In this single-arm Phase II study, the investigators will accrue 20 SCD patients who had at least two hospital admissions in the previous 12 months to receive rifaximin 550 mg twice a day for a total of 12 months. The investigators will measure changes in the annual rate of hospital admissions due to vaso-occlusive crisis and the annual rate of hospital days. The investigators will also determine the annual rates of uncomplicated crises and acute chest syndrome. Quality of life due to the disease and to treatment will be determined using a questionnaire. This study will be complemented with exploratory laboratory studies to determine changes in the number of circulating activated neutrophils, intestinal microbiome diversity, urinary 3-indoxyl sulfate levels and serum biomarkers of intestinal permeability (lipopolysaccharides; zonulin, citrulline, and fatty acid binding proteins).
In this single-arm, one-stage Phase II study, the investigators hypothesize that gut decontamination with rifaximin will reduce the frequency of hospital admission due to painful crisis in patients with SCD. The study will accrue 20 SCD patients who had at least two hospital admissions in the previous 12 months. These patients will receive rifaximin 550 mg twice a day for a total of 12 months. This following clinical parameters will be measured: 1. Changes in the annual rate of hospital admissions due to painful crisis; 2. Changes in the annual rate of days hospitalized; 3. Annual rates of uncomplicated crises; 4. Annual rate of acute chest syndrome; 5. Changes in the quality of life; and 6). Toxicities. The following laboratory parameters will be measured: 1. Changes in the number of circulating activated neutrophils; 2. Changes in the intestinal microbiome diversity; 3. Changes in the urinary 3-indoxyl sulfate levels; 4. Changes in the serum biomarkers of intestinal permeability (lipopolysaccharides; zonulin, citrulline, and fatty acid binding proteins).