Influence of decontamination of the digestive tract on the urinary excretion of histamine and some of its metabolites.

Urinary excretions of histamine, N tau-methylhistamine and N tau-methylimidazoleacetic acid have been determined for 8 healthy volunteers during 14 consecutive days. Selective decontamination of the digestive tract was performed from day 3 to day 6, followed by total decontamination from day 7 to day 10. Urinary excretions of N tau-methylhistamine and N tau-methylimidazoleacetic acid decreased to a small though significant degree (about 15-20%) after total decontamination, suggesting a histamine production by anaerobic bacteria. Cadaverine decreased for about 70% under both selective and total decontamination, suggesting that this amine in human urine mainly originates from aerobic bacteria in the intestinal tract.