Gut bacteria interact directly with colonic mast cells in a humanized mouse model of IBS

Both mast cells and microbiota play important roles in the pathogenesis of Irritable Bowel Syndrome (IBS), however the precise mechanisms are unknown. Using microbiota-humanized IBS mouse model, we show that colonic mast cells and mast cells co-localized with neurons were higher in mice colonized with IBS microbiota compared with those with healthy control (HC) microbiota. In situ hybridization showed presence of IBS, but not control microbiota, in the lamina propria and RNAscope demonstrated frequent co-localization of IBS bacteria and mast cells. TLR4 and H4 receptor expression was higher in mice with IBS microbiota, and in peritoneal-derived and bone marrow-derived mast cells (BMMCs) stimulated with IBS bacterial supernatant, which also increased BMMCs degranulation, chemotaxis, adherence and histamine release. While both TLR4 and H4 receptor inhibitors prevented BMMCs degranulation, only the latter attenuated their chemotaxis. We provide novel insights into the mechanisms, which contribute to gut dysfunction and visceral hypersensitivity in IBS

Experiences of Pediatric Pain Professionals Providing Care during the COVID-19 Pandemic: A Qualitative Study

Chronic pain affects 1 in 5 youth, many of whom manage their pain using a biopsychosocial approach. The COVID-19 pandemic has impacted the way that healthcare is delivered. As part of a larger program of research, this study aimed to understand the impact of the pandemic on pediatric chronic pain care delivery including impact on patients’ outcomes, from the perspective of pediatric healthcare providers. A qualitative descriptive study design was used and 21 healthcare providers from various professional roles, clinical settings, and geographic locations across Canada were interviewed. Using a reflexive thematic analysis approach 3 themes were developed: (1) duality of pandemic impact on youth with chronic pain (i.e., how the pandemic influenced self-management while also exacerbating existing socioeconomic inequalities); (2) changes to the healthcare system and clinical practices (i.e., triaging and access to care); (3) shift to virtual care (i.e., role of institutions and hybrid models of care). These findings outline provider perspectives on the positive and negative impacts of the pandemic on youth with chronic pain and highlight the role of socioeconomic status and access to care in relation to chronic pain management during the pandemic in a high-income country with a publicly funded healthcare system