Gut microbiome in systemic sclerosis: a potential therapeutic target

Introduction
Systemic sclerosis (SSc) is a chronic, connective tissue disease characterized by inflammation, fibrosis and microcirculation disturbances. Gastrointestinal involvement and impaired gut motility observed in SSc promotes the small intestinal bacterial overgrowth (SIBO) defined as the increase in the number of bacteria to over 105 CFU/ml or as the presence of atypical flora.

Aim
To investigate the prevalence and characteristics of SIBO and to assess the efficacy of rifaximin in SIBO treatment in SSc patients.

Material and methods
40 SSc patients and 39 healthy individuals were enrolled in the study. All subjects completed UCLA SCTC GIT 2.0 questionnaire and query for gastrointestinal symptoms. The presence of SIBO was assessed by the lactulose hydrogen breath test (LHBT). Patients with SIBO received 1200 mg rifaximin daily for 10 days. The same diagnostic procedure was performed after completed treatment in order to evaluate SIBO eradication.

Results
The prevalence of SIBO was higher in SSc patients compared with the control group (47.5% vs. 12.8%;p = 0.0008). SIBO eradication after rifaximin treatment was successful in 73.3% of SSc patients.

Conclusions
These data suggest that SIBO occurs more frequently in SSc patients than in controls. Eradication therapy with rifaximin is associated with satisfactory results and a high safety profile.