Brushing teeth in the morning does not usually affect the H. pylori test. Failure to fast, recent history of antibiotic and other medication use, and early retesting of treated individuals can all affect the results. Breath test is the most common method for detecting H. pylori, and there are some things to be aware of before performing the test. 1. Fasting or at least 2 hours of fasting should be completed before the test to avoid stomach contents affecting the test results. 2. Proton pump inhibitors such as rabeprazole and omeprazole should be stopped for at least 2 weeks, bismuth such as colloidal bismuth, antibiotics such as clarithromycin, amoxicillin and other drugs should be stopped for at least 4 weeks, to avoid the influence of such drugs on the activity of Helicobacter pylori. 3. Review of the breath test needs to be performed 1 month after the end of eradication treatment and discontinuation of medication. Because the breath test generally detects H. pylori colonized in the stomach, and generally the behavior of brushing teeth in the morning will not affect the activity of H. pylori in the stomach, so brushing teeth in the morning will not affect the results of the breath test.