<abstract> <p>A healthy gastrointestinal tract functions as a highly selective barrier, allowing the absorption of nutrients and metabolites while preventing gut bacteria and other xenobiotic compounds from entering host circulation and tissues. The intestinal epithelium and intestinal mucus provide a physical first line of defense against resident microbes, pathogens and xenotoxic compounds. Prior studies have indicated that the gut microbe <italic>Akkermansia muciniphila</italic>, a mucin-metabolizer, can stimulate intestinal mucin thickness to improve gut barrier integrity. Grape polyphenol (GP) extracts rich in B-type proanthocyanidin (PAC) compounds have been found to increase the relative abundance of <italic>A. muciniphila</italic>, suggesting that PACs alter the gut microbiota to support a healthy gut barrier. To further investigate the effect of GPs on the gut barrier and <italic>A. muciniphila</italic>, male C57BL/6 mice were fed a high-fat diet (HFD) or low-fat diet (LFD) with or without 1% GPs (HFD-GP, LFD-GP) for 12 weeks. Compared to the mice fed unsupplemented diets, GP-supplemented mice showed increased relative abundance of fecal and cecal <italic>A. muciniphila</italic>, a reduction in total bacteria, a diminished colon mucus layer and increased fecal mucus content. GP supplementation also reduced the presence of goblet cells regardless of dietary fat. Compared to the HFD group, ileal gene expression of lipopolysaccharide (LPS)-binding protein (<italic>Lbp</italic>), an acute-phase protein that promotes pro-inflammatory cytokine expression, was reduced in the HFD-GP group, suggesting reduced LPS in circulation. Despite depletion of the colonic mucus layer, markers of inflammation (<italic>Ifng, Il1b, Tnfa, and Nos2</italic>) were similar among the four groups, with the exception that ileal <italic>Il6</italic> mRNA levels were lower in the LFD-GP group compared to the LFD group. Our findings suggest that the GP-induced increase in <italic>A. muciniphila</italic> promotes redistribution of the intestinal mucus layer to the intestinal lumen, and that the GP-induced decrease in total bacteria results in a less inflammatory intestinal milieu.</p> </abstract>

BACKGROUNDResearch suggests that a whole‐school approach to mental health promotion can be more effective than a compartmentalized approach. In particular, student‐led initiatives have demonstrated a positive impact on students' mental health, though not without systemic and individual barriers. Factors that lead to successful implementation and sustaining of student‐led initiatives are currently not well understood. METHODSA case study is presented to demonstrate how a student‐led intervention came about, inspired changes in the school organization and members, and transformed the school's approach to mental health promotion. Analysis of in‐depth interviews with student leaders and adult advisors was informed by theories of innovation diffusion and human motivation. RESULTSKey factors and mechanisms of change were identified for the initiation, transformation, and institutionalization stages of the student‐led initiative. Changes in students' identity and adult advisors' mindset were found to be integral to the successful conversion to a whole‐school approach in mental health promotion. CONCLUSIONSThis study confirms the value of mobilizing the student body as an active resource in promoting mental health in school and the importance of input from school management, advisors, and intervention expert. Recommendations on how to implement a student‐led initiative and sustain the positive changes are given.

No abstract