In conclusion, the in vivo experiment results showed that the oral administration of L. reuteri HY7503 improves endothelial dysfunction by suppressing the increase in thickness of blood vessels; these effects are mediated via an increase in NO levels in serum and eNOS expression levels in aorta and the inhibition of the production of inflammatory cytokines (TNF-α and IL-6) and CAMs (ICAM-1 and VCAM-1). The gene discussed is NOS3; the disease is endothelial dysfunction.