Small intestinal bacterial overgrowth in systemic sclerosis.

OBJECTIVES: The aims of this study were to: (i) determine the prevalence of small intestinal bacterial overgrowth (SIBO) in unselected patients with SSc; (ii) assess both clinical presentation and outcome of SIBO; and (iii) make predictions about which SSc patients are at risk for SIBO.

METHODS: Fifty-one consecutive patients with SSc underwent glucose hydrogen and methane (H(2)/CH(4)) 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 rotating courses of antibiotics (norfloxacin/metronidazole) for 3 months; glucose H(2)/CH(4) breath test was performed at 3-month follow-up.

RESULTS: The prevalence of SIBO was 43.1% 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 (> or =5) and the presence of SIBO (P = 10(-6)); indeed, both sensitivity and specificity of GSS > or =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 > or =5 and SIBO, we suggest that glucose H(2)/CH(4) breath test may be performed in the subgroup of SSc patients exhibiting GSS > or =5.