Meconium microbiota types dominated by lactic acid or enteric bacteria are differentially associated with maternal eczema and respiratory problems in infants

Is domestic violence during COVID-19 in lactating women related to infantile colic? An important question

BACKGROUND

Psychosocial factors such as maternal stress in lactating women were shown to be related to an increased risk of infantile colic because the infants can be affected through breast milk. Therefore, domestic violence against lactating mothers can be effective on the infants' health. It is also demonstrated that domestic violence against women has increased following the COVID-19 pandemic and quarantine. Therefore, this study aims to assess the relationship between domestic violence against breastfeeding women during COVID-19 and the incidence of infantile colic.

METHODS

This was a case-control study that was conducted on 356 lactating mothers who attended Bentolhoda Hospital in Bojnoord-Iran from November 2021 to August 2022. The participants were exclusively breastfeeding mothers who were under 6 months infants. Mothers with and without infantile colic infants were considered the case and control groups, respectively. Two questionnaires were used for data collection including a demographic questionnaire, and a questionnaire to assess domestic violence against women during the quarantine period of Corona pandemic. The data was analyzed using SPSS-V22 and Pearson Spearman correlation and linear regression tests.

RESULTS

The results showed that women in the case group had a significantly higher score for "sexual violence and restraint" than women in the control group [0.59 ± 0.34 versus 0.62 ± 0.25 (Mean ± SD), respectively] (P < 0.05). The chance of infantile colic was higher among the infants of mothers who experienced domestic violence, but it was not statistically significant (OR = 1.236, P = 0.573). Significant relationships were found between the infantile colic and the history of abortion (OR = 1.430, P = 0.028) and cesarean section (OR = 1.723, P = 0.044).

CONCLUSION

Domestic violence during pregnancy can potentially increase infant colic through breast milk. Although our findings need more investigation, it can be recommended to plan the direction of screening for domestic violence and providing the necessary care and counseling to the parents in perinatal care services to prevent infantile colic and improve the infant's health.

The association of infant and mother gut microbiomes with development of allergic diseases in children: a systematic review

OBJECTIVE

It is believed that gut microbiota alteration leads to both intestinal and non-intestinal diseases in children. Since infants inherit maternal microbiota during pregnancy and lactation, recent studies suggest that changes in maternal microbiota can cause immune disorders as well. This systematic review was designed to assess the association between the child and mother's gut microbiome and allergy development in childhood.

DATA SOURCES

In this systematic review, international databases including PubMed, Scopus, and ISI/WOS were searched until January 2023 to identify relevant studies.

STUDY SELECTIONS

Observational studies that analyzed infant or maternal stool microbiome and their association with allergy development in children were included in this study. Data extraction and quality assessment of the included studies were independently conducted by two researchers.

RESULTS

Of the 1694 papers evaluated, 21 studies examined neonate gut microbiome by analyzing stool samples and six studies examined maternal gut microbiota. A total of 5319 participants were included in this study. Asthma followed by eczema and dermatitis were the most common allergy disorders among children. Urbanization caused a lack of diversity in the bacterial microbiota as well as lower levels of Bifidobacterium and Lachnospira associated with a higher risk of allergy. In contrast, higher levels of Roseburia and Flavonifractor were associated with lower allergy risk.

CONCLUSIONS

This systematic review shows that gut microbiota may be associated with allergy development. Further studies are required to provide a definitive answer.

Perinatal Exposure to Tobacco Smoke and Its Association with the Maternal and Offspring Microbiome: A Systematic Review

BACKGROUND

The human microbiome, comprising trillions of microorganisms, significantly influences human health and disease. During critical periods like the perinatal phase, the microbiome undergoes significant changes, impacting lifelong health. Tobacco smoke, a known environmental pollutant, has adverse effects on health, particularly during pregnancy. Despite this, its association with the perinatal microbiome remains understudied.

METHODS

We conducted a systematic review to integrate findings on perinatal tobacco smoke exposure and its association with the maternal and neonatal microbiomes. We conducted a comprehensive literature search in the PubMed, Scopus, and Web of Science databases from January 2000 to February 2024. We selected studies that met predefined inclusion criteria and performed data extraction.

RESULTS

The review included eight studies that revealed diverse associations of perinatal tobacco exposure with the maternal and neonatal microbiome. Active smoking during pregnancy was linked to alterations in microbiome composition and diversity in children. Maternal smoking correlated with increased Firmicutes abundance and decreased Akkermansia muciniphila abundance in offspring. Additionally, exposure to thirdhand smoke in neonatal intensive care units was related to infant microbiome diversity. Infants exposed to tobacco smoke showed various microbial changes, suggesting potential implications for childhood health outcomes, including obesity risk.

CONCLUSIONS

Perinatal exposure to tobacco smoke exerts significant influence on the maternal and neonatal microbiomes, with potential implications for long-term health outcomes. Addressing socioeconomic and psychological barriers to smoking cessation, implementing stricter smoking regulations, and promoting public health campaigns are essential steps towards reducing tobacco-related harm during the perinatal period. Further longitudinal studies and standardized assessment methods are needed to validate these findings and guide the development of effective preventive measures.

Intrauterine Shaping of Fetal Microbiota

Mechanisms resulting from the physiological immaturity of the digestive system in children delivered before 32 weeks of gestation and, in particular, different interactions between the microbiome and the body have not been fully elucidated yet. Next-generation sequencing methods demonstrated the presence of bacterial DNA in the placenta and amniotic fluid, which may reflect bacterial populations that initiate intestinal colonization in utero. Numerous studies confirmed the hypothesis stating that intestinal bacteria played an important role in the pathogenesis of necrotizing enterocolitis (NEC) early- and late-onset neonatal sepsis (EONS and LONS). The model and scale of disorders within the intestinal microbiome are the subject of active research in premature infants. Neonatal meconium was primarily used as an indicator defining the environment in utero, as it is formed before birth. Metagenomic results and previous data from microbiological bacterial cultures showed a correlation between the time from birth to sample collection and the detection of bacteria in the neonatal meconium. Therefore, it may be determined that the colonization of the newborn's intestines is influenced by numerous factors, which may be divided into prenatal, perinatal, and postnatal, with particular emphasis put on the mode of delivery and contact with the parent immediately after birth. Background: The aim of this review was to collect available data on the intrauterine shaping of the fetal microbiota. Methods: On 13 March 2024, the available literature in the PubMed National Library of Medicine search engine was reviewed using the following selected keywords: "placental microbiome", "intestinal bacteria in newborns and premature infants", and "intrauterine microbiota". Results: After reviewing the available articles and abstracts and an in-depth analysis of their content, over 100 articles were selected for detailed elaboration. We focused on the origin of microorganisms shaping the microbiota of newborns. We also described the types of bacteria that made up the intrauterine microbiota and the intestinal microbiota of newborns. Conclusions: The data presented in the review on the microbiome of both term newborns and those with a body weight below 1200 g indicate a possible intrauterine colonization of the fetus depending on the duration of pregnancy. The colonization occurs both via the vaginal and intestinal route (hematogenous route). However, there are differences in the demonstrated representatives of various types of bacteria, phyla Firmicutes and Actinobacteria in particular, taking account of the distribution in their abundance in the individual groups of pregnancy duration. Simultaneously, the distribution of the phyla Actinobacteria and Proteobacteria is consistent. Considering the duration of pregnancy, it may also be concluded that the bacterial flora of vaginal origin dominates in preterm newborns, while the flora of intestinal origin dominates in term newborns. This might explain the role of bacterial and infectious factors in inducing premature birth with the rupture of fetal membranes.

Arthropods to Eutherians: A Historical and Contemporary Comparison of Sparse Prenatal Microbial Communities Among Animalia Species

Since the advent of next-generation sequencing, investigators worldwide have sought to discern whether a functional and biologically or clinically relevant prenatal microbiome exists. One line of research has led to the hypothesis that microbial DNA detected in utero/in ovo or prior to birth/hatching is a result of contamination and does not belong to viable and functional microbes. Many of these preliminary evaluations have been conducted in humans, mice, and nonhuman primates due to sample and specimen availability. However, a comprehensive review of the literature across animal species suggests organisms that maintain an obligate relationship with microbes may act as better models for interrogating the selective pressures placed on vertical microbial transfer over traditional laboratory species. To date, studies in humans and viviparous laboratory species have failed to illustrate the clear presence and transfer of functional microbes in utero. Until a ground truth regarding the status and relevance of prenatal microbes can be ascertained, it is salient to conduct parallel investigations into the prevalence of a functional prenatal microbiome across the developmental lifespan of multiple organisms in the kingdom Animalia. This comprehensive understanding is necessary not only to determine the role of vertically transmitted microbes and their products in early human health but also to understand their full One Health impact. This review is among the first to compile such comprehensive primary conclusions from the original investigator's conclusions, and hence collectively illustrates that prenatal microbial transfer is supported by experimental evidence arising from over a long and rigorous scientific history encompassing a breadth of species from kingdom Animalia.

The infants' gut microbiome: setting the stage for the early onset of obesity

In the past three decades, dietary and lifestyle changes worldwide have resulted in a global increase in the prevalence of obesity in both adults and children. Known to be highly influenced by genetic, environmental and lifestyle factors, obesity is characterized by a low-grade chronic inflammation that contributes to the development of other metabolic diseases such as diabetes and cardiovascular disease. Recently, the gut microbiome has been added as a cause/contributor to the development of obesity. As differences in the microbiome between obese and normoweight individuals have been observed, we set out to determine whether infants harbor an obesogenic microbiome early on and whether the pre-pregnancy status of the mother (obese or normoweight) is correlated to their infant's microbiome composition. Using shotgun sequencing, we analyzed stool samples throughout the first year of life from infants born to obese (n = 23 participants, m = 104 samples) and normoweight (n = 23 participants, m = 99 samples) mothers. We found that the infants' microbiome diversity at taxonomic and functional levels was significantly influenced by time (ANOVA p < 0.001) but not by the mother's pre-pregnancy status. Overall, no deterministic succession of taxa or functions was observed. However, infants born to obese mothers were found to have a significantly higher Bacillota/Bacteroidota ratio (p = 0.02) at six months, were significantly depleted from six months old of the well-established obesity biomarkers Akkermansia municiphila and Faecalibacterium prausnitzii (p < 0.01), and were at one week old, significantly enriched in pathways such as the UDP-N-acetyl-D-glucosamine biosynthesis II (p = 0.02) involved in leptin production, suggesting perhaps that there may exist some underlying mechanisms that dictate the development of an obesogenic microbiota early on.

The Role of Gut Microbiome in Sleep Quality and Health: Dietary Strategies for Microbiota Support

Dietary components, including dietary fiber, unsaturated fatty acids, and polyphenols, along with meal timing and spacing, significantly affect the microbiota's capacity to produce various metabolites essential for quality sleep and overall health. This review explores the role of gut microbiota in regulating sleep through various metabolites such as short-chain fatty acids, tryptophan, serotonin, melatonin, and gamma-aminobutyric acid. A balanced diet rich in plant-based foods enhances the production of these sleep-regulating metabolites, potentially benefiting overall health. This review aims to investigate how dietary habits affect gut microbiota composition, the metabolites it produces, and the subsequent impact on sleep quality and related health conditions.

Personalized Nutrition with Banked Human Milk for Early Gut Microbiota Development: In Pursuit of the Perfect Match

The correct initial colonization and establishment of the gut microbiota during the early stages of life is a key step, with long-lasting consequences throughout the entire lifespan of the individual. This process is affected by several perinatal factors; among them, feeding mode is known to have a critical role. Breastfeeding is the optimal nutrition for neonates; however, it is not always possible, especially in cases of prematurity or early pathology. In such cases, most commonly babies are fed with infant formulas in spite of the official nutritional and health international organizations' recommendation on the use of donated human milk through milk banks for these cases. However, donated human milk still does not totally match maternal milk in terms of infant growth and gut microbiota development. The present review summarizes the practices of milk banks and hospitals regarding donated human milk, its safety and quality, and the health outcomes in infants fed with donated human milk. Additionally, we explore different alternatives to customize pasteurized donated human milk with the aim of finding the perfect match between each baby and banked milk for promoting the establishment of a beneficial gut microbiota from the early stages of life.

The Role of Biodiversity in the Development of Asthma and Allergic Sensitization: A State-of-the-Science Review

BACKGROUND

Changes in land use and climate change have been reported to reduce biodiversity of both the environment and human microbiota. These reductions in biodiversity may lead to inadequate and unbalanced stimulation of immunoregulatory circuits and, ultimately, to clinical diseases, such as asthma and allergies.

OBJECTIVE

We summarized available empirical evidence on the role of inner (gut, skin, and airways) and outer (air, soil, natural waters, plants, and animals) layers of biodiversity in the development of asthma, wheezing, and allergic sensitization.

METHODS

We conducted a systematic search in SciVerse Scopus, PubMed MEDLINE, and Web of Science up to 5 March 2024 to identify relevant human studies assessing the relationships between inner and outer layers of biodiversity and the risk of asthma, wheezing, or allergic sensitization. The protocol was registered in PROSPERO (CRD42022381725).

RESULTS

A total of 2,419 studies were screened and, after exclusions and a full-text review of 447 studies, 82 studies were included in the comprehensive, final review. Twenty-nine studies reported a protective effect of outer layer biodiversity in the development of asthma, wheezing, or allergic sensitization. There were also 16 studies suggesting an effect of outer layer biodiversity on increasing asthma, wheezing, or allergic sensitization. However, there was no clear evidence on the role of inner layer biodiversity in the development of asthma, wheezing, and allergic sensitization (13 studies reported a protective effect and 15 reported evidence of an increased risk).

CONCLUSIONS

Based on the reviewed literature, a future systematic review could focus more specifically on outer layer biodiversity and asthma. It is unlikely that association with inner layer biodiversity would have enough evidence for systematic review. Based on this comprehensive review, there is a need for population-based longitudinal studies to identify critical periods of exposure in the life course into adulthood and to better understand mechanisms linking environmental exposures and changes in microbiome composition, diversity, and/or function to development of asthma and allergic sensitization. https://doi.org/10.1289/EHP13948.

Composition of the microbiota in patients with growth hormone deficiency before and after treatment with growth hormone

INTRODUCTION

Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) have modulatory effects on bowel function and its microbiota. Our aim was to investigate whether low levels of GH and IGF-1 in patients with GH deficiency are associated with changes in gut physiology/integrity as well as in the composition of the gut microbiota.

MATERIALS AND METHODS

We conducted a case-control study in 21 patients with GH deficiency, at baseline and after 6 months of GH treatment, and in 20 healthy controls. We analysed changes in anthropometric and laboratory characteristics and bacterial translocation and studied the composition of the microbiome by means of massive 16S rRNA gene sequencing.

RESULTS

Growth hormone deficiency was accompanied by a significant increase in serum levels of sCD14, a marker of bacterial translocation (P < .01). This increase was reversed by GH treatment. We did not find any differences in the composition or α- or β-diversity of the gut microbiota after treatment or between cases and controls.

CONCLUSIONS

Our work is the first to demonstrate that the presence of GH deficiency is not associated with differences in gut microbiota composition in comparison with healthy controls, and changes in microbiota composition are also not found after 6 months of treatment. However, GH deficiency and low IGF-1 levels were associated with an increase in bacterial translocation, which had reversed after treatment.

Umbilical Cord Blood IgA Levels and Bacterial Profile in Preterm Neonates Born with Maternal Risk Factors for Early-Onset Neonatal Sepsis

OBJECTIVES

To investigate the IgA levels and bacterial profile in umbilical cord blood (UCB) samples of mothers with risk factors compared to those without risk factors; and to understand the link between UCB culture positivity and neonatal outcomes [early-onset sepsis (EOS) or death within 7 d of life].

METHODS

This is a pilot prospective case-control study. Mothers with preterm deliveries (gestational age <34 wk) were enrolled in two groups- Cases: Those with antenatal risk factors (prolonged duration of rupture of membranes of ≥24 h or chorioamnionitis) and controls: Those without these two risk factors. Serum IgA levels was assayed and microbiological culture was tested in UCB samples. 16S sequencing to determine the UCB microbiome was performed in a subset of samples (n = 15). Neonates were followed-up for the occurrence of EOS or death until 7 d of life.

RESULTS

Forty-nine mothers as cases and 50 mothers as controls were consecutively enrolled. No significant difference was observed in the IgA levels (60.5 vs. 58.1 mg/L; p = 0.71), neonatal blood culture positivity (4.1% vs. 8.0%; p = 0.41) and UCB culture positivity (30.6% vs. 26.0%; p = 0.61) in the two groups. No difference was observed between the groups in occurrence of EOS or death within 7 d of life. Proteobacteria, Firmicutes and Actinobacteria were the most abundant phyla. Serratia, Bifidobacterium, Collinsella, Meganomas and Blautia being the most common genera.

CONCLUSIONS

Cord blood IgA concentration could not differentiate the neonates at-risk of infection due to its presence in both the groups.

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.

Microbiota of pregnancy, placenta and newborns in the third trimester: A randomized controlled study

Microbiota in pregnant time is vital to healthy of pregnant women and their offspring. However, few study evaluate the composition of the microbiota of health pregnancy, placenta and their newborns at different stages and the origin of the placental microbiota. Samples were obtained from a total of 31 pregnant individuals and their offspring, analyzing by 16S rRNA amplicon sequencing of the V4 region to evaluate the composition and variation of them. We found that the microbiota of pregnant individuals changes in the third trimester. The placental microbiota has its own specific dominant microbiota. The placental microbiota is correlated with the pregnancy microbiota in the gut and vagina at 32-34 weeks but not at full term. The gut microbiota in newborns changes over the first 14 days.

Symbiotic Synergy from Sponges to Humans: Microflora-Host Harmony Is Crucial for Ensuring Survival and Shielding against Invading Pathogens

Gut microbiota plays several roles in the host organism's metabolism and physiology. This phenomenon holds across different species from different kingdoms and classes. Different species across various classes engage in continuous crosstalk via various mechanisms with their gut microbiota, ensuring homeostasis of the host. In this Review, the diversity of the microflora, the development of the microflora in the host, its regulations by the host, and its functional implications on the host, especially in the context of dysbiosis, are discussed across different organisms from sponges to humans. Overall, our review aims to address the indispensable nature of the microbiome in the host's survival, fitness, and protection against invading pathogens.

Associations of maternal prenatal psychological symptoms and saliva cortisol with neonatal meconium microbiota: A cross-sectional study

Alterations in the diversity and relative abundances of the gut microbiome have been associated with a broad spectrum of medical conditions. Maternal psychological symptoms during pregnancy may impact on offspring development by altering the maternal and the foetal gut microbiome. We aimed to investigate whether self-reported maternal anxiety, depressive symptoms, and distress as well as saliva cortisol levels in late pregnancy alter the bacterial composition of the infant's meconium.

METHODS

A total of N = 100 mother-infant pairs were included. Maternal psychological symptoms were measured using psychological questionnaires (EPDS, PSS-10, STAI) at 34-36 weeks gestation and salivary cortisol was measured at 34-36 and 38 weeks gestation. Infant meconium samples were collected in the first five days postpartum and analysed using 16S rRNA amplicon sequencing.

RESULTS

Correlations showed that lower alpha diversity of the meconium microbiome was significantly associated with increased maternal prenatal depressive symptoms in late gestation (τ = -0.15, p = .04). Increased saliva cortisol AUCg at T2 was significantly related to higher beta diversity of the meconium samples (Pr(>F) = 0.003*). Pseudomonas was the most abundant phylum and was associated with maternal saliva cortisol total decline. No other associations were found.

CONCLUSIONS

Maternal prenatal depressive symptoms are associated with infant faecal microbiome alpha diversity, whereas maternal saliva cortisol AUCg is linked to increased beta diversity and total decline related to increased Psuedomonas. Future studies are warranted to understand how these microbiota community alterations are linked to child health outcomes.

Shaping Microbiota During the First 1000 Days of Life

Given that the host-microbe interaction is shaped by the immune system response, it is important to understand the key immune system-microbiota relationship during the period from conception to the first years of life. The present work summarizes the available evidence concerning human reproductive microbiota, and also, the microbial colonization during early life, focusing on the potential impact on infant development and health outcomes. Furthermore, we conclude that some dietary strategies including specific probiotics and other-biotics could become potentially valuable tools to modulate the maternal-neonatal microbiota during this early critical window of opportunity for targeted health outcomes throughout the entire lifespan.

Investigating prenatal and perinatal factors on meconium microbiota: a systematic review and cohort study

BACKGROUND

The first-pass meconium has been suggested as a proxy for the fetal gut microbiota because it is formed in utero. This systematic review and cohort study investigated how pre- and perinatal factors influence the composition of the meconium microbiota.

METHODS

We performed the systematic review using Covidence by searching PubMed, Scopus, and Web of Science databases with the search terms "meconium microbiome" and "meconium microbiota". In the cohort study, we performed 16 S rRNA gene sequencing on 393 meconium samples and analyzed the sequencing data using QIIME2.

RESULTS

Our systematic review identified 69 studies exploring prenatal factors, immediate perinatal factors, and microbial composition in relation to subsequent health of infants but gave only limited comparative evidence regarding factors related to the composition of the meconium microbiota. The cohort study pointed to a low-biomass microbiota consisting of the phyla Firmicutes, Proteobacteria and Actinobacteriota and the genera Staphylococcus, Escherichia-Shigella and Lactobacillus, and indicated that immediate perinatal factors affected the composition of the meconium microbiota more than did prenatal factors.

CONCLUSIONS

This finding supports the idea that the meconium microbiota mostly starts developing during delivery.

IMPACT

It is unclear when the first-pass meconium microbiota develops, and what are the sources of the colonization. In this systematic review, we found 69 studies exploring prenatal factors, immediate perinatal factors, and microbial composition relative to subsequent health of infants, but there was no consensus on the factors affecting the meconium microbiota development. In this cohort study, immediate perinatal factors markedly affected the meconium microbiota development while prenatal factors had little effect on it. As the meconium microbiota composition was influenced by immediate perinatal factors, the present study supports the idea that the initial gut microbiota develops mainly during delivery.

Impacts of gut microbiota alteration on age-related chronic liver diseases

The gut microbiome and its metabolites are involved in developing and progressing liver disease. Various liver illnesses, such as non-alcoholic fatty liver disease, alcoholic liver disease, hepatitis C, and hepatocellular carcinoma, are made worse and have worse prognoses with aging. Dysbiosis, which occurs when the symbiosis between the microbiota and the host is disrupted, can significantly negatively impact health. Liver disease is linked to qualitative changes, such as an increase in hazardous bacteria and a decrease in good bacteria, as well as quantitative changes in the overall amount of bacteria (overgrowth). Intestinal gut microbiota and their metabolites may lead to chronic liver disease development through various mechanisms, such as increasing gut permeability, persistent systemic inflammation, production of SCFA, bile acids, and alteration in metabolism. Age-related gut dysbiosis can disrupt the communication between gut microbiota and the host, impacting the host's health and lifespan. With aging, a gradual loss of the ability to maintain homeostasis because of structural alteration and gut dysbiosis leads to the disease progression in end-stage liver disease. Recently chronic liver disease has been identified as a global problem. A large number of patients are receiving liver transplants yearly. Thereby gut microbiome ecology is changing in the patients of the gut due to the changes in pathophysiology during the preoperative stage. The present review summarises the age-associated dysbiosis of gut microbial composition and its contribution to chronic liver disease. This review also provides information about the impact of liver transplant on the gut microbiome and possible disadvantageous effects of alteration in gut microbiota.

Impact of Maternal Mediterranean-Type Diet Adherence on Microbiota Composition and Epigenetic Programming of Offspring

Understanding how maternal diet affects in utero neonatal gut microbiota and epigenetic regulation may provide insight into disease origins and long-term health. The impact of Mediterranean diet pattern adherence (MDA) on fetal gut microbiome and epigenetic regulation was assessed in 33 pregnant women. Participants completed a validated food frequency questionnaire in each trimester of pregnancy; the alternate Mediterranean diet (aMED) score was applied. Umbilical cord blood, placental tissue, and neonatal meconium were collected from offspring. DNA methylation patterns were probed using the Illumnia EPICarray Methylation Chip in parturients with high versus low MDA. Meconium microbial abundance in the first 24 h after birth was identified using 16s rRNA sequencing and compared among neonates born to mothers with high and low aMED scores. Twenty-one mothers were classified as low MDA and 12 as high MDA. Pasteurellaceae and Bacteroidaceae trended towards greater abundance in the high-MDA group, as well as other short-chain fatty acid-producing species. Several differentially methylated regions varied between groups and overlapped gene regions including NCK2, SNED1, MTERF4, TNXB, HLA-DPB, BAG6, and LMO3. We identified a beneficial effect of adherence to a Mediterranean diet on fetal in utero development. This highlights the importance of dietary counseling for mothers and can be used as a guide for future studies of meconium and immuno-epigenetic modulation.

From Mother to Infant, from Placenta to Gut: Understanding Varied Microbiome Profiles in Neonates

The field of human microbiome and gut microbial diversity research has witnessed a profound transformation, driven by advances in omics technologies. These advancements have unveiled essential connections between microbiome alterations and severe conditions, prompting the development of new frameworks through epidemiological studies. Traditionally, it was believed that each individual harbored unique microbial communities acquired early in life, evolving over the course of their lifetime, with little acknowledgment of any prenatal microbial development, but recent research challenges this belief. The neonatal microbiome's onset, influenced by factors like delivery mode and maternal health, remains a subject of intense debate, hinting at potential intrauterine microbial processes. In-depth research reveals associations between microbiome profiles and specific health outcomes, ranging from obesity to neurodevelopmental disorders. Understanding these diverse microbiome profiles is essential for unraveling the intricate relationships between the microbiome and health outcomes.

Exploring the effect of prenatal maternal stress on the microbiomes of mothers and infants: A systematic review

Prenatal maternal stress (PNMS)-characterized by exposure to stress, anxiety, depression, or intimate partner violence-has been linked to biological alterations in infants, including disruptions to their intestinal microbiota, which have long-term implications for children's developmental outcomes. Significant research has been done examining the effects of PNMS on the microbiome in animals, but less is known about these effects in human research. The current systematic review aimed to synthesize current findings on the association between PNMS and mother and infant microbiomes. Medline, Embase, PsycInfo, Web of Science, and Eric databases were searched through to February 2022. A total of eight studies (n = 2219 infants, 2202 mothers) were included in the qualitative synthesis. Findings provided promising evidence of the role that PNMS plays in altering the microbial composition, diversity, and gut immunity in mothers and infants. Notably, majority of included studies found that higher PNMS was linked to increases in genera from the phylum Proteobacteria. The factors influencing these effects are explored including nutrition, birth mode, and parenting behaviors. Potential interventions to mitigate the adverse effects of PNMS are discussed, along with recommendations for future studies with longitudinal designs to better understand the appropriate type and timing of interventions needed to promote "healthy" maternal and infant microbial functioning.

From heart to gut: Exploring the gut microbiome in congenital heart disease

Congenital heart disease (CHD) is a prevalent birth defect and a significant contributor to childhood mortality. The major characteristics of CHD include cardiovascular malformations and hemodynamical disorders. However, the impact of CHD extends beyond the circulatory system. Evidence has identified dysbiosis of the gut microbiome in patients with CHD. Chronic hypoxia and inflammation associated with CHD affect the gut microbiome, leading to alterations in its number, abundance, and composition. The gut microbiome, aside from providing essential nutrients, engages in direct interactions with the host immune system and indirect interactions via metabolites. The abnormal gut microbiome or its products can translocate into the bloodstream through an impaired gut barrier, leading to an inflammatory state. Metabolites of the gut microbiome, such as short-chain fatty acids and trimethylamine N-oxide, also play important roles in the development, treatment, and prognosis of CHD. This review discusses the role of the gut microbiome in immunity, gut barrier, neurodevelopment, and perioperative period in CHD. By fostering a better understanding of the cross-talk between CHD and the gut microbiome, this review aims to contribute to improve clinical management and outcomes for CHD patients.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

Distinguishable Influence of the Delivery Mode, Feeding Pattern, and Infant Sex on Dynamic Alterations in the Intestinal Microbiota in the First Year of Life

The delivery mode, the feeding pattern and infant sex significantly influence the development of the infant gut flora. However, the extent to which these factors contribute to the establishment of the gut microbiota at different stages has rarely been studied. The factors that play a dominant role in determining microbial colonization of the infant gut at specific time points are unknown. The purpose of this study was to assess the different contributions of the delivery mode, the feeding pattern and infant sex to the composition of the infant gut microbiome. Here, 213 fecal samples from 55 infants at five ages (0, 1, 3, 6, and 12 months postpartum) were collected, and the composition of the gut microbiota via 16S rRNA sequencing was analyzed. The results showed that the average relative abundances of four genera, Bifidobacterium, Bacteroides, Parabacteroides, and Phascolarctobacterium, were increased in vaginally delivered infants versus cesarean section-delivered infants, while those of ten genera, such as Salmonella and Enterobacter, were reduced. The relative proportions of Anaerococcus and Peptostreptococcaceae were higher in exclusive breastfeeding than in combined feeding, while those of Coriobacteriaceae, Lachnospiraceae and Erysipelotrichaceae were lower. The average relative abundances of two genera, Alistipes and Anaeroglobus, were increased in male infants compared with female infants, whereas those of the phyla Firmicutes and Proteobacteria were reduced. During the first year of life, the average UniFrac distances revealed that the individual difference in the gut microbial composition in vaginally delivered infants was greater than that in cesarean section-delivered infants (P < 0.001) and that infants who received combined feeding had greater individual microbiota differences than exclusively breastfed infants (P < 0.01). The delivery mode, infant sex, and the feeding pattern were the dominant factors determining colonization of the infant gut microbiota at 0 months, from 1 to 6 months, and at 12 months postpartum, respectively. This study demonstrated for the first time that infant sex accounted for the dominant contribution to infant gut microbial development from 1 to 6 months postpartum. More broadly, this study effectively established the extent to which the delivery mode, the feeding pattern and infant sex contribute to the development of the gut microbiota at various time points during the first year of life.

Associations of intrapartum antibiotics and growth, atopy, gastrointestinal and sleep outcomes at one year of age

BACKGROUND

Studies investigating neonatal outcomes following intrapartum antibiotic exposure show conflicting results.

METHODS

Data were collected prospectively in pregnancy to 1-year-of-age, from 212 mother-infant pairs. Adjusted multivariable regression models estimated relationships following exposure to intrapartum antibiotics among vaginally-born, full-term infants and outcomes related to growth, atopic disease, gastrointestinal symptoms, and sleep at 1-year.

RESULTS

Intrapartum antibiotic exposure (n = 40) was not associated with mass, ponderal index, BMI z-score (1- year), lean mass index (5-months) or height. Antibiotic exposure in labour ≥4-h was associated with increase in fat mass index at 5-months (β 0.42 [95% CI: 0.03, 0.80], p = 0.03). Intrapartum antibiotic was associated with atopy in the first year (OR: 2.93 [95% CI: 1.34, 6.43], p = 0.007). Antibiotic exposure during intrapartum or day 1-7 was associated with newborn fungal infection requiring antifungal therapy (OR 3.04 [95% CI: 1.14, 8.10], p = 0.026), and number of fungal infections (IRR: 2.90 [95% CI: 1.02, 8.27], p = 0.046).

CONCLUSION

Intrapartum and early life exposure to antibiotics were independently associated with measures of growth, atopy, and fungal infections suggesting that intrapartum and early neonatal antibiotics be used prudently following careful risk-benefit analysis.

IMPACT

This prospective study: Shows a shift in fat mass index at 5 months associated with antibiotic administration ≥4 h in labour; an earlier age than previously reported; Shows atopy reported less frequently among those not exposed to intrapartum antibiotics; Supports earlier research of increased likelihood of fungal infection following exposure to intrapartum or early-life antibiotics; Adds to growing evidence that antibiotics used intrapartum and in early neonatal periods influence longer-term outcomes for infants. Suggests that use of intrapartum and early neonatal antibiotics should be used prudently after careful consideration of risk and benefit.

Microbiome analysis of maternal and neonatal microbial communities associated with the different delivery modes based on 16S rRNA gene amplicon sequencing

OBJECTIVE

With the rising number of cases of non-vaginal delivery worldwide, scientists have been concerned about the influence of the different delivery modes on maternal and neonatal microbiomes. Although the birth rate trend is decreasing rapidly in Taiwan, more than 30 percent of newborns are delivered by caesarean section every year. However, it remains unclear whether the different delivery modes could have a certain impact on the postpartum maternal microbiome and whether it affects the mother-to-newborn vertical transmission of bacteria at birth.

MATERIALS AND METHODS

To address this, we recruited 30 mother-newborn pairs to participate in this study, including 23 pairs of vaginal delivery (VD) and seven pairs of caesarean section (CS). We here investigate the development of the maternal prenatal and postnatal microbiomes across multiple body habitats. Moreover, we also explore the early acquisition of neonatal gut microbiome through a vertical multi-body site microbiome analysis.

RESULTS AND CONCLUSION

The results indicate that no matter the delivery mode, it only slightly affects the maternal microbiome in multiple body habitats from pregnancy to postpartum. On the other hand, about 95% of species in the meconium microbiome were derived from one of the maternal body habitats; notably, the infants born by caesarean section acquire bacterial communities resembling their mother's oral microbiome. Consequently, the delivery modes play a crucial role in the initial colonization of the neonatal gut microbiome, potentially impacting children's health and development.

Infant gut microbiota colonization: influence of prenatal and postnatal factors, focusing on diet

Maternal microbiota forms the first infant gut microbial inoculum, and perinatal factors (diet and use of antibiotics during pregnancy) and/or neonatal factors, like intra partum antibiotics, gestational age and mode of delivery, may influence microbial colonization. After birth, when the principal colonization occurs, the microbial diversity increases and converges toward a stable adult-like microbiota by the end of the first 3-5 years of life. However, during the early life, gut microbiota can be disrupted by other postnatal factors like mode of infant feeding, antibiotic usage, and various environmental factors generating a state of dysbiosis. Gut dysbiosis have been reported to increase the risk of necrotizing enterocolitis and some chronic diseases later in life, such as obesity, diabetes, cancer, allergies, and asthma. Therefore, understanding the impact of a correct maternal-to-infant microbial transfer and a good infant early colonization and maturation throughout life would reduce the risk of disease in early and late life. This paper reviews the published evidence on early-life gut microbiota development, as well as the different factors influencing its evolution before, at, and after birth, focusing on diet and nutrition during pregnancy and in the first months of life.

Development of Gut Microbiota in the First 1000 Days after Birth and Potential Interventions

The first 1000 days after birth represent a critical window for gut microbiome development, which is essential for immune system maturation and overall health. The gut microbiome undergoes major changes during this period due to shifts in diet and environment. Disruptions to the microbiota early in life can have lasting health effects, including increased risks of inflammatory disorders, autoimmune diseases, neurological disorders, and obesity. Maternal and environmental factors during pregnancy and infancy shape the infant gut microbiota. In this article, we will review how maintaining a healthy gut microbiome in pregnancy and infancy is important for long-term infant health. Furthermore, we briefly include fungal colonization and its effects on the host immune function, which are discussed as part of gut microbiome ecosystem. Additionally, we will describe how potential approaches such as hydrogels enriched with prebiotics and probiotics, gut microbiota transplantation (GMT) during pregnancy, age-specific microbial ecosystem therapeutics, and CRISPR therapies targeting the gut microbiota hold potential for advancing research and development. Nevertheless, thorough evaluation of their safety, effectiveness, and lasting impacts is crucial prior to their application in clinical approach. The article emphasizes the need for continued research to optimize gut microbiota and immune system development through targeted early-life interventions.

Genomic analysis of Enterococcus faecium strain RAOG174 associated with acute chorioamnionitis carried antibiotic resistance gene: is it time for precise microbiological identification for appropriate antibiotic use?

BACKGROUND

Preterm labor syndrome is associated with high perinatal morbidity and mortality, and intra-amniotic infection is a cause of preterm labor. The standard identification of causative microorganisms is based on the use of biochemical phenotypes, together with broth dilution-based antibiotic susceptibility from organisms grown in culture. However, such methods could not provide an accurate epidemiological aspect and a genetic basis of antimicrobial resistance leading to an inappropriate antibiotic administration. Hybrid genome assembly is a combination of short- and long-read sequencing, which provides better genomic resolution and completeness for genotypic identification and characterization. Herein, we performed a hybrid whole genome assembly sequencing of a pathogen associated with acute histologic chorioamnionitis in women presenting with PPROM.

RESULTS

We identified Enterococcus faecium, namely E. faecium strain RAOG174, with several antibiotic resistance genes, including vancomycin and aminoglycoside. Virulence-associated genes and potential bacteriophage were also identified in this genome.

CONCLUSION

We report herein the first study demonstrating the use of hybrid genome assembly and genomic analysis to identify E. faecium ST17 as a pathogen associated with acute histologic chorioamnionitis. The analysis provided several antibiotic resistance-associated genes/mutations and mobile genetic elements. The occurrence of E. faecium ST17 raised the awareness of the colonization of clinically relevant E. faecium and the carrying of antibiotic resistance. This finding has brought the advantages of genomic approach in the identification of the bacterial species and antibiotic resistance gene for E. faecium for appropriate antibiotic use to improve maternal and neonatal care.

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.

Human Microbiome Mixture Analysis Using Weighted Quantile Sum Regression

Studies of the health effects of the microbiome often measure overall associations by using diversity metrics, and individual taxa associations in separate analyses, but do not consider the correlated relationships between taxa in the microbiome. In this study, we applied random subset weighted quantile sum regression with repeated holdouts (WQSRSRH), a mixture method successfully applied to 'omic data to account for relationships between many predictors, to processed amplicon sequencing data from the Human Microbiome Project. We simulated a binary variable associated with 20 operational taxonomic units (OTUs). WQSRSRH was used to test for the association between the microbiome and the simulated variable, adjusted for sex, and sensitivity and specificity were calculated. The WQSRSRH method was also compared to other standard methods for microbiome analysis. The method was further illustrated using real data from the Growth and Obesity Cohort in Chile to assess the association between the gut microbiome and body mass index. In the analysis with simulated data, WQSRSRH predicted the correct directionality of association between the microbiome and the simulated variable, with an average sensitivity and specificity of 75% and 70%, respectively, in identifying the 20 associated OTUs. WQSRSRH performed better than all other comparison methods. In the illustration analysis of the gut microbiome and obesity, the WQSRSRH analysis identified an inverse association between body mass index and the gut microbe mixture, identifying Bacteroides, Clostridium, Prevotella, and Ruminococcus as important genera in the negative association. The application of WQSRSRH to the microbiome allows for analysis of the mixture effect of all the taxa in the microbiome, while simultaneously identifying the most important to the mixture, and allowing for covariate adjustment. It outperformed other methods when using simulated data, and in analysis with real data found results consistent with other study findings.

Epigenetics in depression and gut-brain axis: A molecular crosstalk

Gut-brain axis is a dynamic, complex, and bidirectional communication network between the gut and brain. Changes in the microbiota-gut-brain axis are responsible for developing various metabolic, neurodegenerative, and neuropsychiatric disorders. According to clinical and preclinical findings, the gut microbiota is a significant regulator of the gut-brain axis. In addition to interacting with intestinal cells and the enteric nervous system, it has been discovered that microbes in the gut can modify the central nervous system through metabolic and neuroendocrine pathways. The metabolites of the gut microbiome can modulate a number of diseases by inducing epigenetic alteration through DNA methylation, histone modification, and non-coding RNA-associated gene silencing. Short-chain fatty acids, especially butyrate, are well-known histone deacetylases inhibitors. Similarly, other microbial metabolites such as folate, choline, and trimethylamine-N-oxide also regulate epigenetics mechanisms. Furthermore, various studies have revealed the potential role of microbiome dysbiosis and epigenetics in the pathophysiology of depression. Hence, in this review, we have highlighted the role of gut dysbiosis in epigenetic regulation, causal interaction between host epigenetic modification and the gut microbiome in depression and suggest microbiome and epigenome as a possible target for diagnosis, prevention, and treatment of depression.

The Role of the Gut Microbiome in Cow's Milk Allergy: A Clinical Approach

Cow's milk allergy (CMA) is the most prevalent food allergy (FA) in infancy and early childhood and can be present with various clinical phenotypes. The significant increase in FA rates recorded in recent decades has been associated with environmental and lifestyle changes that limit microbial exposure in early life and induce changes in gut microbiome composition. Gut microbiome is a diverse community of microbes that colonize the gastrointestinal tract (GIT) and perform beneficial functions for the host. This complex ecosystem interacts with the immune system and has a pivotal role in the development of oral tolerance to food antigens. Emerging evidence indicates that alterations of the gut microbiome (dysbiosis) in early life cause immune dysregulation and render the host susceptible to immune-mediated diseases later in life. Therefore, the colonization of the gut by "healthy" microbes that occurs in the first years of life determines the lifelong health of the host. Here, we present current data on the possible role of the gut microbiome in the development of CMA. Furthermore, we discuss how gut microbiome modification might be a potential strategy for CMA prevention and treatment.

Nutrition, Gut Microbiota, and Allergy Development in Infants

The process of gut microbiota development in infants is currently being challenged by numerous factors associated with the contemporary lifestyle, including diet. A thorough understanding of all aspects of microbiota development will be necessary for engineering strategies that can modulate it in a beneficial direction. The long-term consequences for human development and health of alterations in the succession pattern that forms the gut microbiota are just beginning to be explored and require much further investigation. Nevertheless, it is clear that gut microbiota development in infancy bears strong associations with the risk for allergic disease. A useful understanding of microbial succession in the gut of infants needs to reveal not only changes in taxonomic composition but also the development of functional capacities through time and how these are related to diet and various environmental factors. Metagenomic and metatranscriptomic studies have started to produce insights into the trends of functional repertoire and gene expression change within the first year after birth. This understanding is critical as during this period the most substantial development of the gut microbiota takes place and the relations between gut microbes and host immunity are established. However, further research needs to focus on the impact of diet on these changes and on how diet can be used to counteract the challenges posed by modern lifestyles to microbiota development and reduce the risk of allergic disease.

Crucial nuances in understanding (mis)associations between the neonatal microbiome and Cesarean delivery

As rates of Cesarean delivery and common non-communicable disorders (NCDs), such as obesity, metabolic disease, and atopy/asthma, have concomitantly increased in recent decades, investigators have attempted to discern a causal link. One line of research has led to a hypothesis that Cesarean birth disrupts the presumed normal process of colonization of the neonatal microbiome with vaginal microbes, yielding NCDs later in life. However, a direct link between a disrupted microbiota transfer at time of delivery and acute and/or chronic illness in infants born via Cesarean has not been causally established. Microbiota seeding from maternal vaginal or stool sources has been preliminarily evaluated as an intervention designed to compensate for the lack of (or limited) exposure to such sources among Cesarean-delivered neonates. However, to date, clinical trials have yet to show a clear health benefit with neonatal 'vaginal seeding' practices. Until the long-term effects of these microbiome alterations can be fully determined, it is paramount to conduct parallel meaningful and mechanistic-minded interrogations of the impact of clinically modifiable maternal, nutritional, or environmental exposure on the functional microbiome over the duration of pregnancy and lactation to determine their role in the mitigation of childhood and adult NCDs.

Exploring the Potential of Human Milk and Formula Milk on Infants’ Gut and Health

Early-life gut microbiota plays a role in determining the health and risk of developing diseases in later life. Various perinatal factors have been shown to contribute to the development and establishment of infant gut microbiota. One of the important factors influencing the infant gut microbial colonization and composition is the mode of infant feeding. While infant formula milk has been designed to resemble human milk as much as possible, the gut microbiome of infants who receive formula milk differs from that of infants who are fed human milk. A diverse microbial population in human milk and the microbes seed the infant gut microbiome. Human milk contains nutritional components that promote infant growth and bioactive components, such as human milk oligosaccharides, lactoferrin, and immunoglobulins, which contribute to immunological development. In an attempt to encourage the formation of a healthy gut microbiome comparable to that of a breastfed infant, manufacturers often supplement infant formula with prebiotics or probiotics, which are known to have a bifidogenic effect and can modulate the immune system. This review aims to elucidate the roles of human milk and formula milk on infants’ gut and health.

Gut microbiota in women with gestational diabetes mellitus has potential impact on metabolism in pregnant mice and their offspring

Studies have shown that gestational diabetes mellitus (GDM) is closely related to abnormalities in the gut microbiota, and the offspring of these women have an increased risk of diabetes. There is no direct evidence of whether bacteria in women with GDM colonize the intestinal tract of offspring and cause hyperglycemia. In this fecal microbiota transplantation (FMT), pregnant mouse model study, two groups of germ-free (GF) mice after FMT showed different colonization patterns of gut microbiota and phenotype. Compared with the control group (healthy-FMT), we found in the GDM-FMT group as a lower relative abundance of Akkermansia and Faecalibacterium; a lower content of short-chain fatty acids and naringenin in feces; an elevated blood glucose; an inflammatory factor expression (TNF-α, CXCL-15, and IL-6), and a hepatic fat deposition. In addition, the influence of the gut microbiota continued in offspring. The gut microbiota of the offspring of GDM-FMT mice was still different from that of the control group as a lower relative abundance of Akkermansia and Parvibacter; and a higher relative abundance of bacteria such as Oscillibacter, Romboutsia, and Harryflintia. In addition, the offspring of GDM-FMT mice had higher body weight and blood glucose levels than the control offspring.

The Complex Link and Disease Between the Gut Microbiome and the Immune System in Infants

The human gut microbiome is important for human health. The development of stable microbial communities in the gastrointestinal tract is closely related to the early growth and development of host immunity. After the birth of a baby, immune cells and the gut microbiome mature in parallel to adapt to the complex gut environment. The gut microbiome is closely linked to the immune system and influences each other. This interaction is associated with various diseases in infants and young children, such as asthma, food allergies, necrotizing colitis, obesity, and inflammatory bowel disease. Thus, the composition of the infant gut microbiome can predict the risk of disease development and progression. At the same time, the composition of the infant gut microbiome can be regulated in many ways and can be used to prevent and treat disease in infants by modulating the composition of the infant gut microbiome. The most important impacts on infant gut microbiota are maternal, including food delivery and feeding. The differences in the gut microbiota of infants reflect the maternal gut microbiota, which in turn reflects the gut microbiota of a given population, which is clinically significant.

The Role of Microbiota in the Immunopathogenesis of Endometrial Cancer

The female reproductive tract hosts a specific microbiome, which plays a crucial role in sustaining equilibrium and good health. In the majority of reproductive women, the microbiota (all bacteria, viruses, fungi, and other single-celled organisms within the human body) of the vaginal and cervical microenvironment are dominated by Lactobacillus species, which benefit the host through symbiotic relationships, in comparison to the uterus, fallopian tubes, and ovaries, which may contain a low-biomass microbiome with a diverse mixture of microorganisms. Although disruption to the balance of the microbiota develops, the altered immune and metabolic signaling may cause an impact on diseases such as cancer. These pathophysiological modifications in the gut–uterus axis may spark gynecological cancers. New information displays that gynecological and gastrointestinal tract dysbiosis (disruption of the microbiota homeostasis) can play an active role in the advancement and metastasis of gynecological neoplasms, such as cervical, endometrial, and ovarian cancers. Understanding the relationship between microbiota and endometrial cancer is critical for prognosis, diagnosis, prevention, and the development of innovative treatments. Identifying a specific microbiome may become an effective method for characterization of the specific microbiota involved in endometrial carcinogenesis. The aim of this study was to summarize the current state of knowledge that describes the correlation of microbiota with endometrial cancer with regard to the formation of immunological pathologies.

Role of gene regulation and inter species interaction as a key factor in gut microbiota adaptation

Gut microbiota is a class of microbial flora present in various eukaryotic multicellular complex animals such as human beings. Their community's growth and survival are greatly influenced by various factors such as host-pathogen, pathogen-environment and genetic regulation. Modern technologies like metagenomics have particularly extended our capacity to uncover the microbial treasures in challenging conditions like communities surviving at high altitude. Molecular characterizations by newly developed sequencing tools have shown that this complex interaction greatly influences microbial adaptation to the environment. Literature shows that gut microbiota alters the genetic expression and switches to an alternative pathway under the influence of unfavorable conditions. The remarkable adaptability of microbial genetic regulatory networks enables them to survive and expand in tough and energy-limited conditions. Variable prevalence of species in various regions has strengthened this initial evidence. In view of the interconnection of the world in the form of a global village, this phenomenon must be explored more clearly. In this regard, recently there has been significant addition of knowledge to the field of microbial adaptation. This review summarizes and shed some light on mechanisms of microbial adaptation via gene regulation and species interaction in gut microbiota.

The developing infant gut microbiome: A strain-level view

At birth, neonates provide a vast habitat awaiting microbial colonization. Microbiome assembly is a complex process involving microbial seeding and succession driven by ecological forces and subject to environmental conditions. These successional events not only significantly affect the ecology and function of the microbiome, but also impact host health. While the establishment of the infant microbiome has been a point of interest for decades, an integrated view focusing on strain level colonization has been lacking until recently. Technological and computational advancements enabling strain-level analyses of the infant microbiome have demonstrated the immense complexity of this system and allowed for an improved understanding of how strains of the same species spread, colonize, evolve, and affect the host. Here, we review the current knowledge of the establishment and maturation of the infant gut microbiome with particular emphasis on newer discoveries achieved through strain-centric analyses.

Microbiota of the first-pass meconium and subsequent atopic and allergic disorders in children

BACKGROUND

Some cohort studies have suggested that gut microbiota composition is associated with allergic diseases in children. The microbiota of the first-pass meconium, which forms before birth, represents the first gut microbiota that is easily available for research and little is known about any relationship with allergic disease development.

OBJECTIVE

We investigated whether the bacterial composition of the first-pass meconium is associated with the development of allergic diseases before 4 years of age.

METHODS

Prospective birth cohort study. Bacterial composition of first-pass meconium was analysed using bacterial 16S rRNA gene amplicon sequencing. Atopic and allergic diseases were evaluated via online survey or telephone to age 4 years, based on the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

During a 6-week period in 2014, 312 children were born at the Central Finland Central Hospital. Meconium was collected from 212 at a mean of 8-hour age. Outcome data at 4 years were available for 177 (83%) children, and 159 of these had sufficient amplification of bacterial DNA in meconium. Meconium microbiota composition, including diversity indices and relative abundances of the main phyla and genera, was not associated with subsequent atopic eczema, wheezing or cow's milk allergy. Principal components analysis did not identify any clustering of the meconium microbiomes of children with respect to wheezing or cow's milk allergy.

CONCLUSIONS

We found no evidence that gut microbiota composition of first-pass meconium is associated with atopic manifestations to age 4 years. However, larger studies are needed to fully exclude a relationship.

Comprehensive human amniotic fluid metagenomics supports the sterile womb hypothesis

As metagenomic approaches for detecting infectious agents have improved, each tissue that was once thought to be sterile has been found to harbor a variety of microorganisms. Controversy still exists over the status of amniotic fluid, which is part of an immunologically privileged zone that is required to prevent maternal immune system rejection of the fetus. Due to this privilege, the exclusion of microbes has been proposed to be mandatory, leading to the sterile womb hypothesis. Since nucleic acid yields from amniotic fluid are very low, contaminating nucleic acid found in water, reagents and the laboratory environment frequently confound attempts to address this hypothesis. Here we present metagenomic criteria for microorganism detection and a metagenomic method able to be performed with small volumes of starting material, while controlling for exogenous contamination, to circumvent these and other pitfalls. We use this method to show that human mid-gestational amniotic fluid has no detectable virome or microbiome, supporting the sterile womb hypothesis.

The Role of the Crosstalk Between Gut Microbiota and Immune Cells in the Pathogenesis and Treatment of Multiple Myeloma

Around 10% of all hematologic malignancies are classified as multiple myeloma (MM), the second most common malignancy within that group. Although massive progress in developing of new drugs against MM has been made in recent years, MM is still an incurable disease, and every patient eventually has relapse refractory to any known treatment. That is why further and non-conventional research elucidating the role of new factors in MM pathogenesis is needed, facilitating discoveries of the new drugs. One of these factors is the gut microbiota, whose role in health and disease is still being explored. This review presents the continuous changes in the gut microbiota composition during our whole life with a particular focus on its impact on our immune system. Additionally, it mainly focuses on the chronic antigenic stimulation of B-cells as the leading mechanism responsible for MM promotion. The sophisticated interactions between microorganisms colonizing our gut, immune cells (dendritic cells, macrophages, neutrophils, T/B cells, plasma cells), and intestinal epithelial cells will be shown. That article summarizes the current knowledge about the initiation of MM cells, emphasizing the role of microorganisms in that process.

Comparing the maternal-fetal microbiome of humans and cattle: a translational assessment of the reproductive, placental, and fetal gut microbiomes

An analysis of sites within the maternal reproductive microbiome that potentially contribute to fetal gut microbial colonization, with a special focus on the comparison between humans and cattle.

Of Cockroaches and Symbionts: Recent Advances in the Characterization of the Relationship between Blattella germanica and Its Dual Symbiotic System

Mutualistic stable symbioses are widespread in all groups of eukaryotes, especially in insects, where symbionts have played an essential role in their evolution. Many insects live in obligate relationship with different ecto- and endosymbiotic bacteria, which are needed to maintain their hosts’ fitness in their natural environment, to the point of even relying on them for survival. The case of cockroaches (Blattodea) is paradigmatic, as both symbiotic systems coexist in the same organism in two separated compartments: an intracellular endosymbiont (Blattabacterium) inside bacteriocytes located in the fat body, and a rich and complex microbiota in the hindgut. The German cockroach Blattella germanica is a good model for the study of symbiotic interactions, as it can be maintained in the laboratory in controlled populations, allowing the perturbations of the two symbiotic systems in order to study the communication and integration of the tripartite organization of the host–endosymbiont–microbiota, and to evaluate the role of symbiotic antimicrobial peptides (AMPs) in host control over their symbionts. The importance of cockroaches as reservoirs and transmission vectors of antibiotic resistance sequences, and their putative interest to search for AMPs to deal with the problem, is also discussed.

Understanding the pathways leading to gut dysbiosis and enteric environmental dysfunction in infants: the influence of maternal dysbiosis and other microbiota determinants during early life

Maternal environmental enteric dysfunction (EED) encompasses undernutrition with an inflammatory gut profile, a variable degree of dysbiosis and increased translocation of pathogens in the gut mucosa. Even though recent research findings have shed light on the pathological pathways underlying the establishment of the infant gut dysbiosis, evidence on how maternal EED influences the development of gut dysbiosis and EED in the offspring remains elusive. This review summarizes the current knowledge on the effect of maternal dysbiosis and EED on infant health, and explores recent progress in unraveling the mechanisms of acquisition of a dysbiotic gut microbiota in the offspring. In Western communities, maternal inoculum, delivery mode, perinatal antibiotics, feeding practices, and infections are the major drivers of the infant gut microbiota during the first two years of life. In other latitudes, the infectious burden and maternal malnutrition might introduce further risk factors for infant gut dysbiosis. Novel tools, such as transcriptomics and metabolomics, have become indispensable to analyze the metabolic environment of the infant in utero and post-partum. Human-milk oligosaccharides have essential prebiotic, antimicrobial, and anti-biofilm properties that might offer additional therapeutic opportunities.

The impact of the gut microbiota on the reproductive and metabolic endocrine system

As the gut microbiota exerts various effects on the intestinal milieu which influences distant organs and pathways, it is considered to be a full-fledged endocrine organ. The microbiota plays a major role in the reproductive endocrine system throughout a woman's lifetime by interacting with estrogen, androgens, insulin, and other hormones. Imbalance of the gut microbiota composition can lead to several diseases and conditions, such as pregnancy complications, adverse pregnancy outcomes, polycystic ovary syndrome (PCOS), endometriosis, and cancer; however, research on the mechanisms is limited. More effort should be concentrated on exploring the potential causes and underlying the mechanisms of microbiota-hormone-mediated disease, and providing novel therapeutic and preventive strategies.As the gut microbiota exerts various effects on the intestinal milieu which influences distant organs and pathways, it is considered to be a full-fledged endocrine organ. The microbiota plays a major role in the reproductive endocrine system throughout a woman's lifetime by interacting with estrogen, androgens, insulin, and other hormones. Imbalance of the gut microbiota composition can lead to several diseases and conditions, such as pregnancy complications, adverse pregnancy outcomes, polycystic ovary syndrome (PCOS), endometriosis, and cancer; however, research on the mechanisms is limited. More effort should be concentrated on exploring the potential causes and underlying the mechanisms of microbiota-hormone-mediated disease, and providing novel therapeutic and preventive strategies.

From Intrauterine to Extrauterine Life-The Role of Endogenous and Exogenous Factors in the Regulation of the Intestinal Microbiota Community and Gut Maturation in Early Life

Differentiation of the digestive tube and formation of the gut unit as a whole, are regulated by environmental factors through epigenetic modifications which enhance cellular plasticity. The critical period of DNA imprinting lasts from conception until approximately the 1,000th day of human life. During pregnancy, besides agents that may directly promote epigenetic programming (e.g., folate, zinc, and choline supplementation), some factors (e.g., antibiotic use, dietary components) can affect the composition of the mother's microbiota, in turn affecting the fetal microbiome which interacts with the offspring's intestinal epithelial cells. According to available literature that confirms intrauterine microbial colonization, the impact of the microbiome and its metabolites on the genome seems to be key in fetal development, including functional gut maturation and the general health status of the offspring, as well as later on in life. Although the origin of the fetal microbiome is still not well-understood, the bacteria may originate from both the vagina, as the baby is born, as well as from the maternal oral cavity/gut, through the bloodstream. Moreover, the composition of the fetal gut microbiota varies depending on gestational age, which in turn possibly affects the regulation of the immune system at the barrier between mother and fetus, leading to differences in the ability of microorganisms to access and survive in the fetal environment. One of the most important local functions of the gut microbiota during the prenatal period is their exposure to foreign antigens which in turn contributes to immune system and tissue development, including fetal intestinal Innate Lymphoid Cells (ILCs). Additional factors that determine further infant microbiome development include whether the infant is born premature or at term, the method of delivery, maternal antibiotic use, and the composition of the mother's milk, among others. However, the latest findings highlight the fact that a more diverse infant gut microbiome at birth facilitates the proliferation of stem cells by microbial metabolites and accelerates infant development. This phenomenon confirms the unique role of microbiome. This review emphasizes the crucial perinatal and postnatal factors that may influence fetal and neonatal microbiota, and in turn gut maturation.

Fecal microbiota relationships with childhood obesity: A scoping comprehensive review

Childhood obesity is a costly burden in most regions with relevant and adverse long-term health consequences in adult life. Several studies have associated excessive body weight with a specific profile of gut microbiota. Different factors related to fecal microorganism abundance seem to contribute to childhood obesity, such as gestational weight gain, perinatal diet, antibiotic administration to the mother and/or child, birth delivery, and feeding patterns, among others. This review reports and discusses diverse factors that affect the infant intestinal microbiota with putative or possible implications on the increase of the obesity childhood rates as well as microbiota shifts associated with excessive body weight in children.