Objectives: To assess the efficacy of combining unprotected powder enzymes an d oral enteric- coated microsphere (ECM) and to ECM alone in treating nutrient maldigestion in patients with cystic fibrosis. Study design: Patients were rando mly assigned into 2 consecutive, 2- week phases; ECM alone, and ECM plus unprot ected powder enzymes. Fecal fat, energy, and nitrogen output were compared with intake at the end of each phase. Two- tailed, paired t tests were performed to compare outcomes. Results: The mean age of the 14 patients (3 girls) was 5.7 ± 3.2 years (range, 1.9 to 13.4 years). There was no significant difference in pe rcent malabsorption of fat (15.6% vs 18.2% ), energy (13.3% vs 13.4% ), or nitrogen (11.8% vs 11.3% ) between phases. Conclusions: The addition of powd er enzymes to ECM did not improve nutrient maldigestion compared with ECM alone. Objectives: To assess the efficacy of combining unprotected powder enzymes an d oral enteric-coated microsphere (ECM) and to ECM alone in treating nutrient maldigestion in patients with cystic fibrosis. Study design: Patients were rando mly assigned into 2 consecutive, 2-week Both ECM alone, and ECM plus unprot ected powder enzymes. Fecal fat, energy, and nitrogen output were compared with intake at the end of each phase. Two- tailed, paired t tests were performed to compare outcomes. Results: The mean age of the 14 patients (3 girls) was 5.7 ± 3.2 years (range, 1.9 to 13.4 years). There was no significant difference in pe rcent malabsorption of fat (15.6% vs 18.2%), energy (13.3% vs 13.4% or nitrogen (11.8% vs 11.3%) between phases. Conclusions: The addition of powd enzymes to ECM did not improve nutrient maldigestion compared with ECM alone.