The role of small intestinal bacterial overgrowth in cystic fibrosis: a randomized case-controlled clinical trial with rifaximin.

BACKGROUND: Scientific literature shows a high prevalence of Small Intestinal Bacterial Overgrowth (SIBO) in patients with Cystic Fibrosis (CF). The role of SIBO in nutritional status and gastrointestinal symptoms in CF is not known. Our aim was to study epidemiology and clinical impact of SIBO while assessing the efficacy of rifaximin in eradicating SIBO in CF patients. METHODS: Symptoms questionnaire and Glucose Breath Test (GBT) were given to 79 CF patients (median age 19.6 years; 9.2-36.9). Subjects with a positive GBT were enrolled in a randomized controlled trial and received rifaximin 1200 mg for 14 days or no treatment. Questionnaire and GBT were repeated 1 month after the end of treatment or 45 days after the first negative GBT. RESULTS: Out of 79 patients, 25 were affected by SIBO (31.6%) with a significant correlation with lower BMI, SDS-BMI (p < 0.05) and serum albumin levels (p < 0.05), independently from pancreas insufficiency. Twenty-three patients took part in the randomized trial, 13 patients (56.5%) in rifaximin group and 10 patients (43.5%) in control group. Eradication rate of SIBO was 9/10 (90%) in rifaximin group and 2/6 (33.3%) in control group (p < 0.05). In the rifaximin group, gastrointestinal symptom improvement was observed in 4/5 patients aged ≤ 14 years and in 0/5 patients aged > 14 years (p < 0.05); in 2/6 patients in the control group. CONCLUSIONS: CF patients show a high prevalence of SIBO, related to a poorer nutritional status. Rifaximin therapy is well tolerated and the results are promising in terms of efficacy in eradicating small intestinal bacterial overgrowth in CF.

Slow-release insulin in cystic fibrosis patients with glucose intolerance: a randomized clinical trial.

BACKGROUND: Early stages of glucose metabolism impairment are a period at risk in the long-term prognosis of cystic fibrosis (CF). Slow-release synthetic insulin glargine can be a therapeutic tool in this metabolic condition. METHODS: In this phase 3 multicenter, controlled, two-arm, randomized clinical study, glargine was administered up to a dosage of 0.15 U/kg/die for a period of 18 months. Primary endpoint was the improvement of nutritional status [body mass index (BMI) Z score], while glucose tolerance [hemoglobin A1c (HbA1C) and respiratory function (FEV1 predicted] improvement were the secondary endpoints. RESULTS: Thirty-four subjects (18 in the glargine arm and 16 in the control arm) were evaluated. Adherence to insulin treatment was excellent. No significant adverse events were reported. There were no significant differences in BMI, HbA1C and FEV1 values between the two groups nor within groups, except for HbA1C improvement in the glargine arm at month +18 (p = 0.04). CONCLUSIONS: Glargine treatment was well accepted and tolerated. No real efficacy in improving clinical and glycometabolic conditions was demonstrated. Further studies are necessary to test glargine at higher dosage and for a longer follow-up period.