Microbiota of newborn meconium is associated with maternal anxiety experienced during pregnancy

Association between maternal stress patterns and neonatal meconium microbiota: A prospective cohort study

BACKGROUND

This study aimed to identify maternal stress patterns and investigate their associations with neonatal meconium microbiota.

METHODS

A total of 465 pregnant women reported their stress conditions, including depression, anxiety, pregnancy-related anxiety, perceived stress, sleep, fear of birth, life events, and adverse childhood experiences. Meconium samples were collected from 348 newborns. Latent class analysis was used to identify the patterns of maternal stress.

RESULTS

Three group profiles were identified: "high negative emotion," "high ACEs-low negative emotion," and "low stress." the high ACEs-low negative emotion group and low stress group had higher levels of Chao1 diversity than the high negative emotion group (B = 0.25, P < 0.001; B = 0.18, P < 0.001, respectively). The high ACEs-low negative emotion group had higher levels of Chao1 diversity than the low stress group (B = 0.08, P = 0.001). The variations were observed in the abundance of Bacteroidetes, unidentified_Muribaculaceae, unclassified_Lachnospiraceae, unclassified_Clostridiales, unidentified_Bacteroidales, Oscillospira, and Ruminococcus among different maternal stress patterns.

LIMITATIONS

We did not analyze maternal microbiome samples and assessed the gut microbiota at only one time point.

CONCLUSIONS

These findings emphasized the need for a comprehensive approach to prenatal care that extends beyond traditional medical interventions. Addressing maternal stress through targeted support and interventions may help newborns benefit from a more favorable gut microbiota landscape.

The impact of perinatal maternal stress on the maternal and infant gut and human milk microbiomes: A scoping review

BACKGROUND

Perinatal maternal stress, which includes both psychological and physiological stress experienced by healthy women during pregnancy and the postpartum period, is becoming increasingly prevalent. Infant early exposure to adverse environments such as perinatal stress has been shown to increase the long-term risk to metabolic, immunologic and neurobehavioral disorders. Evidence suggests that the human microbiome facilitates the transmission of maternal factors to infants via the vaginal, gut, and human milk microbiomes. The colonization of aberrant microorganisms in the mother's microbiome, influenced by the microbiome-brain-gut axis, may be transferred to infants during a critical early developmental period. This transfer may predispose infants to a more inflammatory-prone microbiome which is associated with dysregulated metabolic process leading to adverse health outcomes. Given the prevalence and potential impact of perinatal stress on maternal and infant health, with no systematic mapping or review of the data to date, the aim of this scoping review is to gather evidence on the relationship between perinatal maternal stress, and the human milk, maternal, and infant gut microbiomes.

METHODS

This is an exploratory mapping scoping review, guided by the Joanna Briggs Institute's methodology along with use of the Prisma Scr reporting guideline. A comprehensive search was conducted using the following databases, CINAHL Complete; MEDLINE; PsycINFO, Web of Science and Scopus with a protocol registered with Open Science Framework DOI 10.17605/OSF.IO/5SRMV.

RESULTS

After screening 1145 papers there were 7 paper that met the inclusion criteria. Statistically significant associations were found in five of the studies which identify higher abundance of potentially pathogenic bacteria such as Erwinia, Serratia, T mayombie, Bacteroides with higher maternal stress, and lower levels of stress linked to potentially beneficial bacteria such Lactococcus, Lactobacillus, Akkermansia. However, one study presents conflicting results where it was reported that higher maternal stress was linked to the prevalence of more beneficial bacteria.

CONCLUSION

This review suggests that maternal stress does have an impact on the alteration of abundance and diversity of influential bacteria in the gut microbiome, however, it can affect colonisation in different ways. These bacterial changes have the capacity to influence long term health and disease. The review analyses data collection tools and methods, offers potential reasons for these findings as well as suggestions for future research.

Risk of developing neuroblastoma influenced by maternal stressful life events during pregnancy and congenital pathologies

OBJECTIVE

A retrospective multicenter study to investigate the potential association between descriptive information related to pregnancy history and perinatal features and the risk of neuroblastoma (NB) in children.

STUDY DESIGN

Data from 56 mothers during 105 pregnancies (56 cases of NB, 49 control siblings) were collected through face-to-face or telephone interviews with mothers of children diagnosed with NB, along with information extracted from Health System databases. Descriptive information related to (a) pregnancy history as maternal stressful life events with perceived distress during pregnancy, weight gain, alcohol and tobacco consumption, mode of delivery and gestational age; and (b) perinatal features as congenital pathologies, weight at birth and type of feeding were examined to identify potential risk factors for NB.

RESULTS

Stressful life events during pregnancy and certain congenital pathologies were independently associated with NB risk. No significant associations were found between other features. Breastfeeding rates were similar between cases and controls.

CONCLUSION

Our results underscore the importance of providing support and care to pregnant women to reduce potential stressors. Further research is needed to better understand the influence of dysbiosis and mitochondrial-nuclear communication impairment as underlying mechanisms of maternal stress during pregnancy and presence of congenital pathologies in order to confirm them as potential risk factors for NB.

Biological, environmental, and psychological stress and the human gut microbiome in healthy adults

Emerging research suggests that the gut microbiome plays a crucial role in stress. We assess stress-microbiome associations in two samples of healthy adults across three stress domains (perceived stress, stressful life events, and biological stress /Respiratory Sinus Arrhythmia; RSA). Study 1 (n = 62; mean-age = 37.3 years; 68% female) and Study 2 (n = 74; mean-age = 41.6 years; female only) measured RSA during laboratory stressors and used 16S rRNA pyrosequencing to classify gut microbial composition from fecal samples. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict functional pathways of metagenomes. Results showed differences in beta diversity between high and low stressful life events groups across both studies. Study 1 revealed differences in beta diversity between high and low RSA groups. In Study 1, the low perceived stress group was higher in alpha diversity than the high perceived stress group. Levels of Clostridium were negatively associated with RSA in Study 1 and levels Escherichia/Shigella were positively associated with perceived stress in Study 2. Associations between microbial functional pathways (L-lysine production and formaldehyde absorption) and RSA are discussed. Findings suggest that certain features of the gut microbiome are differentially associated with each stress domain.

Maternal Prenatal Stress and the Offspring Gut Microbiome: A Cross-Species Systematic Review

The prenatal period is a critical developmental juncture with enduring effects on offspring health trajectories. An individual's gut microbiome is associated with health and developmental outcomes across the lifespan. Prenatal stress can disrupt an infant's microbiome, thereby increasing susceptibility to adverse outcomes. This cross-species systematic review investigates whether maternal prenatal stress affects the offspring's gut microbiome. The study analyzes 19 empirical, peer-reviewed research articles, including humans, rodents, and non-human primates, that included prenatal stress as a primary independent variable and offspring gut microbiome characteristics as an outcome variable. Prenatal stress appeared to correlate with differences in beta diversity and specific microbial taxa, but not alpha diversity. Prenatal stress is positively correlated with Proteobacteria, Bacteroidaceae, Lachnospiraceae, Prevotellaceae, Bacteroides, and Serratia. Negative correlations were observed for Actinobacteria, Enterobacteriaceae, Streptococcaceae, Bifidobacteria, Eggerthella, Parabacteroides, and Streptococcus. Evidence for the direction of association between prenatal stress and Lactobacillus was mixed. The synthesis of findings was limited by differences in study design, operationalization and timing of prenatal stress, timing of infant microbiome sampling, and microbiome analysis methods.

Affective symptoms in pregnancy are associated with the vaginal microbiome

BACKGROUND

Composition of the vaginal microbiome in pregnancy is associated with adverse maternal, obstetric, and child health outcomes. Therefore, identifying sources of individual differences in the vaginal microbiome is of considerable clinical and public health interest. The current study tested the hypothesis that vaginal microbiome composition during pregnancy is associated with an individual's experience of affective symptoms and stress exposure.

METHODS

Data were based on a prospective longitudinal study of a medically healthy community sample of 275 mother-infant pairs. Affective symptoms and stress exposure and select measures of associated biomarkers (diurnal salivary cortisol, serum measures of sex hormones) were collected at each trimester; self-report, clinical, and medical records were used to collect detailed data on socio-demographic factors and health behavior, including diet and sleep. Vaginal microbiome samples were collected in the third trimester (34-40 weeks) and characterized by 16S rRNA sequencing. Identified taxa were clustered into three community clusters (CC1-3) based on dissimilarity of vaginal microbiota composition.

RESULTS

Results indicate that depressive symptoms during pregnancy were reliably associated with individual taxa and CC3 in the third trimester. Prediction of functional potential from 16S taxonomy revealed a differential abundance of metabolic pathways in CC1-3 and individual taxa, including biosynthetic pathways for serotonin and dopamine. We did not find robust evidence linking symptom- and stress-related biomarkers and CCs.

CONCLUSIONS

Our results provide further evidence of how prenatal psychological distress during pregnancy alters the maternal-fetal microbiome ecosystem that may be important for understanding maternal and child health outcomes.

The mediating effect of maternal gut microbiota between prenatal psychological distress and neurodevelopment of infants

BACKGROUND

Prenatal psychological distress and maternal inflammation can increase the risk of neurodevelopmental delay in offspring; recently, the gut microbiota has been shown to may be a potential mechanism behind this association and not fully elucidated in population study.

METHODS

Seventy-two maternal-infant pairs who completed the assessments of prenatal psychological distress during the third trimester and neurodevelopment of infants at age 6-8 months of age were included in this study. The gut microbiota and its short-chain fatty acids (SCFAs) of maternal-infant were determined by 16S rRNA sequencing and liquid chromatography-mass spectrometry analysis. Inflammatory cytokines in the blood of pregnant women during the third trimester were detected by luminex liquid suspension microarrays.

RESULTS

This study found that infants in the prenatal psychological distress group had poorer fine motor skills (β = -4.396, 95 % confidence interval (CI) = -8.546, -0.246, p = 0.038), problem-solving skills (β = -5.198, 95 % CI = -10.358, -0.038, p = 0.048) and total development (β = -22.303, 95%CI = -41.453, -3.153, p = 0.022) compared to the control group. The study also indicated that the higher level of interleukin-1β (IL-1β) (β = -1.951, 95%CI = -3.321, -0.581, p = 0.005) and interferon-inducible protein-10 (IP-10) (β = -0.019, 95%CI = -0.034, -0.004, p = 0.015) during the third trimester, the poorer fine motor skills in infants. Also, the higher level of IL-10 (β = -0.498, 95%CI = -0.862, -0.133, p = 0.007), IL-12p70 (β = -0.113, 95%CI = -0.178, -0.048, p = 0.001), IL-17 A (β = -0.817, 95%CI = -1.517, -0.118, p = 0.022), interferon-γ (β = -0.863, 95%CI = -1.304, -0.422, p < 0.001), IP-10 (β = -0.020, 95%CI = -0.038, -0.001, p = 0.035), and regulated upon activation normal T cell expressed and secreted (β = -0.002, 95%CI = -0.003, -0.001, p = 0.005) during the third trimester, the poorer problem-solving skills in infants. After controlling for relevant covariates, this study found that maternal gut microbiota Roseburia mediates the relationship between prenatal psychological distress and total neurodevelopment of infants (a = 0.433, 95%CI = 0.079, 0.787, p = 0.017; b = -19.835, 95%CI = -33.877, -5.792, p = 0.006; c = 22.407, 95%CI = -43.207,-1.608, p = 0.035; indirect effect = -8.584, 95%CI = -21.227, -0.587).

CONCLUSIONS

This is the first study to emphasize the role of the maternal-infant gut microbiota in prenatal psychological distress and infant neurodevelopment. Further studies are needed to explore the biological mechanisms underlying the relationship between prenatal psychological distress, maternal-infant gut microbiota, and infant neurodevelopment.

The Microbiota-Gut-Brain Axis and Neurological Disorders: A Comprehensive Review

Microbes have inhabited the earth for hundreds of millions of years longer than humans. The microbiota-gut-brain axis (MGBA) represents a bidirectional communication pathway. These communications occur between the central nervous system (CNS), the enteric nervous system (ENS), and the emotional and cognitive centres of the brain. The field of research on the gut-brain axis has grown significantly during the past two decades. Signalling occurs between the gut microbiota and the brain through the neural, endocrine, immune, and humoral pathways. A substantial body of evidence indicates that the MGBA plays a pivotal role in various neurological diseases. These include Alzheimer's disease (AD), autism spectrum disorder (ASD), Rett syndrome, attention deficit hyperactivity disorder (ADHD), non-Alzheimer's neurodegeneration and dementias, fronto-temporal lobe dementia (FTLD), Wilson-Konovalov disease (WD), multisystem atrophy (MSA), Huntington's chorea (HC), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), temporal lobe epilepsy (TLE), depression, and schizophrenia (SCZ). Furthermore, the bidirectional correlation between therapeutics and the gut-brain axis will be discussed. Conversely, the mood of delivery, exercise, psychotropic agents, stress, and neurologic drugs can influence the MGBA. By understanding the MGBA, it may be possible to facilitate research into microbial-based interventions and therapeutic strategies for neurological diseases.

Social determinants of health, the microbiome, and surgical injury

ABSTRACT

Postinjury infection continues to plague trauma and emergency surgery patients fortunate enough to survive the initial injury. Rapid response systems, massive transfusion protocols, and the development of level 1 trauma centers, among others, have improved the outcome for millions of patients worldwide. Nonetheless, despite this excellent initial care, patients still remain vulnerable to postinjury infections that can result in organ failure, prolonged critical illness, and even death. While risk factors have been identified (degree of injury, blood loss, time to definitive care, immunocompromise, etc.), they remain probabilistic, not deterministic, and do not explain outcome variability at the individual case level. Here, we assert that analysis of the social determinants of health, as reflected in the patient's microbiome composition (i.e., community structure, membership) and function (metabolomic output), may offer a "window" with which to define individual variability following traumatic injury. Given emerging knowledge in the field, a more comprehensive evaluation of biomarkers within the patient's microbiome, from stool-based microbial metabolites to those in plasma and those present in exhaled breath, when coupled with clinical metadata and machine learning, could lead to a more deterministic assessment of an individual's risk for a poor outcome and those factors that are modifiable. The aim of this piece is to examine how measurable elements of the social determinants of health and the life history of the patient may be buried within the ecologic memory of the gut microbiome. Here we posit that interrogation of the gut microbiome in this manner may be used to inform novel approaches to drive recovery following a surgical injury.

Affective Symptoms in Pregnancy are Associated with the Vaginal Microbiome

Composition of the vaginal microbiome in pregnancy is associated with adverse maternal, obstetric, and child health outcomes. Identifying the sources of individual differences in the vaginal microbiome is therefore of considerable clinical and public health interest. The current study tested the hypothesis that vaginal microbiome composition during pregnancy is associated with an individual's experience of affective symptoms and stress exposure. Data were based on a prospective longitudinal study of a diverse and medically healthy community sample of 275 mother-infant pairs. Affective symptoms and stress exposure and select measures of associated biomarkers (diurnal salivary cortisol, serum measures of sex hormones) were collected at each trimester; self-report, clinical, and medical records were used to collect detailed data on socio-demographic factors and health behavior, including diet and sleep. Vaginal microbiome samples were collected in the third trimester (34-40 weeks) and characterized by 16S rRNA sequencing. Identified taxa were clustered into three community state types (CST1-3) based on dissimilarity of vaginal microbiota composition. Results indicate that depressive symptoms during pregnancy were reliably associated with individual taxa and CST3 in the third trimester. Prediction of functional potential from 16S taxonomy revealed a differential abundance of metabolic pathways in CST1-3 and individual taxa, including biosynthetic pathways for the neuroactive metabolites, serotonin and dopamine. With the exception of bioavailable testosterone, no significant associations were found between symptoms- and stress-related biomarkers and CSTs. Our results provide further evidence of how prenatal psychological distress during pregnancy alters the maternal-fetal microbiome ecosystem that may be important for understanding maternal and child health outcomes.

The Maternal Microbiome as a Map to Understanding the Impact of Prenatal Stress on Offspring Psychiatric Health

Stress and psychiatric disorders have been independently associated with disruption of the maternal and offspring microbiome and with increased risk of the offspring developing psychiatric disorders, both in clinical studies and in preclinical studies. However, the role of the microbiome in mediating the effect of prenatal stress on offspring behavior is unclear. While preclinical studies have identified several key mechanisms, clinical studies focusing on mechanisms are limited. In this review, we discuss 3 specific mechanisms by which the microbiome could mediate the effects of prenatal stress: 1) altered production of short-chain fatty acids; 2) disruptions in TH17 (T helper 17) cell differentiation, leading to maternal and fetal immune activation; and 3) perturbation of intestinal and microbial tryptophan metabolism and serotonergic signaling. Finally, we review the existing clinical literature focusing on these mechanisms and highlight the need for additional mechanistic clinical research to better understand the role of the microbiome in the context of prenatal stress.

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.

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.

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.

Maternal stress during the third trimester of pregnancy and the neonatal microbiome

OBJECTIVES

Preliminary research suggests that maternal prenatal stress may alter the development of the fetal microbiome and resulting microbial composition after birth. However, the findings of existing studies are mixed and inconclusive. The purpose of this exploratory study was to assess whether maternal stress during pregnancy is associated with the overall number and diversity of various microbial species in the infant gut microbiome or the abundance of specific bacterial taxa.

METHODS

Fifty-one women were recruited during their third trimester of pregnancy. The women completed a demographic questionnaire and Cohen's Perceived Stress Scale at recruitment. A stool sample was collected from their neonate at one month of age. Data on potential confounders, such as gestational age and mode of delivery, were extracted from medical records to control for their effects. 16s rRNA gene sequencing was used to identify the diversity and abundance of microbial species, along with multiple linear regression models to examine the effects of prenatal stress on microbial diversity. We employed negative binomial generalized linear models to test for differential expression of various microbial taxa among infants exposed to prenatal stress and those not exposed to prenatal stress.

RESULTS

More severe symptoms of prenatal stress were associated with a greater diversity of microbial species in the gut microbiome of neonates (β = .30, p = .025). Certain microbial taxa, such as Lactobacillus and Bifidobacterium, were enriched among infants exposed to greater maternal stress in utero, while others, such as Bacteroides and Enterobacteriaceae, were depleted in contrast to infants exposed to less stress.

CONCLUSIONS

Findings suggest that mild to moderate stress exposure in utero could be associated with a microbial environment in early life that is more optimally prepared to thrive in a stressful postnatal environment. Adaptation of gut microbiota under conditions of stress may involve upregulation of bacterial species, including certain protective microorganisms (e.g. Bifidobacterium), as well as downregulation of potential pathogens (e.g. Bacteroides) via epigenetic or other processes within the fetal/neonatal gut-brain axis. However, further research is needed to understand the trajectory of microbial diversity and composition as infant development proceeds and the ways in which both the structure and function of the neonatal microbiome may mediate the relationship between prenatal stress and health outcomes over time. These studies may eventually yield microbial markers and gene pathways that are biosignatures of risk or resilience and inform targets for probiotics or other therapies in utero or during the postnatal period.

Long-term and trimester-specific effects of prenatal stress on the child gut microbiota

OBJECTIVE

Stress is common among pregnant individuals and is associated with an altered gut microbiota composition in infants. It is unknown if these compositional changes persist into the preschool years when the gut microbiota reaches an adult-like composition. This study aimed to investigate if indicators of prenatal stress (i.e., psychological distress and stress-related physiology) are associated with children's gut microbiota composition and metabolites at 3-4 years of age.

METHODS

Maternal-child pairs (n = 131) were from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort. Each trimester, psychological distress was measured as symptoms of anxiety (Symptom Checklist-90-R) and depressed mood (Edinburgh Postnatal Depression Scale), whereas salivary cortisol was quantified as a measure of stress-related physiology. Child stool samples were collected at 3-4 years to evaluate gut microbiota composition using 16S rRNA gene sequencing and fecal metabolome using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Associations between prenatal distress and cortisol with the gut microbiota were determined using Pearson and Spearman correlations and corrected for multiple testing. Associations between prenatal distress and cortisol with the fecal metabolome were assessed using Metaboanalyst.

RESULTS

Symptoms of depressed mood during the 2nd and 3rd trimesters and anxiety during the 2nd trimester of pregnancy were associated with increased alpha diversity of the child's gut microbiota. Cortisol levels during the 1st trimester were also associated with increased Faith PD diversity (r = 0.32), whereas cortisol levels during the 2nd trimester were associated with reduced Shannon diversity (r = -0.27). Depression scores during the 2nd and 3rd trimesters were associated with reductions in the relative abundances of Eggerthella, Parasutterella, and increases in Ruminococcaceae (rs = -0.28, rs = -0.32, rs = 0.32, respectively), as well as the fecal metabolome (e.g., branched-chain amino acid metabolism). Cortisol levels during the 2nd trimester correlated with 7 bacterial taxa, whereas 1st-trimester cortisol levels were associated with the child's fecal metabolome.

CONCLUSIONS

Prenatal distress and cortisol were associated with both child gut microbiota composition and fecal metabolome at preschool age. Understanding these associations may allow for the identification of microbiota-targeted interventions to support child developmental outcomes affected by prenatal stress.

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.

Infants exposed in utero to Hurricane Maria have gut microbiomes with reduced diversity and altered metabolic capacity

The gut microbiome is a potentially important mechanism that links prenatal disaster exposures with increased disease risks. However, whether prenatal disaster exposures are associated with alterations in the infant's gut microbiome remains unknown. We established a birth cohort study named Hurricane as the Origin of Later Alterations in Microbiome (HOLA) after Hurricane Maria struck Puerto Rico in 2017. We enrolled vaginally born Latino term infants aged 2 to 6 months, including n = 29 infants who were exposed in utero to Hurricane Maria in Puerto Rico and n = 34 infants who were conceived at least 5 months after the hurricane as controls. Shotgun metagenomic sequencing was performed on infant stool swabs. Infants exposed in utero to Hurricane Maria had a reduced diversity in their gut microbiome compared to the control infants, which was mainly seen in the exclusively formula-fed group (P = 0.02). Four bacterial species, including Bacteroides vulgatus, Clostridium innocuum, Bifidobacterium pseudocatenulatum, and Clostridium neonatale, were depleted in the exposure group compared to the control group. Compositional differences in the microbial community and metabolic genes between the exposure and control groups were significant, which were driven by the formula feeding group (P = 0.02 for the microbial community and P = 0.008 for the metabolic genes). Metabolic modules involved in carbohydrate metabolism were reduced in the exposure group. Prenatal maternal exposure to Hurricane Maria was associated with a reduced gut commensal and an altered microbial composition and metabolic potential in the offspring's gut. Breastfeeding can adjust the composition of the gut microbiomes of exposed infants. IMPORTANCE Climate change is a serious issue that is affecting human health. With more frequent and intense weather disasters due to climate change, there is an urgent need to evaluate and understand the impacts of prenatal disaster exposures on the offspring. The prenatal stage is a particularly vulnerable stage for disease origination. However, the impact of prenatal weather disaster exposures on the offspring's gut microbiome has not been evaluated. Our HOLA study starts to fill this knowledge gap and provides novel insights into the microbiome as a mechanism that links prenatal disaster exposures with elevated disease risks. Our major finding that reduced microbial diversity and altered metabolic capacity are associated with prenatal hurricane exposures warrants further studies to evaluate the impact of weather disasters on the unborn.

Early life adverse exposures in irritable bowel syndrome: new insights and opportunities

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder worldwide. Extensive research has identified multiple factors contributing to its development, including genetic predisposition, chronic infection, gut dysbiosis, aberrant serotonin metabolism, and brain dysfunction. Recent studies have emphasized the critical role of the early life stage as a susceptibility window for IBS. Current evidence suggests that diet can heighten the risk of IBS in offspring by influencing the microbiota composition, intestinal epithelium structure, gene expression, and brain-gut axis. The use of antibiotics during pregnancy and the neonatal period disrupts the normal gut microbiota structure, aligning it with the characteristics observed in IBS patients. Additionally, early life stress impacts susceptibility to IBS by modulating TLR4, NK1, and the hypothalamic-pituitary-adrenal (HPA) axis while compromising the offspring's immune system. Formula feeding facilitates the colonization of pathogenic bacteria in the intestines, concurrently reducing the presence of probiotics. This disruption of the Th1 and Th2 cell balance in the immune system weakens the intestinal epithelial barrier. Furthermore, studies suggest that delivery mode influences the occurrence of IBS by altering the composition of gut microbes. This review aims to provide a comprehensive summary of the existing evidence regarding the impact of adverse early life exposures on IBS during pregnancy, intrapartum, and neonatal period. By consolidating this knowledge, the review enhances our understanding of the direct and indirect mechanisms underlying early life-related IBS and offers new insights and research directions from childhood to adulthood.

Multigenerational adversity impacts on human gut microbiome composition and socioemotional functioning in early childhood

Adversity exposures in the prenatal and postnatal period are associated with an increased risk for psychopathology, which can be perpetuated across generations. Nonhuman animal research highlights the gut microbiome as a putative biological mechanism underlying such generational risks. In a sample of 450 mother-child dyads living in Singapore, we examined associations between three distinct adversity exposures experienced across two generations-maternal childhood maltreatment, maternal prenatal anxiety, and second-generation children's exposure to stressful life events-and the gut microbiome composition of second-generation children at 2 y of age. We found distinct differences in gut microbiome profiles linked to each adversity exposure, as well as some nonaffected microbiome features (e.g., beta diversity). Remarkably, some of the microbial taxa associated with concurrent and prospective child socioemotional functioning shared overlapping putative functions with those affected by adversity, suggesting that the intergenerational transmission of adversity may have a lasting impact on children's mental health via alterations to gut microbiome functions. Our findings open up a new avenue of research into the underlying mechanisms of intergenerational transmission of mental health risks and the potential of the gut microbiome as a target for intervention.

Associations of maternal antenatal bonding with neonatal meconium microbiota and the behavior temperament of infants: A prospective longitudinal study

Exposure to a poor intrauterine environment, such as maternal prenatal stress, has been linked to gut microbiota health in infants. Understanding the link between maternal prenatal bonding, early gut microbiota, and neuropsychological development may promote healthy development in early life. This study included 306 mother-child pairs. Women were assessed for maternal antenatal bonding using the Maternal Antenatal Attachment Scale in all three trimesters of pregnancy. Neonatal meconium samples were collected after birth. The behavioral temperament of infants was measured using the Very Short Form of the Infant Behavior Questionnaire-Revised at 6 months postpartum. Maternal prenatal bonding was negatively associated with the infants' relative abundance of Burkholderia and was positively associated with the relative abundance of Bifidobacterium, infant surgency and effortful control. The infant's relative abundance of Burkholderia mediates the association between maternal prenatal bonding and effortful control of the infant. This study provides new evidence about the long-term behavioral implications of a prenatally positive intrauterine environment in offspring microbiomes. The integration of maternal bonding assessment and intervention into prenatal healthcare and wellness models may modulate the establishment of gut microbiota in early life and long-term neuropsychological development in infants.

Prenatal programming of environmental sensitivity

According to several theories, people differ in their sensitivity to environmental influences with some more susceptible than others to both supportive and adverse contextual conditions. Such differences in environmental sensitivity have a genetic basis but are also shaped by environmental factors. Herein we narratively build on our previous work proposing that prenatal experiences contribute to the development of environmental sensitivity. This hypothesis of prenatal programming of postnatal plasticity has considerable empirical support. After presenting illustrative animal and human evidence consistent with this claim, we discuss a range of biological mechanisms likely involved in the pathway from prenatal stress exposure to postnatal environmental sensitivity. We also consider work suggesting that genetic differences, gender, as well as the timing, duration and intensity of prenatal exposures may moderate the effects of prenatal programming on postnatal environmental susceptibility or sensitivity. Before concluding, we highlight "unknowns in the prenatal programming of environmental sensitivity" and their practical implications. Ultimately, we conclude that prenatal stress does not necessarily predispose individuals to problematical development, but rather increases sensitivity to both adverse and supportive postnatal contexts. Thus, prenatal stress may actually foster positive development if paired with supportive and caring postnatal environments.

Role of Inflammaging on the Reproductive Function and Pregnancy

During female lifetime and pregnancy, inflammation and cellular senescence are implicated in physiological processes, from ovulation and menstruation, to placental homeostasis and delivery. Several lifestyles, nutritional, and environmental insults, as well as long-lasting pregestational inflammatory diseases may lead to detrimental effects in promoting and sustaining a chronic excessive inflammatory response and inflammaging, which finally contribute to the decay of fertility and pregnancy outcome, with a negative effect on placental function, fetal development, and future health risk profile in the offspring. Maladaptation to pregnancy and obstetric disease may in turn increase maternal inflammaging in a feedback loop, speeding up aging processes and outbreak of chronic diseases. Maternal inflammaging may also impact, through transgenerational effects, on future adult health. Hence, efficacious interventions should be implemented by physicians and healthcare professionals involved in prevention activities to reduce the modifiable factors contributing to the inflammaging process in order to improve public health.

Effects of a maternal mindfulness intervention targeting prenatal psychological distress on infants' meconium microbiota: A randomized controlled trial

BACKGROUND

Maternal psychological distress could affect gut microbiota of the infant; however, previous studies to date have been observational.

OBJECTIVE

To investigate the effects of mindfulness-based intervention (MBI) during pregnancy on the meconium microbiota of infants by alleviating maternal psychological distress.

DESIGN

Randomized controlled trial.

METHOD

Pregnant women with symptoms of depression or anxiety were randomized to either the intervention group (n = 80), comprising usual perinatal care and six digitally guided self-help MBI sessions, or the control group (n = 80) who underwent usual perinatal care. Meconium was collected within 48 h of birth to evaluate the infant's gut microbiota. The Kruskal-Wallis rank sum test, analysis of similarities, and DESeq2 were performed to explore the effects of the MBI on alpha and beta diversity indices and specific genera.

RESULTS

There were no significant differences between groups regarding the alpha diversity indices, including Chao1 and Simpson (p = 0.83 and p = 0.58). However, there was a significant between-group difference in the beta diversity index (R=0.02, p = 0.03). Bifidobacterium (log2 fold change=-1.90, FDR=0.002) and Blautia (log2 fold change=-1.45, FDR=0.01) were abundant in the intervention group, whereas Staphylococcus (log2 fold change=1.44, FDR=0.01) was abundant in the control group.

CONCLUSIONS

MBI aimed at alleviating maternal psychological distress can positively alter the meconium microbiota of infants. However, the mechanisms underlying the effects of maternal mindfulness during pregnancy on infant meconium microbiota require further exploration.

Associations of maternal prenatal emotional symptoms with neurodevelopment of children and the neonatal meconium microbiota: A prospective cohort study

BACKGROUND

Maternal emotional symptoms during pregnancy increase the risk of neurodevelopmental problems in offspring, and microbiota have been shown to be a potential mechanism underlying the link. However, the associations among maternal prenatal emotional symptoms, the meconium microbiota, and offspring neurodevelopment have yet to be fully elucidated. The aim of this prospective cohort study was to assess the relationship between maternal prenatal emotional symptoms and neurodevelopment of the child at 24 months of age, and to investigate the potential role of the neonatal meconium microbiota in the relationship.

METHODS

A total of 410 mother-child pairs (152 women in the Symptoms group vs. 258 women in the No-symptoms group) were recruited from the ongoing Shanghai Maternal-Child Pairs Cohort. This study included a subgroup of women who were assessed for maternal anxiety and depressive symptoms at 32-36 weeks of gestation. Neonatal meconium samples were collected after birth for 16 S sequencing. Children's neurodevelopment was measured using the Ages and Stages Questionnaire, Third Edition (ASQ-3) and Strengths and Difficulties Questionnaire (SDQ) at 24 months postnatally (n = 287).

RESULTS

Compared with the No-symptoms group, children in the Symptoms group had a higher degree of hyperactivity and total difficulties at 24 months of age. Increases in alpha diversity, distinct overall composition, enriched relative abundance of Proteobacteria, and different predicted microbial functions were observed in the meconium of neonates exposed to maternal prenatal emotional symptoms. The neonatal gut microbiota alpha diversity and relative abundance of genera from the Proteobacteria phylum and Lactobacillus were negatively correlated with children's degree of prosocial behavior, tendency toward hyperactivity, and poor fine motor development. In addition, mediating effects of neonatal meconium microbial richness and the relative abundance of Lactobacillus were observed between maternal emotional symptoms and children's prosocial behavior.

CONCLUSIONS

Maternal prenatal emotional symptoms are associated with alterations in the offspring meconium microbiota and children's neurodevelopment at 24 months of age, and the microbial richness indices and Lactobacillus may play a mediating role. Future research is needed to identify and understand the biological pathways and metabolisms linking the relationships among maternal emotional symptoms, meconium microbiota, and neurodevelopment of children.

Differences in gut microbiota correlate with symptoms and regional brain volumes in patients with late-life depression

Depression is associated with gut dysbiosis that disrupts a gut-brain bidirectional axis. Gray matter volume changes in cortical and subcortical structures, including prefrontal regions and the hippocampus, have also been noted in depressive disorders. However, the link between gut microbiota and brain structures in depressed patients remains elusive. Neuropsychiatric measures, stool samples, and structural brain images were collected from 36 patients with late-life depression (LLD) and 17 healthy controls. 16S ribosomal RNA (rRNA) gene sequencing was used to profile stool microbial communities for quantitation of microbial composition, abundance, and diversity. T1-weighted brain images were assessed with voxel-based morphometry to detect alterations in gray matter volume between groups. Correlation analysis was performed to identify the possible association between depressive symptoms, brain structures and gut microbiota. We found a significant difference in the gut microbial composition between patients with late-life depression (LLD) and healthy controls. The genera Enterobacter and Burkholderia were positively correlated with depressive symptoms and negatively correlated with brain structural signatures in regions associated with memory, somatosensory integration, and emotional processing/cognition/regulation. Our study purports the microbiota-gut-brain axis as a potential mechanism mediating the symptomatology of LLD patients, which may facilitate the development of therapeutic strategies targeting gut microbes in the treatment of elderly depressed patients.

An Updated Narrative Mini-Review on the Microbiota Changes in Antenatal and Post-Partum Depression

Background: Antenatal depression (AND) and post-partum depression (PPD) are long-term debilitating psychiatric disorders that significantly influence the composition of the gut flora of mothers and infants that starts from the intrauterine life. Not only does bacterial ratio shift impact the immune system, but it also increases the risk of potentially life-threatening disorders. Material and Methods: Therefore, we conducted a narrative mini-review aiming to gather all evidence published between 2018–2022 regarding microflora changes in all three stages of pregnancy. Results: We initially identified 47 potentially eligible studies, from which only 7 strictly report translocations; 3 were conducted on rodent models and 4 on human patients. The remaining studies were divided based on their topic, precisely focused on how probiotics, breastfeeding, diet, antidepressants, exogenous stressors, and plant-derived compounds modulate in a bidirectional way upon behavior and microbiota. Almost imperatively, dysbacteriosis cause cognitive impairments, reflected by abnormal temperament and personality traits that last up until 2 years old. Thankfully, a distinct technique that involves fecal matter transfer between individuals has been perfected over the years and was successfully translated into clinical practice. It proved to be a reliable approach in diminishing functional non- and gastrointestinal deficiencies, but a clear link between depressive women’s gastrointestinal/vaginal microbiota and clinical outcomes following reproductive procedures is yet to be established. Another gut-dysbiosis-driving factor is antibiotics, known for their potential to trigger inflammation. Fortunately, the studies conducted on mice that lack microbiota offer, without a shadow of a doubt, insight. Conclusions: It can be concluded that the microbiota is a powerful organ, and its optimum functionality is crucial, likely being the missing puzzle piece in the etiopathogenesis of psychiatric disorders.

Maternal anthropometric variables and clinical factors shape neonatal microbiome

Recent studies indicate the existence of a complex microbiome in the meconium of newborns that plays a key role in regulating many host health-related conditions. However, a high variability between studies has been observed so far. In the present study, the meconium microbiome composition and the predicted microbial metabolic pathways were analysed in a consecutive cohort of 96 full-term newborns. The effect of maternal epidemiological variables on meconium diversity was analysed using regression analysis and PERMANOVA. Meconium microbiome composition mainly included Proteobacteria (30.95%), Bacteroidetes (23.17%) and Firmicutes (17.13%), while for predicted metabolic pathways, the most abundant genes belonged to the class “metabolism”. We observed a significant effect of maternal Rh factor on Shannon and Inverse Simpson indexes (p = 0.045 and p = 0.049 respectively) and a significant effect of delivery mode and maternal antibiotic exposure on Jaccard and Bray–Curtis dissimilarities (p = 0.001 and 0.002 respectively), while gestational age was associated with observed richness and Shannon indexes (p = 0.018 and 0.037 respectively), and Jaccard and Bray–Curtis dissimilarities (p = 0.014 and 0.013 respectively). The association involving maternal Rh phenotype suggests a role for host genetics in shaping meconium microbiome prior to the exposition to the most well-known environmental variables, which will influence microbiome maturation in the newborn.

Prenatal Depression, Breastfeeding, and Infant Gut Microbiota

Depressive symptoms are common during pregnancy and are estimated to affect 7-20% of pregnant women, with higher prevalence found in those with a prior history of depression, in ethnic minorities, and those with increased exposure to stressful life events. Maternal depression often remains undiagnosed, and its symptoms can increase adverse health risks to the infant, including impaired cognitive development, behavioral problems, and higher susceptibility to physical illnesses. Accumulating research evidence supports the association between maternal physical health elements to infant gut health, including factors such as mode of delivery, medication, feeding status, and antibiotic use. However, specific maternal prenatal psychosocial factors and their effect on infant gut microbiota and immunity remains an area that is not well understood. This article reviews the literature and supplements it with new findings to show that prenatal depression alters: (i) gut microbial composition in partially and fully formula-fed infants at 3-4 months of age, and (ii) gut immunity (i.e., secretory Immunoglobulin A) in all infants independent of breastfeeding status. Understanding the implications of maternal depression on the infant gut microbiome is important to enhance both maternal and child health and to better inform disease outcomes and management.

Stress gets into the belly: Early life stress and the gut microbiome

Research has established that stress "gets under the skin," impacting neuroendocrine and neuroimmune pathways to influence risk for physical and mental health outcomes. These effects can be particularly significant for early life stress (ELS), or adverse childhood experiences (ACEs). In this review, we explore whether stress gets "into the belly," that is, whether psychosocial stress affects the gut microbiome. We review animal and human research utilizing a variety of stress paradigms (acute laboratory stressors, chronic stress, stressful life events, perceived stress, ELS, in utero stress) and their impacts on the gut microbiota, with a particular focus on ELS. We also review data on dietary interventions to moderate impact of stress on the gut microbiome. Our review suggests strong evidence that acute laboratory stress, chronic stress, and ELS affect the gut microbiota in rodents, and growing evidence that perceived stress and ELS may impact the gut microbiota in humans. Emerging data also suggests, particularly in rodents, that dietary interventions such as omega-3 fatty acids and pre- and pro-biotics may buffer against the effects of stress on the gut microbiome, but more research is needed. In sum, growing evidence suggests that stress impacts not only the neuroendocrine and neuroimmune axes, but also the microbiota-gut-brain-axis, providing a pathway by which stress may get "into the belly" to influence health risk.

Mining microbes for mental health: Determining the role of microbial metabolic pathways in human brain health and disease

There is increasing knowledge regarding the role of the microbiome in modulating the brain and behaviour. Indeed, the actions of microbial metabolites are key for appropriate gut-brain communication in humans. Among these metabolites, short-chain fatty acids, tryptophan, and bile acid metabolites/pathways show strong preclinical evidence for involvement in various aspects of brain function and behaviour. With the identification of neuroactive gut-brain modules, new predictive tools can be applied to existing datasets. We identified 278 studies relating to the human microbiota-gut-brain axis which included sequencing data. This spanned across psychiatric and neurological disorders with a small number also focused on normal behavioural development. With a consistent bioinformatics pipeline, thirty-five of these datasets were reanalysed from publicly available raw sequencing files and the remainder summarised and collated. Among the reanalysed studies, we uncovered evidence of disease-related alterations in microbial metabolic pathways in Alzheimer's Disease, schizophrenia, anxiety and depression. Amongst studies that could not be reanalysed, many sequencing and technical limitations hindered the discovery of specific biomarkers of microbes or metabolites conserved across studies. Future studies are warranted to confirm our findings. We also propose guidelines for future human microbiome analysis to increase reproducibility and consistency within the field.

Maternal Distress and Offspring Neurodevelopment: Challenges and Opportunities for Pre-clinical Research Models

Pre-natal exposure to acute maternal trauma or chronic maternal distress can confer increased risk for psychiatric disorders in later life. Acute maternal trauma is the result of unforeseen environmental or personal catastrophes, while chronic maternal distress is associated with anxiety or depression. Animal studies investigating the effects of pre-natal stress have largely used brief stress exposures during pregnancy to identify critical periods of fetal vulnerability, a paradigm which holds face validity to acute maternal trauma in humans. While understanding these effects is undoubtably important, the literature suggests maternal stress in humans is typically chronic and persistent from pre-conception through gestation. In this review, we provide evidence to this effect and suggest a realignment of current animal models to recapitulate this chronicity. We also consider candidate mediators, moderators and mechanisms of maternal distress, and suggest a wider breadth of research is needed, along with the incorporation of advanced -omics technologies, in order to understand the neurodevelopmental etiology of psychiatric risk.

Polycystic Ovary Syndrome: A Brain Disorder Characterized by Eating Problems Originating during Puberty and Adolescence

Polycystic ovary syndrome (PCOS) is an endocrine condition associated with reproductive and psychiatric disorders, and with obesity. Eating disorders, such as bulimia and recurrent dieting, are also linked to PCOS. They can lead to the epigenetic dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis, thereby impacting on ovarian folliculogenesis. We postulate that PCOS is induced by psychological distress and episodes of overeating and/or dieting during puberty and adolescence, when body dissatisfaction and emotional distress are often present. We propose that upregulated activation of the central HPG axis during this period can be epigenetically altered by psychological stressors and by bulimia/recurrent dieting, which are common during adolescence and which can lead to PCOS. This hypothesis is based on events that occur during a largely neglected stage of female reproductive development. To date, most research into the origins of PCOS has focused on the prenatal induction of this disorder, particularly in utero androgenization and the role of anti-Müllerian hormone. Establishing causality in our peripubertal model requires prospective cohort studies from infancy. Mechanistic studies should consider the role of the gut microbiota in addition to the epigenetic regulation of (neuro) hormones. Finally, clinicians should consider the importance of underlying chronic psychological distress and eating disorders in PCOS.

Pathoetiology and pathophysiology of borderline personality: Role of prenatal factors, gut microbiome, mu- and kappa-opioid receptors in amygdala-PFC interactions

The pathoetiology and pathophysiology of borderline personality disorder (BPD) have been relatively under-explored. Consequently, no targetted pharmaceutical treatments or preventative interventions are available. The current article reviews the available data on the biological underpinnings of BPD, highlighting a role for early developmental processes, including prenatal stress and maternal dysbiosis, in BPD pathoetiology. Such factors are proposed to drive alterations in the infant's gut microbiome, in turn modulating amygdala development and the amygdala's two-way interactions with other brain regions. Alterations in opioidergic activity, including variations in the ratio of the mu-and kappa-opioid receptors seem a significant aspect of BPD pathophysiology, contributing to its comorbidities with depression, anxiety, impulsivity and addiction. Stress and dysphoria are commonly experienced in people classed with BPD. A growing body of data, across a host of medical conditions, indicate that stress and mood dysregulation may be intimately associated with gut dysbiosis and increased gut permeability, coupled to heightened levels of oxidative stress and immune-inflammatory activity. It urgently requires investigation as to the relevance of such gut changes in the course of BPD symptomatology. Accumulating data indicates that BPD symptom exacerbations may be linked to cyclical variations in estrogen, in turn decreasing serotonin and local melatonin synthesis, and thereby overlapping with the pathophysiology of migraine and endometriosis, which also have a heightened association with BPD. Future research directions and treatment implications are indicated.

Annual Research Review: Critical windows - the microbiota-gut-brain axis in neurocognitive development

The gut microbiota is a vast, complex, and fascinating ecosystem of microorganisms that resides in the human gastrointestinal tract. As an integral part of the microbiota-gut-brain axis, it is now being recognized that the microbiota is a modulator of brain and behavior, across species. Intriguingly, periods of change in the microbiota coincide with the development of other body systems and particularly the brain. We hypothesize that these times of parallel development are biologically relevant, corresponding to 'sensitive periods' or 'critical windows' in the development of the microbiota-gut-brain axis. Specifically, signals from the microbiota during these periods are hypothesized to be crucial for establishing appropriate communication along the axis throughout the life span. In other words, the microbiota is hypothesized to act like an expected input to calibrate the development of the microbiota-gut-brain axis. The absence or disruption of the microbiota during specific developmental windows would therefore be expected to have a disproportionate effect on specific functions or potentially for regulation of the system as a whole. Evidence for microbial modulation of neurocognitive development and neurodevelopmental risk is discussed in light of this hypothesis, finishing with a focus on the challenges that lay ahead for the future study of the microbiota-gut-brain axis during development.

Environmental exposures and child and maternal gut microbiota in rural Malawi

BACKGROUND

Gut microbiota composition is associated with child health, but the effect of the environment on microbiota composition is not well understood. Few studies have been conducted in low-income settings where childhood malnutrition is common and possibly related to microbiota composition.

OBJECTIVES

To investigate whether gut microbiota composition in young children and their mothers is associated with different environmental exposures in rural Malawi. We hypothesized that more adverse environmental exposures would be associated with lower levels of microbiota maturity and diversity.

METHODS

Faecal samples from up to 631 children and mothers participating in a nutrition intervention trial were collected at 1, 6, 12, 18, and 30 months (children) and at 1 month (mothers) after birth and analysed for microbiota composition with 16S rRNA sequencing. Bacterial OTU and genus abundances, measures of microbiota maturity and diversity, and UniFrac distances were compared between participants with different environmental exposures. The exposure variables included socio-economic status, water source, sanitary facility, domestic animals, maternal characteristics, season, antibiotic use, and delivery mode.

RESULTS

Measures of microbiota maturity and diversity in children were inversely associated with maternal education at 6, 18, and 30 months and did not otherwise differ consistently between participants with different environmental exposures. Phylogenetic distance was related to season of stool sample collection at all time points. At the level of individual OTUs and genera, season of stool sample collection, type of water source, and maternal education showed most associations with child gut microbiota, while HIV status was the most important predictor of relative OTU and genus abundances in mothers.

CONCLUSION

The results do not support the hypothesis that adverse environmental exposures are broadly associated with lower microbiota maturity and diversity but suggest that environmental exposures influence the abundance of several bacterial OTUs and genera and that low maternal education is associated with higher microbiota maturity and diversity.

Association of maternal prenatal psychological stressors and distress with maternal and early infant faecal bacterial profile

OBJECTIVE

Findings from animal studies indicate that the early gut bacteriome is a potential mechanism linking maternal prenatal stress with health trajectories in offspring. However, clinical studies are scarce and the associations of maternal psychological profiles with the early infant faecal bacteriome are unknown. This study aimed to investigate the associations of prenatal stressors and distress with early infant faecal bacterial profiles in a South African birth cohort study.

METHODS

Associations between prenatal symptoms of depression, distress, intimate partner violence (IPV) and posttraumatic stress disorder (PTSD) and faecal bacterial profiles were evaluated in meconium and subsequent stool specimens from 84 mothers and 101 infants at birth, and longitudinally from a subset of 69 and 36 infants at 4-12 and 20-28 weeks of age, respectively, in a South African birth cohort study.

RESULTS

Infants born to mothers that were exposed to high levels of IPV had significantly higher proportions of Citrobacter and three unclassified genera, all of which belonging to the family Enterobacteriaceae detected at birth. Proportions of these Enterobacteriaceae remained significantly increased over time (birth to 20-28 weeks of life) in infants born to mothers with high levels of IPV exposure compared to infants from mothers with no/low IPV exposure. Infants born to mothers exposed to IPV also had higher proportions of the genus Weissella at 4-12 weeks compared to infants from mothers with no/low IPV exposure. Faecal specimens from mothers exposed to IPV had higher proportions of the family Lactobacillaceae and lower proportions of Peptostreptococcaceae at birth. Maternal psychological distress was associated with decreased proportions of the family Veillonellaceae in infants at 20-28 weeks and a slower decline in Gammaproteobacteria over time. No changes in beta diversity were apparent for maternal or infant faecal bacterial profiles in relation to any of the prenatal measures for psychological adversities.

CONCLUSION

Maternal lifetime IPV and antenatal psychological distress are associated with altered bacterial profiles in infant and maternal faecal bacteria. These findings may provide insights in the involvement of the gut bacteria linking maternal psychological adversity and the maturing infant brain.