Influence of Helicobacter pylori Infection and Eradication on Small Intestinal Bacterial Overgrowth and Abdominal Symptoms.

BACKGROUND: The relationship between Helicobacter pylori (H. pylori) infection and small intestinal bacterial overgrowth (SIBO) has attracted attention recently.

AIMS: To analyze the influence of H. pylori infection and eradication on SIBO, IMO, and abdominal symptoms.

METHODS: Patients with gastrointestinal symptoms were tested for 13 C urea breath test and if positive, treated with bismuth-based quadruple therapy. Lactulose hydrogen methane breath test (HMBT) was performed and symptoms were assessed using gastrointestinal symptom rating scale (GSRS) before and 6 weeks after eradication.

RESULTS: Of the 102 subjects, 53 were H. pylori positive. The prevalence of SIBO and IMO were higher in patients with H. pylori infection than in those without infection (49.1% vs 24.5%, P = 0.019 for SIBO; 24.5% vs 8.2%, P = 0.027 for IMO). GSRS scores were similar between H. pylori-infected and uninfected patients (2 (IQR: 1;3) vs 2 (IQR: 1;2), P = 0.211). Patients with SIBO or IMO presented higher GSRS scores than patients with both SIBO and IMO negative (2 (IQR: 2;3), 2 (IQR: 2;3) vs 2 (IQR: 1;2), P = 0.011, 0.001, respectively). For the 50 patients who successfully eradicated H. pylori, the response rates for SIBO and IMO were 66.7% and 76.9%, respectively. GSRS scores also significantly decreased (2 (IQR: 1;3) to 0 (IQR: 0;1), P < 0.001) after eradication.

CONCLUSION: Helicobacter pylori infection was associated with higher prevalence of SIBO and IMO, both of which led to more pronounced abdominal symptoms. H. pylori eradication also achieved therapeutic effects on SIBO and IMO, accompanied by relief of abdominal symptoms.