Changes in fecal microbiota with CFTR modulator therapy: A pilot study

•People with CF often have exocrine pancreatic insufficiency (PI) and altered fecal microbiomes.•Whether the PI and resulting nutrient malabsorption causes the fecal dysbiosis is unknown.•In a pilot study, the effects of CFTR modulators on nutrient absorption and dysbiosis depended on whether the recipient was PI or not.•People with PI had trends towards improvement in both.•These findings must be validated in larger studies.