A Randomized, Double-Blind, Placebo-Controlled Trial of Rifaximin, a Nonabsorbable Antibiotic, in the Treatment of Tropical Enteropathy

OBJECTIVES: Tropical enteropathy is characterized by an increased urinary lactulose-to-mannitol ( L: M) ratio on a site-specific sugar absorption test and is associated with increased intestinal permeability and decreased nutrient absorptive capacity. The etiology of tropical enteropathy is postulated to be intestinal bacterial overgrowth. This study tested the hypothesis that treatment with a nonabsorbable, broad-spectrum antibiotic, rifaximin, reduces the L: M ratio in rural Malawian children, among whom tropical enteropathy is common. METHODS: All children aged 3-5 years from one village were enrolled in a randomized, double-blind, placebo-controlled trial of treatment with rifaximin for 7 days. The L: M ratio was measured before and after treatment, and the change in the L: M ratio was the primary outcome. Secondary outcomes were changes in the urinary sucrose-to-lactulose (SUC:L) and sucralose-to-lactulose (SCL:L) ratios, as well as changes in the fractions of each test sugar recovered in the urine. RESULTS: A total of 144 children participated in this study, of whom 76% had an elevated L: M ratio on enrollment (L:M >= 0.10). Children who received rifaximin did not show an improvement in their L: M ratio compared with those who received placebo (-0.01 +/- 0.12 vs. 0.02 +/- 0.16, respectively, P=0.51, mean +/- s.d.), nor were there significant differences between the two groups in excretion of lactulose, mannitol, sucralose, or sucrose, or in the SUC:L and SCL:L ratios. CONCLUSIONS: Rifaximin had no effect on the tropical enteropathy of 3-5- year-old Malawian children, suggesting that small-bowel bacterial overgrowth is not an important etiological factor in this condition.