Prevalence of small intestinal bacterial overgrowth in systemic sclerosis

Objectives: The aims of this study were to find the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with SSc as well as to assess both clinical presentation and outcome of SIBO;
Methods: 101 patients with SSc underwent glucose hydrogen and methane (H2/CH4) breath test. All SSc patients also completed a questionnaire for intestinal symptoms, and a global symptomatic score (GSS) was calculated. SSc patients with SIBO were given course of antibiotic (rifaximin) for 2 weeks; glucose H2/CH4 breath test was performed at 1 month follow-up.
Results: The prevalence of SIBO was 43.4% in our SSc patients. After logistic regression, we identified the following risk factors for SIBO: presence of diarrhoea and constipation. Interestingly, we observed a marked correlation between values of GSS of digestive symptoms (≥5) and the presence of SIBO (P=10-6); indeed, both sensitivity and specificity of GSS ≥5 to predict SIBO were as high as 0.909 and 0.862, respectively. Finally, eradication of SIBO was obtained in 52.4% of the SSc patients with a significant improvement of intestinal symptoms.
Conclusion: Our study underscores that SIBO often occurs in SSc patients. We further suggest that GSS may be systematically performed in SSc patients; since we found a correlation between GSS of digestive symptoms >5 and SIBO, we suggest that glucose H2/CH4 breath test may be performed in the subgroup of SSc patients exhibiting GSS ≥5.