Early preschool wheeze trajectories are predominantly non-allergic with distinct biologic and microbiome traits.

Background: Disentangling preschool wheezing heterogeneity in terms of clinical traits, temporal patterns, and collective healthcare burden is critical for precise and effective interventions.

Objective: We aimed to collectively define contributions and distinct characteristics of respiratory phenotypes based on longitudinal wheeze and atopic sensitization patterns in the first 5 years of life.

Methods: Group-based trajectory analysis was performed in the CHILD Cohort study to identify distinct wheeze and allergic sensitization trajectories.

Treatment of Nicotine Use in Adolescents Under 18 Years of Age: An Official American Thoracic Society Clinical Practice Guideline.

The rising popularity of electronic cigarettes (e-cigarettes), the nicotine product that is most used by adolescents since 2014, has reversed decades of progress in declining youth tobacco use. E-cigarette use in adolescents is associated with future smoking, and evidence is mounting of an increased association with nicotine dependence. Therapies used to treat nicotine dependence in adults include pharmacotherapy and behavioral interventions.

Secretory IgA modifies the association between early-life gut microbiota trajectories and childhood nonatopic wheeze.

Aims: Wheezing in childhood is common and evidence is accumulating for the role of the gut microbiome in the development of atopic wheeze. Changes to the early-life gut microbiota and secretory IgA (SIgA) production have been linked to childhood disease; however, their connection to nonatopic wheeze is unknown. The objectives of the present study were to evaluate the relationships between early-life gut microbiota trajectories, SIgA and childhood nonatopic wheeze.

Infant Acid-Suppressant Medication, C. difficile Colonisation, and Childhood Body Mass Index in a Canadian Cohort.

Aim: To determine relationships between paediatric use of acid-suppressive medications (ASMs) (proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA)) and preschool body mass index (BMI) and mediation by C. difficile colonisation.

Methods: ASMs were parent-reported at age 3, 6 and 12 months in 1025 infants from the CHILD Cohort Study.

Human milk IgA promotes normal immune development by limiting Th17-inducing in the infant gut.

The gut microbiota is highly dynamic during the first year of life and plays a crucial role in immune development. Breastfeeding is known to support infant health, but the contributions of the numerous breastmilk components to gut microbiota and immune maturation remain unclear. Secretory IgA (SIgA), the most abundant antibody in human milk, is a key modulator of gut microbiota composition.

Phthalates and bisphenols early-life exposure, and childhood allergic conditions: a pooled analysis of cohort studies.

Background: Exposure to plastic additives, such as phthalates and bisphenols, has been associated with a higher risk of allergic conditions, but the evidence is inconsistent for children younger than five.

Objective: To examine the association between pre- and postnatal urinary phthalates and bisphenols, and allergic conditions, and potential effect modification by sex, in pre-school children, through a pooled analysis.

Methods: We pooled data from the Barwon Infant Study (Australia), the Canadian Healthy Infant Longitudinal Development Study (Canada), the Health Outcomes and Measures of the Environment (United States) and the Environmental Influences on Child Health Outcomes-wide cohorts (United States).

Associations of dietary patterns and obesity development in school-aged children: results from the CHILD Cohort Study.

Objective: We aimed to understand data-driven dietary patterns in Canadian preschoolers and their impact on obesity development among male and female individuals.

Methods: In the prospective, population-based Canadian pregnancy cohort, the CHILD Cohort Study (N = 2219), dietary intake was assessed at age 3 years using a previously developed 112-item food frequency questionnaire. At age 5 years, we measured height, weight, and waist circumference and calculated BMI and waist circumference z scores.

Early life predictors of child development at kindergarten: a structural equation model using a longitudinal cohort.

Introduction: Early child development sets the stage for lifelong health. Identifying early life factors related to child development can help guide programs and policies to bolster child health and wellbeing. The objective of this research was to examine how a broad range of predictors, measured prenatally to the third year of life, are related to child development at kindergarten.

Determining the interplay of prenatal parental BMI in shaping child BMI trajectories: the CHILD Cohort Study.

Background: Obesity is a major public health concern affecting millions of people globally. Early identification of individuals susceptible to obesity is crucial for reducing the burden of obesity. Obesity is often defined based on body-mass-index (BMI), and tracking BMI trajectories from early childhood offers a valuable tool for risk stratification.

Pathogenesis and transmission of SARS-CoV-2 D614G, Alpha, Gamma, Delta, and Omicron variants in golden hamsters.

Since the emergence of SARS-CoV-2 in humans, novel variants have evolved to become dominant circulating lineages. These include D614G (B.1 lineage), Alpha (B.

Relationship between theratyping in nasal epithelial cells and clinical outcomes in people with cystic fibrosis.

Background: In people with cystic fibrosis (pwCF), human nasal epithelial cell (HNEC) cultures can be used to assess response to CF transmembrane conductance regulator (CFTR) modulators. However, thresholds of responses that predict clinical benefit remain poorly understood. In this study we describe the concordance between response in HNECs and clinical outcomes in pwCF harbouring the F508del variant, treated with either lumacaftor/ivacaftor, tezacaftor/ivacaftor or elexacaftor/tezacaftor/ivacaftor.

Gene-by-environment interactions modulate the infant gut microbiota in asthma and atopy.

Background: Gut microbiota has been associated with health and susceptibility to childhood diseases, including asthma and allergies. However, the genomic factors contributing to interindividual variations in gut microbiota remain poorly understood.

Objective: We sought to integrate host genomics with early-life exposures to investigate main and interaction effects on gut microbiota during the first year of life.

The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study: protocol for a prospective, observational cohort study.

Introduction: The rapid growth in popularity of e-cigarettes over the past decade has prompted concerns about their impact on long-term respiratory health. Small airway injury is suspected to be a direct consequence of e-cigarette use and may be quantifiable by novel structural and functional diagnostic modalities.

Methods And Analysis: In a multicentre observational longitudinal study, participants will be enrolled in either an adolescent (ages ≥12 and <19 years) or an adult arm (≥19 years old) and followed over 3 years across three time points (baseline, 18 months and 36 months).

Persistence and decay of neutralizing antibody responses elicited by SARS-CoV-2 infection and hybrid immunity in a Canadian cohort.

Unlabelled: A major challenge with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has been assessing the intensity, dynamics, and determinants of the antibody responses after infection and/or vaccination. Therefore, we aimed to characterize the longitudinal dynamics of the antibody responses among naturally infected individuals and individuals who achieved hybrid immunity in a large Canadian cohort. We demonstrate that anti-Spike IgGs and neutralizing antibody dynamics vary greatly among individuals with COVID-19, in peak antibody levels, rate of waning, and longevity of the antibody response.

Gut microbiota metabolites, secretory immunoglobulin A and Bayley-III cognitive scores in children from the CHILD Cohort Study.

Background: Dysbiosis of the gut microbiota has been demonstrated in neurodevelopmental disorders but the underlying mechanisms that may explain these associations are poorly understood. Gut secretory immunoglobulin A (SIgA) binds pathogenic microbes, preventing mucosal penetration. Gut microbes also influence SIgA production and its binding characteristics through short-chain fatty acid (SCFA) metabolites, allowing them to regulate the immune response.

Exploring the potential mediating role of systemic antibiotics in the association between early-life lower respiratory tract infections and asthma at age 5 in the CHILD study.

Objective: Lower respiratory tract infections (LRTIs) in early life are one of the strongest risk factors for childhood asthma and are often treated with systemic antibiotics (IV or oral). We aimed to explore the association between early-life LRTIs and systemic antibiotics on asthma development and the potential mediating role of antibiotics in this relationship.

Methods: Data were collected as part of the longitudinal, general Canadian population CHILD Study.

Ultraprocessed Food Consumption and Obesity Development in Canadian Children.

Importance: Ultraprocessed foods (UPF), characterized as shelf-stable but nutritionally imbalanced foods, pose a public health crisis worldwide. In adults, UPF consumption is associated with increased obesity risk, but findings among children are inconsistent.

Objectives: To examine the associations among UPF intake, anthropometric adiposity indicators, and obesity status in Canadian children.

Pets and related allergens modify the association between early life DEHP exposure and respiratory outcomes in children.

Introduction: Throughout the perinatal period children are exposed to complex mixtures, including indoor chemicals such as phthalates, and biological agents. However, few studies focus on interactions between early-life co-exposures to shed light on how co-exposures modify their individual effects. Therefore, our study aims to assess whether early-life exposure to pets and related biological agents, namely pet allergens and endotoxin, modifies the association between di-(2-ethylhexyl) phthalate (DEHP) and asthma and wheeze in preschoolers to gain insight into interactions.

Prenatal vitamin C and fish oil supplement use are associated with human milk microbiota composition in the Canadian CHILD Cohort Study.

Maternal diet may modulate human milk microbiota, but the effects of nutritional supplements are unknown. We examined the associations of prenatal diet and supplement use with milk microbiota composition. Mothers reported prenatal diet intake and supplement use using self-administered food frequency and standardised questionnaires, respectively.