Helicobacter pylori, or Hp for short, is a gram-negative, microaerobic bacterium that grows and multiplies in the human stomach and duodenum. It can cause chronic inflammation of the gastric mucosa, peptic ulcers, and even gastric cancer. It is the only microbial species known to survive in the human stomach. The infection rate of H. pylori is as high as 40-60% in adults and 30-50% in children, which means that one out of 2-3 people is infected. And most people get infected with H. pylori in childhood. What are the symptoms of H. pylori infection? 1, the symptoms caused by H. pylori infection are mainly acid reflux, heartburn, as well as stomach pain and bad breath. This is mainly due to H. pylori induced gastrin secretion, and the occurrence of acid reflux, heartburn, and gastritis, gastric ulcer children, abdominal pain is more obvious, bad breath is one of the most direct germs is H. pylori. 2, Helicobacter pylori can cause chronic gastritis. The main clinical manifestations occur: upper abdominal discomfort, vague pain, sometimes belching, acid reflux, nausea, vomiting symptoms, the course of the disease is slow, easy to recur. 3, for the above symptoms, children infected with H. pylori are more times than children without H. pylori infection. 4, some H. pylori infection does not have particularly obvious symptoms, and the guardian of the family has H. pylori infection, the child has a much greater chance of infection with H. pylori (mainly through the fecal-oral route of transmission). 5, H. pylori can also cause many extra-digestive manifestations, such as growth retardation, anemia, allergic purpura and so on. What are the methods to detect H. pylori? Non-invasive tests include 13C breath test, serum antibody test and stool antigen test; invasive tests include rapid urease test, histology test and Hp culture by gastroscopy. 13C breath test is currently the safest and most convenient detection method, with 90% sensitivity and 100% specificity, and is currently used as the preferred non-invasive test method. Note: Because 14C is radioactive, it is not recommended for children at this time! As long as the child can cooperate with the blowing, the test can be easily completed! Principle of 13C breath test The urease produced by H. pylori breaks down the 13C-labeled urea in the stomach, producing NH3 and 13CO2. 13CO2 is absorbed into the circulation and expelled with exhalation, and the DOB value can be obtained by collecting the exhaled gas and testing for 13CO2 as a basis for diagnosis. Which children need to be tested for H. pylori? Those with repeated episodes of acid reflux, belching, bad breath, bloating, vomiting, abdominal pain, upper abdominal discomfort, and other gastrointestinal symptoms Those with chronic gastritis, peptic ulcer Those with H. pylori infection in first-degree relatives Unexplained growth retardation or refractory iron deficiency anemia Those with gastric mucosa-associated lymphoid tissue (MALT) lymphoma Those who plan to take long-term NSAIDs (including aspirin) After H. pylori eradication Those who are retested.