A single antibiotic may have an effect on the pylorus, mainly in relation to H. pylori infection. H. pylori is a kind of bacteria that often parasitizes the pylorus of human body, and it is the causative agent of many digestive diseases such as gastric erosion, gastric ulcer, duodenal ulcer, gastric cancer and so on. Taking a single antibiotic can kill and inhibit H. pylori initially, but it is generally difficult to completely eradicate H. pylori infection, and resistance will gradually increase with the passage of time, resulting in a decrease in the efficacy of a single antibiotic, which is not conducive to the treatment of H. pylori. Single antibiotic itself for non-allergic and healthy pylorus is not harmful, but long-term use of antibiotics is not conducive to good health, so antibiotics should be used under the guidance of a physician, not blindly self-medication.