Objective — to study the role of Helicobacter pylori (HP) in the development of small intestinal bacterial overgrowth syndrome (SIBO) in residents of the Siberian region, as well as to determine the parameters of the most optimal and affordable method for screening of this pathology. Material and methods. A prospective study has enrolled 205 patients for 2018. Patients were divided into 2 groups depending on the presence or absence of SIBO syndrome: group 1 — 89 (43.4%) patients with SIBO syndrome; group 2 — 116 (56.6%) patients without SIBO syndrome. To conduct a respiratory test, a patient received carbohydrate substrate on an empty stomach. Then, hydrogen and methane concentrations were measured in exhaled air every 15 minutes for the next 90 minutes. Results. A positive result for the presence of HP was obtained in 66 (74.2%) patients of the 1st st group and the 36 (31.0%) patients of the 2nd group (p<0.001). Significant between-group differences were also observed in the quantitative analysis of HP (p<0.001). A negative result for the presence of HP was obtained in 23 (25.8%) patients of the 1st group and 80 (69.0%) patients of the 2nd group. Single HP was found in 31 (34.8%) patients of the 1st group and 20 (17.2%) patients of the 2nd group, moderate amount of HP — in 15 (16.9%) and 8 (6.9%) patients, large amount — in 20 (22.5%) and 8 (6.9%) patients, respectively. Conclusion. Patients with Helicobacter pylori infection are the most susceptible to SIBO syndrome. HP can, directly and indirectly, cause the disease, for example, during the treatment of disease provoked by HP. Gastroesophageal reflux disease and erosive gastritis are associated with the greatest risk because proton pump inhibitors are required in these patients for HP eradication. It should be noted that there is still no highly sensitive available non-invasive method for the diagnosis of SIBO syndrome. Therefore, further searching for the new tests and biomarkers, which would be valuable to diagnose SIBO syndrome, is required.