both mothers and infants through precise modulation of the developing microbiota. The functionalities incorporated into MAMI provide a unique perspective on the study of the mother-infant microbiome, which not only advance microbiome-based scientific research but also enhance clinical practice. MAMI is publicly available at https://bioinfo.biols.ac.cn/mami/.

Evidence for ethnicity and location as regulators of the newborn blood metabolome: a monozygous twin study

Introduction

Monochorionic, diamniotic (MCDA) monozygotic twins share nearly all genetic variation and a common placenta in utero. Despite this, MCDA twins are often discordant for a range of common phenotypes, including early growth and birth weight. As such, MCDA twins represent a unique model to explore variation in early growth attributable primarily to in utero environmental factors.

Methods

MCDA twins with a range of within-pair birth weight discordance were sampled from the peri/postnatal epigenetic twin study (PETS, Melbourne; n = 26 pairs), Beijing twin study (BTS, Beijing; n = 25), and the Chongqing longitudinal twin study (LoTiS, Chongqing; n = 22). All PETS participants were of European-Australian ancestry, while all Chinese participants had Han ancestry. The average of the birth weight difference between the larger and smaller co-twins for all twin pairs was determined and metabolomic profiles of amino acids, TCA cycle intermediates, fatty acids, organic acids, and their derivatives generated from cord blood plasma by gas chromatograph mass spectrometry. Within and between co-twin pair analyses were performed to identify metabolites specifically associated with discordance in birth weight. Multivariable regression and pathway enrichment analyses between different regions were performed to evaluate the geographical effects on the metabolism of MCDA twin pairs.

Results

PETS twins showed a markedly different metabolic profile at birth compared to the two Chinese samples. Within-pair analysis revealed an association of glutathione, creatinine, and levulinic acid with birth weight discordance. Caffeine, phenylalanine, and several saturated fatty acid levels were uniquely elevated in PETS twins and were associated with maternal BMI and average within pair birth weight, in addition to birth weight discordance. LoTiS twins had higher levels of glutathione, tyrosine, and gamma-linolenic acid relative to PETS and BTS twins, potentially associated with eating habits.

Conclusion

This study highlights the potential role of underlying genetic variation (shared by MZ twins), in utero (non-shared by MZ twins) and location-specific (shared by MZ twins) environmental factors, in regulating the cord blood metabolome of uncomplicated MCDA twins. Future research is needed to unravel these complex relationships that may play a key role in phenotypic metabolic alterations of twins independent of genetic diversity.

Amniotic fluid metabolic fingerprinting contributes to shaping the unfavourable intrauterine environment in monochorionic diamniotic twins

BACKGROUND & AIMS

Amniotic fluid (AF) is the primary intrauterine environment for fetal growth throughout gestation. Selective fetal growth restriction (sFGR) is an adverse complication characterized by unequal growth in twins with nearly identical genetic makeup. However, the influence of AF-mediated intrauterine environment on the development and progression of sFGR remains unexplored.

METHODS

High-throughput targeted metabolomics analysis (G350) was performed on AF samples collected from sFGR (n = 18) and MCDA twins with birth weight concordance (MCDA-C, n = 20) cases. Weighted correlation network analysis (WGCNA) was used to identify clinical features that may influence the metabolite composition in AF. Subsequently, partial least-squares discriminant analysis (PLS-DA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to compare the different types of sFGR and MCDA-C twins. Receiver operating characteristic (ROC) and multivariate ROC curves were utilized to explore potential AF markers in twins with sFGR.

RESULTS

In our study, 182 metabolites were quantified in 76 AF samples. WGCNA indicated that the metabolite composition in late AF may not be influenced by gestational age. PLSDA demonstrated distinct variations between the metabolite profiles of AF in the sFGR and MCDA-C twins, with a significant emphasis on amino acids as the primary differential metabolite. The dissimilarities observed in sFGR twins were predominantly attributed to lipid metabolism-related metabolites. In particular, the KEGG enrichment metabolic pathway analysis revealed significant associations of both types of sFGR twins with central carbon metabolism in cancer. The multivariate ROC curves indicated that the combination of carnosine, sarcosine, l-alanine, beta-alanine, and alpha-n-phenylacetylglutamine significantly improved the AUC to 0.928. Notably, the ROC curves highlighted creatine (AUC:0.934) may be a potential biomarker for severe sFGR.

CONCLUSION

The data presented in this study offer a comprehensive metabolic map of the AF in cases of sFGR, shedding light on potential biomarkers associated with fetal growth and development in MCDA twins.

Metabolic dynamics and prediction of sFGR and adverse fetal outcomes: a prospective longitudinal cohort study

BACKGROUND

Selective fetal growth restriction (sFGR) is an extreme complication that significantly increases the risk of perinatal mortality and long-term adverse neurological outcomes in offspring, affecting approximately 15% of monochorionic diamniotic (MCDA) twin pregnancies. The lack of longitudinal cohort studies hinders the early prediction and intervention of sFGR.

METHODS

We constructed a prospective longitudinal cohort study of sFGR, and quantified 25 key metabolites in 337 samples from maternal plasma in the first, second, and third trimester and from cord plasma. In particular, our study examined fetal growth and brain injury data from ultrasonography and used the Ages and Stages Questionnaire-third edition subscale (ASQ-3) to evaluate the long-term neurocognitive behavioral development of infants aged 2-3 years. Furthermore, we correlated metabolite levels with ultrasound data, including physical development and brain injury indicators, and ASQ-3 data using Spearman's-based correlation tests. In addition, special combinations of differential metabolites were used to construct predictive models for the occurrence of sFGR and fetal brain injury.

RESULTS

Our findings revealed various dynamic patterns for these metabolites during pregnancy and a maximum of differential metabolites between sFGR and MCDA in the second trimester (n = 8). The combination of L-phenylalanine, L-leucine, and L-isoleucine in the second trimester, which were closely related to fetal growth indicators, was highly predictive of sFGR occurrence (area under the curve [AUC]: 0.878). The combination of L-serine, L-histidine, and L-arginine in the first trimester and creatinine in the second trimester was correlated with long-term neurocognitive behavioral development and showed the capacity to identify fetal brain injury with high accuracy (AUC: 0.94).

CONCLUSIONS

The performance of maternal plasma metabolites from the first and second trimester is superior to those from the third trimester and cord plasma in discerning sFGR and fetal brain injury. These metabolites may serve as useful biomarkers for early prediction and promising targets for early intervention in clinical settings.

Gut Microbiota, Inflammation, and Probiotic Supplementation in Fetal Growth Restriction-A Comprehensive Review of Human and Animal Studies

Fetal growth restriction (FGR) is a pathological state that represents a fetus's inability to achieve adequate growth during pregnancy. Several maternal, placental, and fetal factors are likely associated with FGR etiology. FGR is linked to severe fetal and neonatal complications, as well as adverse health consequences in adulthood. Numerous randomized controlled trials (RCTs) have demonstrated improved growth in FGR fetuses with promising treatment strategies such as maternal micronutrient, amino acid, and nitric oxide supplementation. Elevated inflammation in pregnant women diagnosed with FGR has been associated with an imbalance between pro- and anti-inflammatory cytokines. Gut microbiota dysbiosis may result in increased FGR-related inflammation. Probiotic treatment may relieve FGR-induced inflammation and improve fetal growth. The aim of this review is to provide an overview of the gut microbiota and inflammatory profiles associated with FGR and explore the potential of probiotics in treating FGR.

Oropharyngeal administration of colostrum targeting gut microbiota and metabolites in very preterm infants: protocol for a multicenter randomized controlled trial

BACKGROUND

Oropharyngeal administration of colostrum (OAC) has an immune-stimulating effect on oropharyngeal-associated lymphoid tissue, and can promote the maturation of the gastrointestinal tract. However, how OAC promotes intestinal maturation in preterm infants by altering gut microbiota remains unclear. We aim to assess changes in gut microbiota and metabolites after OAC in very preterm infants.

METHODS

A multicenter, double-blind, randomized controlled trial will be conducted in three large neonatal intensive care units in Shenzhen, China, with preterm infants with gestational age less than 32 weeks at birth and birth weight less than 1500 g. It is estimated that 320 preterm infants will be enrolled in this study within one year. The intervention group will receive oropharyngeal administration of 0.2 ml colostrum every 3 h, starting between the first 48 to 72 h and continued for 5 consecutive days. Following a similar administration scheme, the control group will receive oropharyngeal administration of sterile water. Stool samples will be collected at the first defecation, as well as on the 7th, 14th, 21st and 28th days after birth for analysis of effect of OAC on gut microbiota and metabolites through 16sRNA gene sequencing and liquid chromatography-mass spectrometry.

DISCUSSION

This proposal advocates for the promotion of OAC as a safe and relatively beneficial protocol in neonatal intensive care units, which may contribute to the establishment of a dominant intestinal flora. Findings of this study may help improve the health outcomes of preterm infants by establishment of targeted gut microbiota in future studies.

TRIAL REGISTRATION

NCT05481866 (registered July 30, 2022 on ClinicalTrials.gov).

Bacterial Colonization in the Airways and Intestines of Twin and Singleton Preterm Neonates: A Single-Center Study

Limited studies have investigated the microbial colonization of the airways and intestines in preterm neonates. We studied the composition of intestinal and airway bacterial colonies in several preterm twin pairs and singletons to explore the dominant bacteria, assess their variability, and predict their phenotypic and metabolic functions. In this descriptive study, we collected sputum and fetal stool specimens from 10 twin pairs (20 cases) and 20 singleton preterm neonates. These specimens were analyzed using 16S rRNA deep sequencing to study the alpha and beta diversities and community structures of airway and intestinal bacteria and predict their metabolic functions. Specimens from twins and singleton neonates had distinct aggregations of intestinal and airway bacteria but showed similarities and high microbial diversities during initial colonization. The top five phyla were Proteobacteria, Firmicutes, Actinobacteriota, Bacteroidota, and Cyanobacteria. The top ten genera were Streptococcus, Acinetobacter, Ralstonia, Staphylococcus, Comamonas, Enterococcus, Stenotrophomonas, Dechlorosoma, Sphingopyxis, and Rothia. Potentially pathogenic and highly stress-tolerant Gram-negative bacteria were predominant in the intestinal flora. A considerable proportion of colonies recovered from the airway and intestines of preterm neonates were functional bacteria. The richness of the intestinal and airway flora was not significantly different between twins and singletons, and the flora clustered together. Both intestinal and airway bacteria of twins and singletons were similar. The species involved in initial colonization were similar but different in proportions; therefore, changes in microbial structure and richness may not be attributed to these species.

Comparative Analysis of the Placental Microbiome in Pregnancies with Late Fetal Growth Restriction versus Physiological Pregnancies

A comparative analysis of the placental microbiome in pregnancies with late fetal growth restriction (FGR) was performed with normal pregnancies to assess the impact of bacteria on placental development and function. The presence of microorganisms in the placenta, amniotic fluid, fetal membranes and umbilical cord blood throughout pregnancy disproves the theory of the "sterile uterus". FGR occurs when the fetus is unable to follow a biophysically determined growth path. Bacterial infections have been linked to maternal overproduction of pro-inflammatory cytokines, as well as various short- and long-term problems. Proteomics and bioinformatics studies of placental biomass allowed the development of new diagnostic options. In this study, the microbiome of normal and FGR placentas was analyzed by LC-ESI-MS/MS mass spectrometry, and the bacteria present in both placentas were identified by analysis of a set of bacterial proteins. Thirty-six pregnant Caucasian women participated in the study, including 18 women with normal pregnancy and eutrophic fetuses (EFW > 10th percentile) and 18 women with late FGR diagnosed after 32 weeks of gestation. Based on the analysis of the proteinogram, 166 bacterial proteins were detected in the material taken from the placentas in the study group. Of these, 21 proteins had an exponentially modified protein abundance index (emPAI) value of 0 and were not included in further analysis. Of the remaining 145 proteins, 52 were also present in the material from the control group. The remaining 93 proteins were present only in the material collected from the study group. Based on the proteinogram analysis, 732 bacterial proteins were detected in the material taken from the control group. Of these, 104 proteins had an emPAI value of 0 and were not included in further analysis. Of the remaining 628 proteins, 52 were also present in the material from the study group. The remaining 576 proteins were present only in the material taken from the control group. In both groups, we considered the result of ns prot ≥ 60 as the cut-off value for the agreement of the detected protein with its theoretical counterpart. Our study found significantly higher emPAI values of proteins representative of the following bacteria: Actinopolyspora erythraea, Listeria costaricensis, E. coli, Methylobacterium, Acidobacteria bacterium, Bacteroidetes bacterium, Paenisporsarcina sp., Thiodiazotropha endol oripes and Clostridiales bacterium. On the other hand, in the control group statistically more frequently, based on proteomic data, the following were found: Flavobacterial bacterium, Aureimonas sp. and Bacillus cereus. Our study showed that placental dysbiosis may be an important factor in the etiology of FGR. The presence of numerous bacterial proteins present in the control material may indicate their protective role, while the presence of bacterial proteins detected only in the material taken from the placentas of the study group may indicate their potentially pathogenic nature. This phenomenon is probably important in the development of the immune system in early life, and the placental microbiota and its metabolites may have great potential in the screening, prevention, diagnosis and treatment of FGR.

Microbial transmission, colonisation and succession: from pregnancy to infancy

The microbiome has been proven to be associated with many diseases and has been used as a biomarker and target in disease prevention and intervention. Currently, the vital role of the microbiome in pregnant women and newborns is increasingly emphasised. In this review, we discuss the interplay of the microbiome and the corresponding immune mechanism between mothers and their offspring during the perinatal period. We aim to present a comprehensive picture of microbial transmission and potential immune imprinting before and after delivery. In addition, we discuss the possibility of in utero microbial colonisation during pregnancy, which has been highly debated in recent studies, and highlight the importance of the microbiome in infant development during the first 3 years of life. This holistic view of the role of the microbial interplay between mothers and infants will refine our current understanding of pregnancy complications as well as diseases in early life and will greatly facilitate the microbiome-based prenatal diagnosis and treatment of mother-infant-related diseases.

Necrotizing Enterocolitis: The Role of Hypoxia, Gut Microbiome, and Microbial Metabolites

Necrotizing enterocolitis (NEC) is a life-threatening disease that predominantly affects very low birth weight preterm infants. Development of NEC in preterm infants is accompanied by high mortality. Surgical treatment of NEC can be complicated by short bowel syndrome, intestinal failure, parenteral nutrition-associated liver disease, and neurodevelopmental delay. Issues surrounding pathogenesis, prevention, and treatment of NEC remain unclear. This review summarizes data on prenatal risk factors for NEC, the role of pre-eclampsia, and intrauterine growth retardation in the pathogenesis of NEC. The role of hypoxia in NEC is discussed. Recent data on the role of the intestinal microbiome in the development of NEC, and features of the metabolome that can serve as potential biomarkers, are presented. The Pseudomonadota phylum is known to be associated with NEC in preterm neonates, and the role of other bacteria and their metabolites in NEC pathogenesis is also discussed. The most promising approaches for preventing and treating NEC are summarized.

Bovine neonatal microbiome origins: a review of proposed microbial community presence from conception to colostrum

In recent years, there has been an influx of research evaluating the roles of the reproductive tract microbiota in modulating reproductive performance. These efforts have resulted in a breadth of research exploring the bovine reproductive tract microbiota. The female reproductive tract microbiota has been characterized during the estrus cycle, at timed artificial insemination, during gestation, and postpartum. Additionally, there are recently published studies investigating in-utero inoculation of the bovine fetus. However, critical review of the literature to understand how the microbial shifts during a dam's lifecycle could impact neonatal outcomes is limited. This review demonstrates a consistency at the phyla level throughout both the maternal, paternal, and neonatal microbiomes. Moreover, this review challenges the current gestational inoculation hypothesis and suggests instead a maturation of the resident uterine microbiota throughout gestation to parturition. Recent literature is indicative of microbial composition influencing metabolomic parameters that have developmental programming effects in feed utilization and metabolic performance later in life. Thus, this review enumerates the potential origins of neonatal microbial inoculation from conception, through gestation, parturition, and colostrum consumption while introducing clear paucities where future research is needed to better understand the ramifications of the reproductive microbiome on neonates.

Dilemmas in initiation of very preterm infant enteral feeds-when, what, how?

With limited clinical evidence available to guide common nutritional decisions, significant variation exists in approaches to enteral feeding for very preterm infants, specifically when feedings are initiated, what is fed, and the method used for feedings. Preclinical studies have highlighted the benefits associated with avoiding nil per os and providing early-stage mother's own milk or colostrum. However, these recommended approaches are often mutually exclusive due to the delays in lactation associated with very preterm delivery, resulting in uncertainty regarding which approach should be prioritized. Few studies have evaluated feeding frequency in preterm infants, with limited generalizability to extremely preterm infants. Therefore, even evidence-based approaches to very preterm infant feed initiation can differ. Future research is needed to identify optimal strategies for enteral nutrition in very preterm infants, but, until then, evidence-informed approaches may vary depending on each neonatal intensive care unit's assessment of risk and benefit.

The road not taken: host genetics in shaping intergenerational microbiomes

The early-life gut microbiome is linked to human phenotypes as an imbalanced microbiome of this period is implicated in diseases throughout life. Several determinants of early-life gut microbiome are explored, however, mechanisms of acquisition, colonization, and stability of early-life gut microbiome and their interindividual variability remain elusive. Host genetics play a vital role to shape the gut microbiome and interact with it to modulate individual phenotypes in human studies and animal models. Given the microbial linkage between host generations, we discuss the current state of roles of host genetics in forming intergenerational microbiomes associated with mothers, offspring, and those vertically transmitted, providing a basis for taking into account host genetics in future early-life microbiome research. We further expand our discussion to the bidirectional interactions between host gene expression and microbiome in human health.

Changes in the Gut Microbiome and Pathologies in Pregnancy

Pregnancy is a special period in a woman's life when her organism undergoes multiple physiological changes so that the fetus has optimal conditions for growth and development. These include modifications in the composition of the microbiome that occur between the first and third trimesters of pregnancy. There is an increase in Akkermansia, Bifidobacterium, and Firmicutes, which have been associated with an increase in the need for energy storage. The growth in Proteobacteria and Actinobacteria levels has a protective effect on both the mother and the fetus via proinflammatory mechanisms. The aim of the study is to review the research on the relationship between the mother's intestinal microbiome and gestational pathologies. Changes in the maternal gut microbiome is probably one of the mechanisms that occurs in various pregnancy diseases such as preeclampsia, fetal growth restriction, gestational diabetes mellitus, excessive gestational weight gain, and premature birth. For this reason, it seems vital to pay attention to certain interventions that can benefit the affected patients both in the short term, by preventing complications during pregnancy, and in the long term, as one of the mechanisms occurring in various gestational diseases is dysbiosis of the maternal intestinal flora.

Impacts of Delivery Mode and Maternal Factors on Neonatal Oral Microbiota

Objectives

Initial oral microbial colonization has complicatedly interacted with growth and development. The aim of our study was to discover links between oral microbiota community structure and mode of delivery, maternal factors, such as systemic diseases, abortion history, and pregnancy complications.

Methods

A total of 177 pregnant women and their neonates were enrolled at Peking university people’s hospital. We collected oral samples, medical history, and development phenotype and used a 16S rRNA gene sequence to analyze microbial diversity at all taxonomic levels, network structure, and metabolic characteristics.

Results

Firmicutes, Proteobacteria, and Actinobacteriota were the most predominant bacteria of neonatal oral samples among these phyla. Alpha-diversity of pregnant women with gestational diabetes mellitus (GDM), abortion history, and without immune diseases was higher than in control groups, and no significant dissimilarity in beta-diversity was observed between different maternal factors. Obvious separation or trend failed to be seen in different development phenotype groups. Besides, Oscillospirales were significantly more abundant in a natural delivery group than in the cesarean section group.

Conclusion

Our study indicated that maternal factors and mode of delivery influenced the oral microbial structure, but longitudinal studies were indispensable for capturing the long-term effects on neonatal development phenotype and oral microbiota.

The interplay of gut microbiota between donors and recipients determines the efficacy of fecal microbiota transplantation

Fecal microbiota transplantation (FMT) is a promising treatment for microbiota dysbiosis associated diseases, such as Clostridioides difficile infection (CDI) and inflammatory bowel disease (IBD). The engraftment of donor bacteria is essential for the effectiveness of FMT, which to some extent depends on the matching of donors and recipients. However, how different types of donor-derived bacteria affect FMT efficacy has not been fully dissected. We recruited two longitudinal IBD cohorts of 103 FMT recipients and further analyzed 1,280 microbiota datasets from 14 public CDI and IBD studies to uncover the effect of donor-derived microbiota in recipients. We found that two enterotypes, RCPT/E and RCPT/B (dominated by Enterobacteriaceae and Bacteroides, respectively), consistently exist in both CDI and IBD patients. Based on a time-course-based multi-cohort analysis of FMT fecal samples, we observed the interplay between recipient and donor-derived microbiota during FMT, in which the FMT outcome was significantly associated with the enterotype and microbiota distance between donor and recipient after FMT. We proposed a new measurement, the ratio of colonizers to residents after FMT (C2R), to quantify the engraftment of donor-derived bacteria in the recipients, and then constructed an enterotype-based statistical model for donor-recipient matching, which was validated by both cross-validation and an additional IBD FMT cohort (n = 42). We believe that with the accumulation of FMT multi-omics datasets, machine learning-based methods will be helpful for rational donor selection for improving efficacy and precision FMT practices.