In a mouse model of angiotensin II-induced endothelial dysfunction, L. reuteri HY7503 reduced vascular thickening (19.78%), increased serum NO levels (226.70%), upregulated endothelial NO synthase (eNOS) expression in the aortic tissue, and decreased levels of cell adhesion molecules (intercellular adhesion molecule-1 [ICAM-1] and vascular cell adhesion molecule-1 [VCAM-1]) and serum cytokines (tumor necrosis factor-alpha [TNF-α] and interleukin-6 [IL-6]). The gene discussed is NOS3; the disease is endothelial dysfunction.