Small intestinal permeability and orocaecal transit time in cystic fibrosis.

Cellobiose and mannitol were used as probe molecules to measure intestinal permeability in 36 children with cystic fibrosis, and 25 age matched controls. Orocaecal transit was also evaluated for each subject using the lactulose/hydrogen breath test. There was a fourfold increase in permeability to disaccharide (cellobiose) in patients with cystic fibrosis, but permeability to the monosaccharide (mannitol) was similar to controls. The orocaecal transit time of lactulose was prolonged in patients with cystic fibrosis, but was unrelated to the percentage excretion of cellobiose or mannitol in cystic fibrosis patients or control subjects.