A healthy gut consists of commensal flora,epithelial layer and gut-associated lymphoid tissue (GALT). GALT is hyporesponsive to commensal flora and dietary antigens,but can recognize and at-tack pathogens. Accumulating evidence suggests that dendritic cells (DCs) play a crucial role in managing this paradoxical situation and maintaining the complex homeostasis in gut. Influenced by intestinal epithelial cells (IECs) and commensal flora,intestinal DCs possess unique properties that enable them to regulate T-helper 2 (Th2) cells,regulatory T cells (Tregs) and immunoglobulin A (IgA)-producing cells in a steady state. During infection,intestinal DCs are involved in the induction of effector lymphocytes, although they are also responsible for initiating pathogenic responses in inflammatory bowel diseases (IBDs). Therefore, intestinal DCs are associated with not only the maintenance of immune tolerance to commensal flora,but also the induction of protective immune responses against pathogens. This review outlines the roles of commensal flora, epithelial layer, and GALT in mucosal homeostasis and inflammation and summarizes recent progress in DCs-mediated intestinal immune homeostasis.

Objective:To investigate the status quo of nursing cognition of caregivers of patients with end-stage renal disease based on cognitive adaptation theory and explore its influencing factors.Methods:The convenient sampling method was adopted to select 150 caregivers of patients with end-stage renal disease admitted to Affiliated Hospital of Jining Medical University from June 2018 to June 2020 as the research objects. Guided by cognitive adaptation theory, a questionnaire was designed to investigate the caregivers' cognitive level of end-stage renal disease care. According to the survey results, caregivers were divided into the high cognition group and the low cognition group. Univariate analysis and Logistic regression analysis were used to analyze the influencing factors of cognitive level of caregivers.Results:There were 150 caregivers in this group, 60 of whom had high nursing cognition, accounting for 40%. There were statistically significant differences between the high cognition group and the low cognition group in knowledge training, life meaning score, internal control scale score and benefit discovery score ( P<0.05) . Logistic regression analysis showed that knowledge training, meaning of life, internal sources of control and the discovery of benefits were the influencing factors for the nursing cognition level of patients with end-stage renal disease ( P<0.05) . Conclusions:The nursing cognition level of caregivers of patients with end-stage renal disease is affected by whether they participate in knowledge training, sense of life meaning, internal control psychological control source and benefit discovery.