A pilot study to understand feasibility and acceptability of stool and cord blood sample collection for a large-scale longitudinal birth cohort

Primary succession of Bifidobacteria drives pathogen resistance in neonatal microbiota assembly

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

Peripartum women's perspectives on research study participation in the OneFlorida Clinical Research Consortium during COVID-19 pandemic

Introduction

The COVID-19 pandemic created an unprecedented need for population-level clinical trials focused on the discovery of life-saving therapies and treatments. However, there is limited information on perception of research participation among perinatal populations, a population of particular interest during the pandemic.

Methods

Eligible respondents were 18 years or older, were currently pregnant or had an infant (≤12 months old), and lived in Florida within 50 miles of sites participating in the OneFlorida Clinical Research Consortium. Respondents were recruited via Qualtrics panels between April and September 2020. Respondents completed survey items about barriers and facilitators to participation and answered sociodemographic questions.

Results

Of 533 respondents, most were between 25 and 34 years of age (n = 259, 49%) and identified as White (n = 303, 47%) and non-Hispanic (n = 344, 65%). Facebook was the most popular social media platform among our respondents. The most common barriers to research participation included poor explanation of study goals, discomforts to the infant, and time commitment. Recruitment through healthcare providers was perceived as the best way to learn about clinical research studies. When considering research participation, "myself" had the greatest influence, followed by familial ties. Noninvasive biological samples were highly acceptable. Hispanics had higher positive perspectives on willingness to participate in a randomized study (p = 0.009). Education (p = 0.007) had significant effects on willingness to release personal health information.

Conclusion

When recruiting women during the pregnancy and postpartum periods for perinatal studies, investigators should consider protocols that account for common barriers and preferred study information sources. Social media-based recruitment is worthy of adoption.

Feasibility and acceptability of collecting umbilical cord tissue for prenatal cannabis research: A mixed-methods research study

BACKGROUND

Large-scale longitudinal studies with biological samples are needed to examine the associations between prenatal cannabis use and birth and developmental outcomes.

OBJECTIVES

The aim of this study was to understand the feasibility and acceptability of collecting umbilical cord tissue for the purpose of cannabis use testing in a community sample.

DESIGN

This is a mixed methods research study consisted of a prospective cohort study and a qualitative descriptive study.

METHODS

This study was conducted in Vancouver, British Columbia between January 2021 and August 2022. Participants were recruited during pregnancy, and the umbilical cord tissues were collected at birth and tested for the presence of cannabinoids. After the completion of the study, participants completed an online open-ended questionnaire about their overall experience. Data were analyzed using descriptive and thematic analyses.

RESULTS

Among the 85 eligible individuals, 57 people (67%) consented to the study. The cord tissue was collected for 39 participants (68.4%). The collection rates for participants with vaginal, elective, and emergency cesarean delivery were 73.0%, 71.4%, and 53.8%, respectively, and for those with spontaneous and induced labor were 81.5% and 50%, respectively. Four (7.0%) and seven participants (12.3%) reported prenatal cannabis use in direct and probing self-report questions, respectively. The agreement between any self-report and cord tissue test was moderate (kappa 0.53, 95% confidence interval 0.06-0.99). Qualitative findings were classified into five themes.

CONCLUSION

The collection of cord tissue was perceived acceptable by most participants. Implementation of collection protocols for complex labors, a central hospital unit to liaise direct communications and active participants' involvement might increase the feasibility of future studies.

Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment

PURPOSE

To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study.

METHODS

We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails-hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017.

RESULTS

overall 838 eligible pregnant women were approached. The participation rate was 206(25%) in our study and about 185(90%) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100%),193(93%), 205(99%), and 205(99%), respectively. These values dropped to 65(54%), 83(69%), 84(70%), and 84(70%) for the remaining participants 120(58%) in the third trimester, respectively. Also, we gathered milk samples from 125(60%) of mothers at two to three months after delivery.

CONCLUSION

Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn's urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers.

An Inventory of European Birth Cohorts

Many birth cohorts have been carried out. We performed a review of European birth cohorts to see the countries involved, provide a panorama of the current research topics and design, and, more generally, provide input for those creating collaborations and laying out guidelines aimed at unifying cohort methodologies to enable data merging and maximize knowledge acquisition. We searched PubMed and Embase for articles referring to longitudinal, prospective European birth cohorts and searched online cohort inventories. We found references to 111 birth cohorts, 45 of which began enrolment at birth. These cohorts began between 1921 and 2015 and represented 19 countries, with varying sample sizes (236 to 21,000 children). As of 5 January 2020, were still recruiting. The main areas addressed were allergic diseases (14 cohorts) and environmental exposure (f12 cohorts) and most cohorts were publicly funded. Given the large costs of running cohorts and the importance of long follow-up periods in identifying the risk factors for disorders thought to have a perinatal/early life etiology, current cohorts must be designed to answer research questions considering several aspects, from genetic ones to psychological, social, and environmental ones. Furthermore, universally recognized methodological aspects are needed to permit the comparison and merging of cohort data.

Stunted microbiota and opportunistic pathogen colonization in caesarean-section birth

Immediately after birth, newborn babies experience rapid colonization by microorganisms from their mothers and the surrounding environment1. Diseases in childhood and later in life are potentially mediated by the perturbation of the colonization of the infant gut microbiota2. However, the effects of delivery via caesarean section on the earliest stages of the acquisition and development of the gut microbiota, during the neonatal period (≤1 month), remain controversial3,4. Here we report the disrupted transmission of maternal Bacteroides strains, and high-level colonization by opportunistic pathogens associated with the hospital environment (including Enterococcus, Enterobacter and Klebsiella species), in babies delivered by caesarean section. These effects were also seen, to a lesser extent, in vaginally delivered babies whose mothers underwent antibiotic prophylaxis and in babies who were not breastfed during the neonatal period. We applied longitudinal sampling and whole-genome shotgun metagenomic analysis to 1,679 gut microbiota samples (taken at several time points during the neonatal period, and in infancy) from 596 full-term babies born in UK hospitals; for a subset of these babies, we collected additional matched samples from mothers (175 mothers paired with 178 babies). This analysis demonstrates that the mode of delivery is a significant factor that affects the composition of the gut microbiota throughout the neonatal period, and into infancy. Matched large-scale culturing and whole-genome sequencing of over 800 bacterial strains from these babies identified virulence factors and clinically relevant antimicrobial resistance in opportunistic pathogens that may predispose individuals to opportunistic infections. Our findings highlight the critical role of the local environment in establishing the gut microbiota in very early life, and identify colonization with antimicrobial-resistance-containing opportunistic pathogens as a previously underappreciated risk factor in hospital births.