Gut Microbiota and Immune Mechanisms in Primary Hypertension in Children: A Narrative Review

Primary hypertension (PH) in children is an increasingly prevalent multifactorial disorder involving complex interactions between genetic, metabolic, neurohormonal, immune, and environmental factors. Recent studies highlight the potential role of gut microbiota composition and immune dysregulation in the development and progression of PH and hypertension-mediated organ damage (HMOD) in children. The gut microbiota strongly influences immune responses and vascular function through its metabolites, such as short-chain fatty acids (SCFAs), which help maintain the intestinal barrier and modulate inflammation. Conversely, dysbiosis, defined as reduced microbial diversity and increased proinflammatory taxa, can exacerbate systemic inflammation and hypertension. Immune mechanisms, including T helper 17 (Th17) cell polarization and impaired regulatory T cell (Treg) function, facilitate sodium retention, endothelial dysfunction, and organ remodeling. This narrative review summarizes current knowledge of gut microbiota alterations and immunological pathways in pediatric PH, emphasizing the potential of inflammatory markers as early biomarkers. The review also discusses how lifestyle factors such as diet and physical activity modify the gut microbiota-immune axis and blood pressure regulation. Additionally, the study highlights gaps in current knowledge and possible directions for further research. Understanding these pathways offers promising opportunities for early diagnosis, risk stratification, and novel therapeutic interventions to prevent long-term cardiovascular complications in hypertensive children.