ENVIRONMENTAL FINE PARTICULATE MATTER (PM2.5) AS A DETERMINANT OF GASTRIC MUCOSAL REMODELING: MORPHOLOGICAL MECHANISMS, MICROVASCULAR DYSFUNCTION, AND TRANSLATIONAL IMPLICATIONS

Air pollution has become one of the most significant environmental determinants of global morbidity and mortality. Among atmospheric pollutants, fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5) is considered particularly hazardous due to its high surface reactivity, ability to carry toxic compounds, and capacity to induce systemic biological responses. While the respiratory and cardiovascular consequences of PM2.5 exposure have been extensively investigated, the gastrointestinal tract—particularly the stomach—has received comparatively limited scientific attention despite growing evidence of its vulnerability to environmental pollutants. This study provides a comprehensive analysis of the morphological and pathophysiological effects of PM2.5 exposure on gastric tissues. The objective of this review is to synthesize current experimental, epidemiological, and mechanistic evidence describing how airborne particulate pollutants influence gastric mucosal integrity, inflammatory responses, microcirculatory function, and epithelial regeneration. Particular emphasis is placed on the role of oxidative stress, endothelial dysfunction, systemic inflammatory signaling, and gut barrier disruption as key mechanisms linking air pollution to gastric pathology. Recent experimental models demonstrate that chronic exposure to particulate pollutants may induce structural alterations in gastric tissues including epithelial degeneration, inflammatory infiltration, vascular remodeling, and impaired mucosal regeneration. In addition, morphometric analyses indicate significant changes in mucosal thickness, glandular architecture, and microvascular density. These findings suggest that the stomach represents an important secondary target of environmental toxicants, mediated through both direct and systemic biological pathways. Understanding the morphological consequences of air pollution for gastrointestinal tissues is essential for developing preventive strategies and improving environmental health policies. Future interdisciplinary research integrating environmental toxicology, molecular pathology, and clinical gastroenterology will be crucial for clarifying mechanisms of gastric injury and identifying potential therapeutic targets.