Effect of rifaximin on intestinal bacterial overgrowth in Crohn's disease as assessed by the H-2-glucose breath test

The occurrence of intestinal bacterial overgrowth in patients with. Crohn's Disease (CD) has been described and antimicrobial treatment has been shown to be effective in reversing this condition. However, the mechanisms underlying the efficacy of antimicrobial therapy are still only partially known. The aim of the present study was to evaluate the effect afa nan-absorbable antibiotic (rifaximin) in comparison to placebo an bacterial overgrowth in patients with CD. Methods Fourteen patients with inactive CD of the ileum and bacterial overgrowth, as assessed by the hydrogen breath test, were blindly allocated to receive rifaximin (1200 mg/day) or placebo t.i.d. for one week. A hydrogen breath test, and clinical and biochemical parameters were further performed 14 days and 30 days after starting treatment. Results After 14 days, the hydrogen breath test proved to be negative in seven out of seven patients treated with rifaximin (p < 0.05;), and in two out of seven in the placebo group (P = ns). After 30 days, the hydrogen breath test was positive in all patients of rifaximin and placebo group, respectively Na changes in the CDAI scare were documented in any patients. Conclusions Short-term administration of rifaximin is effective in the therapy of bacterial overgrowth in patients with inactive CD of the ileum, thus suggesting that the control of luminal bacterial growth could be useful in the management of these patients. However, since we observed a decline with time in this positive effect,further studies are needed to identify the most appropriate therapeutic strategies.