Relationships Between Perinatal Interventions, Maternal-Infant Microbiomes, and Neonatal Outcomes

Nutrition and the gut-brain axis in neonatal brain injury and development

Early nutritional exposures, including during embryogenesis and the immediate postnatal period, affect offspring outcomes in both the short- and long-term. Alterations of these modifiable exposures shape the developing gut microbiome, intestinal development, and even neurodevelopmental outcomes. A gut-brain axis exists, and it is intricately connected to early life feeding and nutritional exposures. Here, we seek to discuss the (1) origins of the gut-brain access and relationship with neurodevelopment, (2) components of human milk (HM) beyond nutrition and their role in the developing newborn, and (3) clinical application of nutritional practices, including fluid management and feeding on the development of the gut-brain axis, and long-term neurodevelopmental outcomes. We conclude with a discussion on future directions and unanswered questions that are critical to provide further understanding and insight into how clinicians and healthcare providers can optimize early nutritional practices to ensure children not only survive, but thrive, free of neurodevelopmental impairment.

Probiotics, Prebiotics, Lactoferrin, and Combination Products to Prevent Mortality and Morbidity in Preterm Infants

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Impact of Kangaroo Mother Care on Skin Microbiome of Very Preterm Infants - A Pilot Study

OBJECTIVES

To test whether Kangaroo mother care (KMC) aids in transfer of favourable skin microbiome from mother to infant by comparing the microbiome composition before and after KMC.

METHODS

A prospective cohort pilot study was conducted in a Level III neonatal intensive care unit (NICU) in South India, recruiting 30 preterm infants with gestation <32 wk from October 2020 through December 2020. Neonatal skin involving the area in contact with the mother during KMC i.e., axilla, chest and abdomen was swabbed at the end of first week of life, prior to initiation of KMC. The 2nd swab involving the same areas was taken following KMC for 7 d for at least 6 h a day. The swabs were analysed using Next Generation Sequencing (NGS) - 16sRNA and abundance of organisms isolated were mapped. Statistical analyses using t-test and PERMANOVA were performed to compare phyla and genera of bacterial abundance pre-KMC and post-KMC.

RESULTS

KMC at phyla level increased the relative abundance of Firmicutes (p=0.52) and significantly decreased Proteobacteria (p=0.02). At species level, KMC decreased pathogenic bacterial count of Escherichia (p=0.05), while counts of S. hemolyticus (p=0.01) and S. hominis (p=.002) significantly increased post KMC.

CONCLUSIONS

KMC has a potential role in altering the neonatal skin microbiota towards a more favourable microenvironment. The clinical significance of these novel findings needs to be validated with larger studies.

Cohort profile: the BABY1000 pilot prospective longitudinal birth cohort study based in Sydney, Australia

PURPOSE

The health of parents prior to conception, a woman's health during pregnancy and the infant's environment across their first months and years collectively have profound effects on the child's health across the lifespan. Since there are very few cohort studies in early pregnancy, gaps remain in our understanding of the mechanisms underpinning these relationships, and how health may be optimised. 'BABY1000', a pilot prospective longitudinal birth cohort study, aims to (1) identify factors before and during pregnancy and early life that impact longer-term health and (2) assess the feasibility and acceptability of study design to inform future research.

PARTICIPANTS

Participants were based in Sydney, Australia. Women were recruited at preconception or 12 weeks' gestation, and data were collected from them throughout pregnancy and postpartum, their children until the age of 2 years, and dietary information from a partner (if able) at the last study visit. The pilot aimed to recruit 250 women. However, recruitment ceased earlier than planned secondary to limitations from the COVID-19 pandemic and the final number of subjects was 225.

FINDINGS TO DATE

Biosamples, clinical measurements and sociodemographic/psychosocial measures were collected using validated tools and questionnaires. Data analysis and 24-month follow-up assessments for children are ongoing. Key early findings presented include participant demographics and dietary adequacy during pregnancy. The COVID-19 pandemic and associated public health and research restrictions affected recruitment of participants, follow-up assessments and data completeness.

FUTURE PLANS

The BABY1000 study will provide further insight into the developmental origins of health and disease and inform design and implementation of future cohort and intervention studies in the field. Since the BABY1000 pilot was conducted across the COVID-19 pandemic, it also provides unique insight into the early impacts of the pandemic on families, which may have effects on health across the lifespan.

Vaginal and neonatal microbiota in pregnant women with preterm premature rupture of membranes and consecutive early onset neonatal sepsis

BACKGROUND

Preterm premature rupture of membranes (PPROM), which is associated with vaginal dysbiosis, is responsible for up to one-third of all preterm births. Consecutive ascending colonization, infection, and inflammation may lead to relevant neonatal morbidity including early-onset neonatal sepsis (EONS). The present study aims to assess the vaginal microbial composition of PPROM patients and its development under standard antibiotic therapy and to evaluate the usefulness of the vaginal microbiota for the prediction of EONS. It moreover aims to decipher neonatal microbiota at birth as possible mirror of the in utero microbiota.

METHODS

As part of the PEONS prospective multicenter cohort study, 78 women with PPROM and their 89 neonates were recruited. Maternal vaginal and neonatal pharyngeal, rectal, umbilical cord blood, and meconium microbiota were analyzed by 16S rRNA gene sequencing. Significant differences between the sample groups were evaluated using permutational multivariate analysis of variance and differently distributed taxa by the Mann-Whitney test. Potential biomarkers for the prediction of EONS were analyzed using the MetaboAnalyst platform.

RESULTS

Vaginal microbiota at admission after PPROM were dominated by Lactobacillus spp. Standard antibiotic treatment triggers significant changes in microbial community (relative depletion of Lactobacillus spp. and relative enrichment of Ureaplasma parvum) accompanied by an increase in bacterial diversity, evenness and richness. The neonatal microbiota showed a heterogeneous microbial composition where meconium samples were characterized by specific taxa enriched in this niche. The vaginal microbiota at birth was shown to have the potential to predict EONS with Escherichia/Shigella and Facklamia as risk taxa and Anaerococcus obesiensis and Campylobacter ureolyticus as protective taxa. EONS cases could also be predicted at a reasonable rate from neonatal meconium communities with the protective taxa Bifidobacterium longum, Agathobacter rectale, and S. epidermidis as features.

CONCLUSIONS

Vaginal and neonatal microbiota analysis by 16S rRNA gene sequencing after PPROM may form the basis of individualized risk assessment for consecutive EONS. Further studies on extended cohorts are necessary to evaluate how far this technique may in future close a diagnostic gap to optimize and personalize the clinical management of PPROM patients.

TRIAL REGISTRATION

NCT03819192, ClinicalTrials.gov. Registered on January 28, 2019.

Nonsurgical periodontal treatment during pregnancy and rates of preterm birth

BACKGROUND

Periodontitis during pregnancy is associated with an increased risk of preterm birth (<37 weeks of gestation) or low birthweight (<2500 g) offspring. Beyond periodontal disease, the risk of preterm birth varies both by previous history of preterm birth and in association with social determinants prevalent among vulnerable and marginalized populations. This study hypothesized that the timing of periodontal treatment during pregnancy and/or social vulnerability measures modified the response to dental scaling and root planing for the treatment of periodontitis and prevention of preterm birth.

OBJECTIVE

This study aimed to determine the association of timing of dental scaling and root planing for gravidae with a diagnosed periodontal disease on the rates of preterm birth or low birthweight offspring among subgroups or strata of gravidae as part of the Maternal Oral Therapy to Reduce Obstetric Risk randomized controlled trial. All participants in the study had clinically diagnosed periodontal disease and differed by the timing of the periodontal treatment (dental scaling and root planing at <24 weeks [per protocol] or after delivery) or by baseline characteristics. Although all participants met the well-accepted clinical criteria for periodontitis, not all participants acknowledged a priori that they had periodontal disease.

STUDY DESIGN

This was a per-protocol analysis of data from 1455 participants of the Maternal Oral Therapy to Reduce Obstetric Risk trial evaluating dental scaling and root planing on the risk of preterm birth or low birthweight offspring. Adjusted multiple logistic regression to control for confounders was used to estimate associations comparing the timing of periodontal treatment in pregnancy to receiving treatment after pregnancy (referent control) on rates of preterm birth or low birthweight among subgroups of gravidae with known periodontal disease. Study analyses were stratified, and the associations with the following characteristics-body mass index, self-described race and ethnicity, household income, maternal education, recency of immigration, and self-acknowledgment of poor oral health, were explored.

RESULTS

Dental scaling and root planing during the second or third trimester of pregnancy were associated with an increased adjusted odds ratio of preterm birth among those at the lower body mass index strata (18.5 to <25.0 kg/m²) (adjusted odds ratio, 2.21; 95% confidence interval, 1.07-4.98), but not among individuals who were overweight (body mass index of 25.0 to <30.0 kg/m²; adjusted odds ratio, 0.68; 95% confidence interval, 0.29-1.59) or obese (body mass index of ≥30 kg/m²; adjusted odds ratio, 1.26; 95% confidence interval, 0.65-2.49). There was no significant difference in pregnancy outcomes related to the other evaluated variables: self-described race and ethnicity, household income, maternal education, immigration status, or self-acknowledgment of poor oral health.

CONCLUSION

In this per-protocol analysis of the Maternal Oral Therapy to Reduce Obstetric Risk trial, dental scaling and root planing had no preventive benefit against adverse obstetrical outcomes and were associated with increased odds of preterm birth among individuals at lower body mass index strata. There was no significant difference in the occurrence of preterm birth or low birthweight after dental scaling and root planing periodontitis treatment concerning other analyzed social determinants of preterm birth.

Prenatal Maternal Antibiotics Treatment Alters the Gut Microbiota and Immune Function of Post-Weaned Prepubescent Offspring

This study aimed to investigate the immediate and continual perturbation to the gut microbiota of offspring in the weeks post-weaning and how these may be modulated by treating pregnant C57BL/6J dams with antibiotics (ABX). We used a broad-spectrum antibiotic cocktail consisting of ampicillin 1 mg/mL, neomycin 1 mg/mL, and vancomycin 0.5 mg/mL, or vancomycin 0.5 mg/mL alone, administered ad-lib orally to dams via drinking water during gestation and stopped after delivery. We analyzed the gut microbiota of offspring, cytokine profiles in circulation, and the brain to determine if there was evidence of a gut-immune-brain connection. Computationally predicted metabolic pathways were calculated from 16s rRNA sequencing data. ABX treatment can negatively affect the gut microbiota, including reduced diversity, altered metabolic activity, and immune function. We show that the maternal ABX-treatment continues to alter the offspring's gut microbiota diversity, composition, and metabolic pathways after weaning, with the most significant differences evident in 5-week-olds as opposed to 4-week-olds. Lower levels of chemokines and inflammatory cytokines, such as interleukin (IL)-1α and IL-2, are also seen in the periphery and brains of offspring, respectively. In conclusion, this study shows maternal antibiotic administration alters gut microbiome profiles in offspring, which undergoes a continuous transformation, from week to week, at an early age after weaning.

Vaginales Mikrobiom und Frühgeburtlichkeit

Hintergrund

Die Rate an Frühgeburten steigt weltweit an, ein bekannter Risikofaktor sind vaginale Infektionen.

Fragestellung

Welche Rolle spielen Infektionen als Ursache für Frühgeburtsbestrebungen? Wie ist das vaginale Mikrobiom in der Schwangerschaft zusammengesetzt und welche Bedeutung hat es in der Erkennung und Behandlung von Frühgeburtsbestrebungen.

Material und Methoden

Literaturrecherche in PubMed zu Infektion und Frühgeburten, frühem vorzeitigem Blasensprung und vaginalem Mikrobiom.

Ergebnisse

Die bakterielle Vaginose, eine Verminderung von Lactobacillus spp. und eine hohe Diversität von Bakterienstämmen im vaginalen Mikrobiom sind mit einem erhöhten Frühgeburtsrisiko assoziiert. Die antibiotische Therapie der bakteriellen Vaginose bei symptomatischen Schwangeren senkt das Frühgeburtsrisiko. Ein Screening asymptomatischer Schwangerer mit dem Ziel der Prävention von Frühgeburten ist derzeit nicht empfohlen. Das kindliche Mikrobiom und Immunsystem beginnt sich bereits in utero zu entwickeln, wobei Ernährung und Antibiotikaeinnahme während der Schwangerschaft eine wichtige Rolle spielen.

Schlussfolgerungen

Das vaginale Mikrobiom beeinflusst den Schwangerschaftsverlauf. Zwischen gesundem Mikrobiom und vaginaler Dysbiose kann klinisch nicht immer unterschieden werden. Mikrobiomanalysen leisten einen Beitrag zum besseren Verständnis pathologischer Veränderungen, jedoch gibt es aufgrund individueller Unterschiede keine allgemeine Definition des „gesunden Mikrobioms“.

Maternal antibiotics disrupt microbiome, behavior, and temperature regulation in unexposed infant mice

Maternal antibiotic (ABx) exposure can significantly perturb the transfer of microbiota from mother to offspring, resulting in dysbiosis of potential relevance to neurodevelopmental disorders such as autism spectrum disorder (ASD). Studies in rodent models have found long-term neurobehavioral effects in offspring of ABx-treated dams, but ASD-relevant behavior during the early preweaning period has thus far been neglected. Here, we exposed C57BL/6J mouse dams to ABx (5 mg/ml neomycin, 1.25 μg/ml pimaricin, .075% v/v acetic acid) dissolved in drinking water from gestational day 12 through offspring postnatal day 14. A number of ASD-relevant behaviors were assayed in offspring, including ultrasonic vocalization (USV) production during maternal separation, group huddling in response to cold challenge, and olfactory-guided home orientation. In addition, we obtained measures of thermoregulatory competence in pups during and following behavioral testing. We found a number of behavioral differences in offspring of ABx-treated dams (e.g., modulation of USVs by pup weight, activity while huddling) and provide evidence that some of these behavioral effects can be related to thermoregulatory deficiencies, particularly at younger ages. Our results suggest not only that ABx can disrupt microbiomes, thermoregulation, and behavior, but that metabolic effects may confound the interpretation of behavioral differences observed after early-life ABx exposure.

Neonatal intermittent hypoxia, fish oil, and/or antioxidant supplementation on gut microbiota in neonatal rats

BACKGROUND

Preterm infants frequently experience intermittent hypoxia (IH) episodes, rendering them susceptible to oxidative stress and gut dysbiosis. We tested the hypothesis that early supplementation with antioxidants and/or fish oil promotes gut biodiversity and mitigates IH-induced gut injury.

METHODS

Newborn rats were exposed to neonatal IH from birth (P0) to P14 during which they received daily oral supplementation with: (1) coenzyme Q10 (CoQ10) in olive oil, (2) fish oil, (3) glutathione nanoparticles (nGSH), (4) CoQ10 + fish oil, or (5) olive oil (placebo control). Pups were placed in room air (RA) from P14 to P21 with no further treatment. RA controls were similarly treated. Stool samples were assessed for microbiota and terminal ileum for histopathology and morphometry, total antioxidant capacity, lipid peroxidation, and biomarkers of gut injury.

RESULTS

Neonatal IH induced histopathologic changes consistent with necrotizing enterocolitis, which were associated with increased lipid peroxidation, toll-like receptor, transforming growth factor, and nuclear factor kappa B. Combination of CoQ10 + fish oil and nGSH were most effective for preserving gut integrity, reducing biomarkers of gut injury, and increasing commensal organisms.

CONCLUSIONS

Combination of antioxidants and fish oil may confer synergistic benefits to mitigate IH-induced injury in the terminal ileum.

IMPACT

Antioxidant and fish oil (PUFA) co-treatment was most beneficial for reducing neonatal IH-induced gut injury. The synergistic effects of antioxidant and fish oil is likely due to prevention of IH-induced ROS attack on lipids, thus preserving and augmenting its therapeutic benefits. Combination treatment was also effective for increasing the abundance of the non-pathogenic Firmicutes phylum, which is associated with a healthy gastrointestinal system of the newborn. Extremely low gestational age neonates who are at high risk for frequent, repetitive neonatal IH and oxidative stress-induced diseases may benefit from this combination therapy.

Maternal antibiotics exposure during pregnancy and the risk of acute lymphoblastic leukemia in childhood: a systematic review and meta-analysis

Many epidemiological studies have assessed the association between maternal antibiotic exposure during pregnancy and childhood acute lymphoblastic leukemia (ALL), while reaching inconsistent conclusions. In order to clarify the association, the publications in English that provided information about maternal antibiotic exposure during pregnancy and ALL risk in offspring in the PubMed, Embase, and Web of Science databases were systematically reviewed and we performed a meta-analysis using the random-effect models. Results of pooled analysis showed that maternal antibiotic intake during pregnancy is not associated with childhood ALL risk (pooled odds ratio 1.07, 95% confidence interval 0.98-1.18) without significant heterogeneity (I² = 13.7%, P = 0.310). This finding was consistent across subgroups stratified by type of study design, measurement method, sample size, study quality, and pregnancy stage. Our findings suggest that maternal antibiotic consumption during pregnancy was not associated with ALL risk in progeny. Further investigations are needed to confirm the results and assess any risk differences of ALL by types of antibiotics.Conclusions: Our findings suggest that maternal antibiotics consumption during pregnancy was not associated with ALL risk in progeny. Further investigations are needed to confirm the results and assess any risk differences of ALL by types of antibiotics. What is Known: • It is not unusual for pregnant woman to receive antibiotics for local or systematic use during pregnancy. • The conclusions regarding the associations between maternal antibiotics use during pregnancy and childhood ALL risk were inconsistent. What is New: • Maternal antibiotics consumption during pregnancy was not associated with the increased ALL risk in offspring. • Further laboratory evidences are needed to confirm the results.

The Relationship Between Maternal and Neonatal Microbiota in Spontaneous Preterm Birth: A Pilot Study

The newborn's microbiota composition at birth seems to be influenced by maternal microbiota. Maternal vaginal microbiota can be a determining factor of spontaneous Preterm Birth (SP^PTB), the leading cause of perinatal mortality. The aim of the study is to investigate the likelihood of a causal relationship between the maternal vaginal microbiota composition and neonatal lung and intestinal microbiota profile at birth, in cases of SP^PTB. The association between the lung and/or meconium microbiota with the subsequent development of bronchopulmonary dysplasia (BPD) was also investigated. Maternal vaginal swabs, newborns' bronchoalveolar lavage fluid (BALF) (1st, 3rd, 7th day of life) and first meconium samples were collected from 20 women and 23 preterm newborns with gestational age ≤ 30 weeks (12 = SP^PTB; 11 = Medically Indicated Preterm Birth-MI^PTB). All the samples were analyzed for culture examination and for microbiota profiling using metagenomic analysis based on the Next Generation Sequencing (NGS) technique of the bacterial 16S rRNA gene amplicons. No significant differences in alpha e beta diversity were found between the neonatal BALF samples of SP^PTB group and the MI^PTB group. The vaginal microbiota of mothers with SP^PTB showed a significant difference in alpha diversity with a decrease in Lactobacillus and an increase in Proteobacteria abundance. No association was found between BALF and meconium microbiota with the development of BPD. Vaginal colonization by Ureaplasma bacteria was associated with increased risk of both SP^PTB and newborns' BPD occurrence. In conclusion, an increase in α-diversity values and a consequent fall in Lactobacillus in vaginal environment could be associated to a higher risk of SP^PTB. We could identify neither a specific neonatal lung or meconium microbiota profiles in preterm infants born by SP^PTB nor a microbiota at birth suggestive of subsequent BPD development. Although a strict match has not been revealed between microbiota of SP^PTB mother-infant couples, a relationship cannot be excluded. To figure out the reciprocal influence of the maternal-neonatal microbiota and its potential role in the pathogenesis of SP^PTB and BPD further research is needed.

Maternal exposures and the infant gut microbiome: a systematic review with meta-analysis

Early life, including the establishment of the intestinal microbiome, represents a critical window of growth and development. Postnatal factors affecting the microbiome, including mode of delivery, feeding type, and antibiotic exposure have been widely investigated, but questions remain regarding the influence of exposures in utero on infant gut microbiome assembly. This systematic review aimed to synthesize evidence on exposures before birth, which affect the early intestinal microbiome. Five databases were searched in August 2019 for studies exploring pre-pregnancy or pregnancy 'exposure' data in relation to the infant microbiome. Of 1,441 publications identified, 76 were included. Factors reported influencing microbiome composition and diversity included maternal antibiotic and probiotic uses, dietary intake, pre-pregnancy body mass index (BMI), gestational weight gain (GWG), diabetes, mood, and others. Eleven studies contributed to three meta-analyses quantifying associations between maternal intrapartum antibiotic exposure (IAP), BMI and GWG, and infant microbiome alpha diversity (Shannon Index). IAP, maternal overweight/obesity and excessive GWG were all associated with reduced diversity. Most studies were observational, few included early recruitment or longitudinal follow-up, and the timing, frequency, and methodologies related to stool sampling and analysis were variable. Standardization and collaboration are imperative to enhance understanding in this complex and rapidly evolving area.

Early life gut microbiota is associated with rapid infant growth in Hispanics from Southern California

We aimed to determine if the newborn gut microbiota is an underlying determinant of early life growth trajectories. 132 Hispanic infants were recruited at 1-month postpartum. The infant gut microbiome was characterized using 16S rRNA amplicon sequencing. Rapid infant growth was defined as a weight-for-age z-score (WAZ) change greater than 0.67 between birth and 12-months of age. Measures of infant growth included change in WAZ, weight-for-length z-score (WLZ), and body mass index (BMI) z-scores from birth to 12-months and infant anthropometrics at 12-months (weight, skinfold thickness). Of the 132 infants, 40% had rapid growth in the first year of life. Multiple metrics of alpha-diversity predicted rapid infant growth, including a higher Shannon diversity (OR = 1.83; 95% CI: 1.07-3.29; p = .03), Faith's phylogenic diversity (OR = 1.41, 95% CI: 1.05-1.94; p = .03), and richness (OR = 1.04, 95% CI: 1.01-1.08; p = .02). Many of these alpha-diversity metrics were also positively associated with increases in WAZ, WLZ, and BMI z-scores from birth to 12-months (pall<0.05). Importantly, we identified subsets of microbial consortia whose abundance were correlated with these same measures of infant growth. We also found that rapid growers were enriched in multiple taxa belonging to genera such as Acinetobacter, Collinsella, Enterococcus, Neisseria, and Parabacteroides. Moreover, measures of the newborn gut microbiota explained up to an additional 5% of the variance in rapid growth beyond known clinical predictors (R2 = 0.37 vs. 0.32, p < .01). These findings indicate that a more mature gut microbiota, characterized by increased alpha-diversity, at as early as 1-month of age, may influence infant growth trajectories in the first year of life.

No Worm Is an Island; The Influence of Commensal Gut Microbiota on Cyathostomin Infections

Simple Summary

There is increasing evidence for the importance of gut bacteria in animal health and disease. This is particularly relevant for gastrointestinal infections, such as parasitic worms, which share a niche with gut bacteria. Parasitic worms are highly prevalent in domestic horses and are a significant cause of disease in this population. This commentary explores the complex relationships between the most common parasitic worm in horses (cyathostomins) and gut bacteria, based on recent studies in horses and other species. We propose novel theories and avenues for research that harness these relationships and have the potential to improve control of parasitic worms, and overall equine health, in the future.

Abstract

The importance of the gut microbiome for host health has been the subject of intense research over the last decade. In particular, there is overwhelming evidence for the influence of resident microbiota on gut mucosal and systemic immunity; with significant implications for the outcome of gastrointestinal (GI) infections, such as parasitic helminths. The horse is a species that relies heavily on its gut microbiota for GI and overall health, and disturbances in this complex ecosystem are often associated with life-threatening disease. In turn, nearly all horses harbour parasitic helminths from a young age, the most prevalent of which are the small strongyles, or cyathostomins. Research describing the relationship between gut microbiota and cyathostomin infection is in its infancy, however, to date there is evidence of meaningful interactions between these two groups of organisms which not only influence the outcome of cyathostomin infection but have long term consequences for equine host health. Here, we describe these interactions alongside supportive evidence from other species and suggest novel theories and avenues for research which have the potential to revolutionize our approach to cyathostomin prevention and control in the future.

The Infant Gut Microbiota and Risk of Asthma: The Effect of Maternal Nutrition during Pregnancy and Lactation

Research has amply demonstrated that early life dysbiosis of the gut microbiota influences the propensity to develop asthma. The influence of maternal nutrition on infant gut microbiota is therefore of growing interest. However, a handful of prospective studies have examined the role of maternal dietary patterns during pregnancy in influencing the infant gut microbiota but did not assess whether this resulted in an increased risk of asthma later in life. The mechanisms involved in the process are also, thus far, poorly documented. There have also been few studies examining the effect of maternal dietary nutrient intake during lactation on the milk microbiota, the effect on the infant gut microbiota and, furthermore, the consequences for asthma development remain largely unknown. Therefore, the specific aim of this mini review is summarizing the current knowledge regarding the effect of maternal nutrition during pregnancy and lactation on the infant gut microbiota composition, and whether it has implications for asthma development.

Contributors to Dysbiosis in Very-Low-Birth-Weight Infants

The objective of this commentary was to analyze the causes and outcomes of gut microbiome dysbiosis in preterm infants who are born at very low birth weight (VLBW). The intrauterine development of VLBW infants is interrupted abruptly with preterm birth and followed by extrauterine, health-threatening conditions and sequelae. These infants develop intestinal microbial dysbiosis characterized by low diversity, an overall reduction in beneficial and/or commensal bacteria, and enrichment of opportunistic pathogens of the Gammaproteobacteria class. The origin of VLBW infant dysbiosis is not well understood and is likely the result of a combination of immaturity and medical care. We propose that these factors interact to produce inflammation in the gut, which further perpetuates dysbiosis. Understanding the sources of dysbiosis could result in interventions to reduce gut inflammation, decrease enteric pathology, and improve health outcomes for these vulnerable infants.

Preterm neonatal immunology at the intestinal interface

Fetal and neonatal development represents a critical window for setting a path toward health throughout life. In this review, we focus on intestinal immunity, how it develops, and its implications for subsequent neonatal diseases. We discuss maternal nutritional and environmental exposures that dictate outcomes for the developing fetus. Although still controversial, there is evidence in support of an in utero microbiome. Specific well-intentioned and routine applications of antibiotics, steroids, and surgical interventions implemented before, during, and after birth skew the neonate towards pro-inflammatory dysbiosis. Shortly after birth, a consortium of maternal and environmentally derived bacteria, through cross-talk with the developing host immune system, takes center stage in developing or disrupting immune homeostasis at the intestinal interface. We also examine subsequent immunological cross-talks, which involve neonatal myeloid and lymphoid responses, and their potential impacts on health and disease such as necrotizing enterocolitis and sepsis, especially critical disease entities for the infant born preterm.

Colonization profile and duration by multi-resistant organisms in a prospective cohort of newborns after hospital discharge

The aim of this study was to determine the spontaneous decolonization period and characteristics in a prospective cohort of newborns colonized by multidrug-resistant organisms, after their discharge from the neonatal intensive care unit. Multidrug resistance is defined as bacterial non-susceptibility to ≥ 1 agent of ≥ 3 antimicrobial categories. In total, 618 newborns were included in the study, of which 173 (28.0%) presented a positive culture for multidrug-resistant microorganisms, and of these, 52 (30.1%) were followed up in this study. The most frequent intrinsic factors were be born by cesarean section (86.5%), prematurity (84.6%), and very low birth weight (76.9%). The extrinsic factors were having remained hospitalized for an average of 27 days, during which 67.3% were submitted to invasive procedures and 88.5% received antimicrobials. The intrinsic and extrinsic factors of newborns were not associated to a decolonization period longer or shorter than 3 months, which was the average period of decolonization found in the present study. From the totality of colonization cultures sampled at hospital discharge, the Gram-negative Extended Spectrum β-lactamase producing bacteria were the most common, with 28.9% of babies colonized by Klebsiella spp. The median period of decolonization by multidrug-resistant microorganisms in the newborns population after hospital discharge was 3 months, but was highly dependent on the microbial species, and this period was not associated to any intrinsic and extrinsic factors of the newborn.

Neonatal Microbiome and Its Relationship to Necrotizing Enterocolitis: A Review of the Science

Necrotizing enterocolitis (NEC) occurs in many premature infants hospitalized in the neonatal intensive care unit. About 3% to 15% of very low-weight premature infants develop NEC, with an estimated 30% mortality rate for the cases requiring surgery. Currently, there is no known pathogenesis for NEC in the patient's populations. However, one of the most widely accepted hypotheses is having an abnormal fetal gut microbiome. The purpose of this review is to discuss some current methods of dysbiosis in the neonatal microbiome, such as maternal health, breastfeeding, and delivery method, and then to connect these to the occurrence of NEC in the infant and finally discuss some possibilities for limiting the occurrence of NEC in the future.

Is the Newborn Microbiome Disrupted by Routine Newborn Suctioning? An Exploratory Approach for Policy Development

An invasive procedure commonly used in the perinatal setting is newborn suctioning at birth. Routine newborn suctioning, without indication, is not recommended by the American Academy of Pediatrics, the American Heart Association, and the European Resuscitation Council for the newborn with spontaneous respirations, adequate crying, and good muscle tone. Whether to suction a newborn is a difficult practice decision made daily by the perinatal nurse. A primary element of this practice decision is the consideration that newborn suctioning has the potential to affect health outcomes. Furthermore, routine newborn suctioning may be disrupting the newborn microbiome by removing commensal bacteria and potentially, negatively affecting newborn health. This article will explore the connection between the practice of routine newborn suctioning in the perinatal setting and the potential to disrupt the newborn microbiome. The methods employed and reported in this article consisted of review of literature and review of clinical guidelines and a descriptive study to determine the scope of practice of newborn suctioning. The premise of whether the practice of routine newborn suctioning at birth may be disrupting the newborn microbiome will also be considered. Finally, developing a microbiome-centric perspective will be explored.

Laboratory Analysis Techniques for the Perinatal Microbiome: Implications for Studies of Probiotic Interventions

The microbiome is composed of many organisms and is impacted by an intricate exchange between genetics and environmental factors. The perinatal microbiome influences both the developing fetus and the pregnant person. The purpose of this article is to describe the tests that are currently available for laboratory analysis of the perinatal microbiome in relationship to probiotic interventions. This article focuses on the bacterial component of the microbiome. Although adverse outcomes associated with the perinatal microbiome have been studied, a comprehensive understanding of the physiologic perinatal microbiome is still emerging. Early efforts to influence the perinatal microbiome through probiotics are currently under investigation. Unique terminology is defined, and the microbial composition of perinatal microbiota is summarized. The outcomes of studies of antenatal probiotics are summarized. Microbiome testing and analysis are defined and compared. Implications for perinatal care and probiotics research are presented.

Dysbiosis associated with acute helminth infections in herbivorous youngstock - observations and implications

A plethora of data points towards a role of the gastrointestinal (GI) microbiota of neonatal and young vertebrates in supporting the development and regulation of the host immune system. However, knowledge of the impact that infections by GI helminths exert on the developing microbiota of juvenile hosts is, thus far, limited. This study investigates, for the first time, the associations between acute infections by GI helminths and the faecal microbial and metabolic profiles of a cohort of equine youngstock, prior to and following treatment with parasiticides (ivermectin). We observed that high versus low parasite burdens (measured via parasite egg counts in faecal samples) were associated with specific compositional alterations of the developing microbiome; in particular, the faecal microbiota of animals with heavy worm infection burdens was characterised by lower microbial richness, and alterations to the relative abundances of bacterial taxa with immune-modulatory functions. Amino acids and glucose were increased in faecal samples from the same cohort, which indicated the likely occurrence of intestinal malabsorption. These data support the hypothesis that GI helminth infections in young livestock are associated with significant alterations to the GI microbiota, which may impact on both metabolism and development of acquired immunity. This knowledge will direct future studies aimed to identify the long-term impact of infection-induced alterations of the GI microbiota in young livestock.

Neonatal microbiome - a brief review

The long-held concept of fetus being nurtured in a sterile environment has been challenged by many recent studies that have identified bacterial communities in meconium, amniotic fluid and the placenta concluding that the microbial colonization of fetal gut begins in utero and continues during the first 2 years of life. This microbial colonization of newborn's gut during prenatal, intrapartum, and postnatal period depends on multiple factors, e.g. maternal diet, stress, antibiotic exposure, mode of delivery, type of feeding (human milk versus formula), etc., and imparts a critical role in the development of gastrointestinal, immunological, and neural systems in newborns. This article briefly reviews the current state of knowledge of microbiome in the maternal fetal unit and its impact on subsequent neonatal health and diseases.

The Human Microbiome and Gender Medicine

Discoveries in molecular genetics over the last two decades have broadened our information about the genomics of complex microbial communities. As in all other fields of medicine, there is an undeniable need to explore the microbiome and the way it is impacted by biological sex. A number, although small, of recent studies have demonstrated that women and men have striking differences in the species that constitute their microbiomes. This effects pathological physiology in fields such as hepatology, oncology, autoimmune disease (most notably diabetes mellitus), autism, and obstetrics. There is still an unfortunate lack of research being done on the “microgenderome”: the interaction between microbiota, sex hormones, and the immune system. This review will highlight some of the main areas to be affected by microgenderome physiology, with an in depth focus on obstetrics.