The effect of endotoxin on gastrointestinal transit time and intestinal permeability

Acute changes in gastrointestinal transit time, creatinine clearance and dual sugar (lactulose/mannitol) intestinal permeability have been assessed following endotoxin administration ( E. coli 0111:134, phenol extract) to 6 week old rats. Monitoring the progress of orally administered 51Cr-EDTA through the digestive tract showed that, compared to saline injected controls, stomach emptying was considerably delayed in endotoxin treated animals (t 1/2 = 26 ± 2 vs 162 ± 20 min (p < 0.01), but transit time through the small intestine was not significantly altered (81 ± 17 v 93 ± 29 min). Intestinal permeability assessed by the ratio of lactulose to mannitol excretion in urine was higher in endotoxin compared to saline injected rats, 1.01 ± 0.08 vs 0.60 ± 0.04 (p < 0.01). After correcting the individual sugar excretion to take into account the amount of marker available to the small intestine for absorption during the test period, it was concluded that endotoxin treatment was associated with increased lactulose uptake but no change in mannitol absorption. The study also shows that endotoxaemia, uncomplicated by drug administration or other therapeutic manoeuvres, can markedly delay gastric emptying, which is associated with intolerance to oral or nasogastric feeding.