Background. Available data suggests that small intestine bacterial overgrowth (SIBO) may frequently occur in cystic fibrosis (CF) subjects. SIBO may result in synthesis of enterotoxic and unabsorbable metabolites which may cause mucosal damage and – additionally – interfere with digestion and absorption. Such a relationship was documented in CF mouse model. Therefore, in the present study we aimed to assess the influence of bacterial overgrowth in small intestine in CF patients on lipid digestion and absorption.Material and methods. The study comprised 60 pancreatic insufficient CF patients, 30 children and 30 adults. All enrolled CF subjects were tested for the presence of SIBO using hydrogen/methane breath test with glucose loading. According to the obtained results CF patients were divided into SIBO positive and negative subgroups. Subsequently, 13C-labelled mixed triglyceride breath test was performed to assess lipid digestion and absorption. Cumulative percentage dose recovery (cPDR) was considered to reflect digestion and absorption of lipids.
Results. SIBO was detected in 12 (40.0%) children and 11 (36.7%) adults with CF. The cPDR did not differ between SIBO positive and negative subgroups, neither when assessed separately for children (mean ±SEM: 5.5 ±0.8 vs. 7.4 ±1.0%) and adults (4.9 ±0.8 vs. 7.1 ±0.7%) nor for the entire studied population.
Conclusions. Small intestine bacterial overgrowth does not seem to play a key role in lipid digestion and absorption in cystic fibrosis patients.