Indoor school environments, physical activity, sitting behaviour and pedagogy: a scoping review

Physical activity levels in children are low and sitting time high, despite the health benefits of regular physical activity and limited sitting. Children spend a large proportion of their time at school, hence school-based interventions targeting physical activity and sitting behaviour may be important. Whilst some aspects of school buildings, their layout and furniture may influence children's physical activity and sitting, these effects could be intertwined with pedagogical approaches. This scoping review aims to identify gaps in the research literature regarding the influence of the indoor school environment on pedagogical approaches and on physical activity and sitting. In primary schools, it was found that physical activity can be integrated into lessons with some benefits on academic behaviour and possibly academic performance. Overall, however, the role of the indoor built environment is poorly investigated, although a handful of studies suggest that a radical change in primary school classrooms may increase physical activity and that stand-biased desks may be promising. This study provides a contribution to the emerging research fields of ‘active design’ from the perspective of indoor school design, highlighting a dearth of research, especially on sitting and for secondary education, and a lack of relevant conceptual frameworks

The maternal microbiome during pregnancy and allergic disease in the offspring

There is substantial epidemiological and mechanistic evidence that the increase in allergic disease and asthma in many parts of the world in part relates to changes in microbial exposures and diet acting via the composition and metabolic products of the intestinal microbiome. The majority of research in this field has focused on the gut microbiome during infancy, but it is increasingly clear that the maternal microbiome during pregnancy also has a key role in preventing an allergy-prone immune phenotype in the offspring. The mechanisms by which the maternal microbiome influences the developing fetal immune system include alignment between the maternal and infant regulatory immune status and transplacental passage of microbial metabolites and IgG. Interplay between microbial stimulatory factors such as lipopolysaccharides and regulatory factors such as short-chain fatty acids may also influence on fetal immune development. However, our understanding of these pathways is at an early stage and further mechanistic studies are needed. There are also no data from human studies relating the composition and metabolic activity of the maternal microbiome during pregnancy to the offspring's immune status at birth and risk of allergic disease. Improved knowledge of these pathways may inform novel strategies for tackling the increase in allergic disorders in the modern world

Decreased maternal serum acetate and impaired fetal thymic and regulatory T cell development in preeclampsia

Maternal immune dysregulation seems to affect fetal or postnatal immune development. Preeclampsia is a pregnancy-associated disorder with an immune basis and is linked to atopic disorders in offspring. Here we show reduction of fetal thymic size, altered thymic architecture and reduced fetal thymic regulatory T (Treg) cell output in preeclamptic pregnancies, which persists up to 4 years of age in human offspring. In germ-free mice, fetal thymic CD4+ T cell and Treg cell development are compromised, but rescued by maternal supplementation with the intestinal bacterial metabolite short chain fatty acid (SCFA) acetate, which induces upregulation of the autoimmune regulator (AIRE), known to contribute to Treg cell generation. In our human cohorts, low maternal serum acetate is associated with subsequent preeclampsia, and correlates with serum acetate in the fetus. These findings suggest a potential role of acetate in the pathogenesis of preeclampsia and immune development in offspring