Clarithromycin combined with tinidazole has a better bacterial clearance effect, and its role in treating Helicobacter pylori is to clean up Helicobacter pylori which induced diseases and then reduce the inflammation, reduce inflammatory factors, and inhibit the increase of COX-2 and Bcl-2 levels caused by inflammatory factors, thus effectively alleviating various symptoms caused by stomach inflammation. The gene discussed is PTGS2; the disease is gastritis.