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 (≥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 5 and SIBO, we suggest that glucose H 2 /CH 4 breath test may be performed in the subgroup of SSc patients exhibiting GSS ≥5.