Introduction Small intestinal bacterial overgrowth (SIBO) negatively affects both the structure and function of the small intestine leading to a number of acute and chronic symptoms. The lactulose hydrogen breath test (LHBT) is commonly used to detect SIBO. However, little is known to what extent the diagnosis made by this method can affect the patient’s clinical state.

The aim of this study was to assess whether patients diagnosed with SIBO using LHBT respond clinically to SIBO treatment.

Methods All the patients who were diagnosed with SIBO by LHBT within the last 12 months prior to December 2016 were retrospectively contacted. A visual analogue scale (VAS) on a scale of 0–10 was used to score the severity of their top 3 symptoms pre and post treatment. 0 being the lowest and 10 being the highest severity of each symptom. Positive LHBT was considered as raise of hydrogen >12 ppm against baseline within the first 60 min of the study. A paired t-test was conducted to evaluate the significance of the differences; P value <0.05 was considered as significant.

Results 17 patients were included (10 female, median age 40.5, age range 26–70). All these patients were prescribed antibiotics (AB). Reduction of the symptom 1 and 2 were significant pre vs post treatment but not the symptom 3 (P values respectively: <0.006, <0.009, and <0.1). Comparing the total symptom counts also showed significant reduction in the severity of the symptoms (P <).0001). Analysis of the severity of individual types of symptoms, significant improvement was found in bloating (p < 0.0967), flatulence (p < 0.0247), abdominal discomfort/pain (p < 0.0279) and diarrhoea (p < 0.042).

Conclusion The findings of this study suggest that patients diagnosed with SIBO using LHBT effectively respond to treatment (i.e. AB). Using raise of hydrogen >12 ppm against baseline within the first 60 min of the study is a reliable criteria to diagnose SIBO. Further studies with larger number of patients is required to confirm the findings of this study.

Disclosure of Interest None Declared