Small intestinal Paneth cells, enteric glial cells (EGC), and goblet cells maintain gut mucosal integrity, homeostasis, and influence host physiology locally and through the gut-brain axis. Little is known about their roles during pregnancy, or how maternal malnutrition impacts these cells and their development. Pregnant mice were fed a control diet (CON), undernourished by 30% vs. control (UN), or fed a high fat diet (HF). At day 18.5 (term = 19), gut integrity and function were assessed by immunohistochemistry and qPCR. UN mothers displayed reduced mRNA expression of Paneth cell antimicrobial peptides (AMP; Lyz2, Reg3g) and an accumulation of villi goblet cells, while HF had reduced Reg3g and mucin (Muc2) mRNA and increased lysozyme protein. UN fetuses had increased mRNA expression of gut transcription factor Sox9, associated with reduced expression of maturation markers (Cdx2, Muc2), and increased expression of tight junctions (TJ; Cldn-7). HF fetuses had increased mRNA expression of EGC markers (S100b, Bfabp, Plp1), AMP (Lyz1, Defa1, Reg3g), and TJ (Cldn-3, Cldn-7), and reduced expression of an AMP-activator (Tlr4). Maternal malnutrition altered expression of genes that maintain maternal gut homeostasis, and altered fetal gut permeability, function, and development. This may have long-term implications for host-microbe interactions, immunity, and offspring gut-brain axis function.

Neighbourhood greenness has been frequently associated with improved mental health in adulthood, yet its impact among youth is less clear. Additionally, though youth spend large portions of time at school, no study has investigated associations between school-based measures of greenness and students’ mental health in Canada. We addressed this gap by linking participant responses from the 2016–2017 Ontario Student Drug Use and Health Survey to school-based features of the built environment. Our analyses included 6313 students, ages 11–20. Measures of greenness were the mean and max of the annual mean Normalized Difference Vegetation Index within 500 m and 1000 m from the centroid of the school postal code. Measures of mental health included: serious psychological distress (Kessler 6-item Psychological Distress Scale), self-rated mental health (using a five-point Likert scale), suicide ideation, and suicide attempt. In our study population, the prevalence of serious psychological distress and low self-rated mental health was 16.7% and 20.3%, respectively. Suicide ideation was reported by 13.5% of participants, while 3.7% reported a suicide attempt. Quantity of greenness was similar between schools in the lower and upper quartiles. In logistic regressions, we found no association between objective school-based greenness and mental health, as assessed by multiple measures, both before and after adjustment. Null findings held true after stratification by season, as well. Whether other characteristics of school greenness (such as type, quality, or access and use) are more impactful to students’ mental health should be a focus of future analyses.

To evaluate current levels of physical activity and sedentary behaviour among pregnant and non-pregnant adults in Canada. We ascertained population-based cross-sectional data from the Canadian Community Health Survey (CCHS), 2015-2019, and the Canadian Health Measures Survey (CHMS), 2007-2019. We included adults who were assigned female at birth and were of reproductive age (aged 18-55 years) living in the provinces. We analyzed activity data from validated questionnaires and accelerometers. We included 53 765 adults from the CCHS and 5321 from the CHMS, weighted to represent 16 million people. Based on accelerometers, both pregnant and non-pregnant adults spent 9.5 hours per day (70% of their time) engaged in sedentary behaviour. Across all survey years, ages, and Canadian regions, pregnant adults, especially those aged under 35 years, spent less time engaged in moderate-to-vigorous physical activity (MVPA) compared with non-pregnant adults. Pregnant adults reported 34.3 minutes (95% CI 30.5-38.2) and objectively accrued 14.9 minutes (95% CI 7.9-21.8) in MVPA per day - 15.1 and 8.9 fewer minutes than non-pregnant adults, respectively. After accounting for self-report bias, only 27.5% (95% CI 24.1-31.0) of the pregnant and 41.1% (95% CI 40.4-41.9) of the non-pregnant adults met the Canadian physical activity guidelines (i.e., ≥150 minutes of MVPA per week). Physical activity levels are remarkably low among both pregnant and non-pregnant adults, with few meeting current guidelines. Given the substantial physical and mental health benefits, more support is needed to increase pre-pregnancy and prenatal activity in Canada.

The Canadian prevalence and incidence of diabetes has increased by the greatest extent in young adulthood. The original Canadian Diabetes Risk Questionnaire (CANRISK) was created to assess dysglycemia risk among adults ≥40 years of age, but it has not been validated among younger adults. Furthermore, it is unclear whether a young adult-specific risk score would better identify dysglycemia in this age group. Analyses were done on participants who completed the self-administered CANRISK and underwent anthropometric and blood glucose measurements, were 18 to 39 years of age, were not pregnant and had no previous diabetes diagnosis. A risk model was generated from a lenient stepwise function fit with predictors identified through univariate analyses. Risk scores were produced from adjusted odds ratios. Model performance was internally validated using bootstrap methods and compared with the original CANRISK prognostic tool. Of the 3,334 participants included in the study, 194 (5.8%) and 51 (1.5%) were living with prediabetes or undiagnosed diabetes, respectively. The model displayed an area under the curve of 73.0%, adjusted to 72.9% after bootstrapping; however, using the original CANRISK model resulted in similar results (area under the curve, 71.4%). Sensitivity and specificity of the new and original models were also comparable (78.8% vs 77.1% and 54.0% vs 55.0%, respectively). The original CANRISK score performed well among young adults, even when compared with a young adult-specific model. We suggest that the cut point be lowered for young adults and the tool be permitted for use in this age group.

Background: Studies suggest maternal weight and weight gain during pregnancy may influence foetal immunological development. However, their role in the aetiology of allergic disease is unclear.Objectives: We sought to examine the impact of maternal pre‐pregnancy body mass index (BMI) and gestational weight gain (GWG) on the incidence of four common paediatric allergic diseases.Methods: We conducted a retrospective, population‐based cohort study of all singleton live births in Ontario, Canada between 2012 and 2014, using maternal‐newborn records from the provincial birth registry linked with health administrative databases. Neonates were followed up to 7 years for anaphylaxis, asthma, dermatitis and rhinitis, identified through validated algorithms based on healthcare encounters. We multiply imputed missing data and employed Cox proportional‐hazards models to calculate adjusted hazard ratios (aHR) with 95% confidence intervals (CI). To test the robustness of our findings, we also conducted several sensitivity analyses, including probabilistic bias analyses for exposure and outcome misclassification. All methods were prespecified in a published protocol.Results: Of the 248,017 infants followed, 52% were born to mothers with a pre‐pregnancy BMI in the normal range and only 19% were born to mothers with adequate weight gain during pregnancy. Incidence rates (per 100,000 person‐days) for anaphylaxis, asthma, dermatitis and rhinitis were 0.22, 6.80, 12.41 and 1.54, respectively. Compared with normal BMI, maternal obesity was associated with increased hazards of asthma in offspring (aHR 1.08, 95% CI 1.05, 1.11), but decreased hazards of anaphylaxis (aHR 0.83, 95% CI 0.69, 0.99) and dermatitis (aHR 0.97, 95% CI 0.94, 0.99). In contrast, maternal underweight was associated with increased hazards of dermatitis (aHR 1.06, 95% CI 1.02, 1.10). We found no associations between pre‐pregnancy BMI and rhinitis or GWG and any allergic outcome, and no evidence of effect measures modification by infant sex.Conclusions: These findings provide support for the involvement of maternal pre‐pregnancy BMI in paediatric allergic disease development.

Small intestinal Paneth cells, enteric glial cells (EGC), and goblet cells maintain gut mucosal integrity, homeostasis, and influence host physiology locally and through the gut-brain axis. Little is known about their roles during pregnancy, or how maternal malnutrition impacts these cells and their development. Pregnant mice were fed a control diet (CON), undernourished by 30% vs. control (UN), or fed a high-fat diet (HF). At day 18.5 (term=19), gut integrity and function were assessed by immunohistochemistry and qPCR. UN mothers displayed reduced mRNA expression of Paneth cell antimicrobial peptides (AMP; Lyz2, Reg3g) and an accumulation of villi goblet cells, while HF had reduced Reg3g and mucin (Muc2) mRNA and increased lysozyme protein. UN fetuses had increased mRNA expression of gut transcription factor Sox9, associated with reduced expression of maturation markers (Cdx2, Muc2), and increased expression of tight junctions (TJ; Cldn-7). HF fetuses had increased mRNA expression of EGC markers (S100b, Bfabp, Plp1), AMP (Lyz1, Defa1, Reg3g), and TJ (Cldn-3, Cldn-7), and reduced expression of an AMP-activator (Tlr4). Maternal malnutrition altered expression of genes that maintain maternal gut homeostasis, and altered fetal gut permeability, function, and development. This may have long-term implications for host-microbe interactions, immunity, and offspring gut-brain axis function.