The increasing rate of drug resistance in often leads to eradication failure and the need for rescue therapy, and it is of great significance to explore new rescue therapeutic regimens. In this study, we observed the efficacy of rescue treatment of Helicobacter pylori (H.pylori) with Saccharomyces boulardii (S.boulardii) alone. the primary outcome of the trial was the eradication rate, and the secondary outcome was the incidence of adverse events.

Background: Helicobacter pylori(H.pylori)infection is a common bacterial infection that causes chronic gastritis, peptic ulcer, MALT lymphoma, gastric cancer, and other gastrointestinal diseases. and has been classified as a group 1 biologic carcinogen with a prevalence of about 50% population in china. In recent years, with the massive use of antibiotics, poor patient compliance, and irregular drug use, the side effects associated with drugs have increased and have led to the development of antibiotic-resistant bacteria and a gradual increase in refractory H.pylori infections, researchers have been searching for a safe, effective and simple treatment for H. pylori.

Methods: The patient come from the department of Gastroenterology, Xiangya Third Hospital, Central South University. After obtaining informed consent, patients is randomly divided into a study group and a control group. The study group (n=100) is divided into two stages of treatment, starting with Saccharomyces boulardii monnotherapy for 14 days, Patients who are still positive on reexamination after 4 weeks of stopping the drug continue with bismuth quadruple therapy. As for the control group (n=100), patients is observed for 4 weeks without any gastric drugs as well as antibiotics, and those who were still positive on retest after 4 weeks continued with bismuth quadruple therapy. We observe the eradication rate of patients and the occurrence of adverse effects during the treatment.

Inclusion Criteria:

1. aged 18 to 65 years, of either sex
2. patients with a diagnosis of Hp infection
3. patients who have failed treatment for Hp infection
4. not taking acid-suppressing medications (PPI or H2 blockers) within the last 2 weeks
5. who have not used antibiotics and/or bismuth within the last 4 weeks
6. understand and are willing to participate in this clinical trial and provide a signed informed consent form.

Exclusion Criteria:

1. those with a history of drug allergy
2. those with severe cardiac, hepatic, pulmonary, and renal insufficiencies
3. those with a recent history of gastrointestinal hemorrhage, obstruction, perforation, tumors, and other serious organic diseases of the gastrointestinal tract
4. those with mental illness, psychological disorders that cannot be expressed normally
5. those who are pregnant, lactating, or planning to have children in the near future during the study period.
6. those who are not suitable for clinical trials and those who cannot cooperate