The main treatment for bad breath caused by H. pylori infection is: 1. Eradication of H. pylori, the main method of which is quadruple therapy containing bismuth, including gastric acid inhibiting drugs such as omeprazole, lansoprazole, pantoprazole as well as esomeprazole, etc.. Gastric mucosal protectors containing bismuth, such as colloidal bismuth pectin and bismuth potassium citrate; and two antibiotics, such as amoxicillin, clarithromycin, metronidazole, and furotoxin. The choice of antibiotics should be used following the advice of a specialist. After one month of taking the drug, half a month after stopping the drug for carbon 14 breath test to detect Helicobacter pylori. 2, maintain oral hygiene, because Helicobacter pylori belongs to the anaerobic bacteria, can survive in the oral cavity of the tooth gap, periodontal pockets, and caries in the tooth. You should remove caries, residual roots, remove tartar, and keep the habit of rinsing your mouth after meals, brushing your teeth in the morning and evening, and use mouthwash to disinfect if necessary.