CFTR and exocrine pancreatic insufficiency: Ooi et al. identified significant changes in the fecal microbiota and a decrease in fecal calprotectin among individuals with G551D CFTR mutations with ivacaftor treatment [21]; however, other studies, including Ronan et al. examining ivacaftor in individuals with G551D mutations [44] and Pope et al. examining ivacaftor in individuals with R117H mutations and lumacaftor/ivacaftor in individuals with F508del mutations, did not detect significant changes in the fecal microbiome, intestinal inflammation, or pancreatic insufficiency following modulator treatment.