The influence of isolated doses of drugs, feeding and colonic bacterial ureolysis on urea breath test results.
BACKGROUND
Aim of this work was to improve standardization of the 13C-urea breath test (13C-UBT) by evaluating the effect of drug administration, feeding and colonic ureolysis on the UBT results.


METHODS
Three different studies were performed. First, a 13C-UBT was performed in 41 Helicobacter pylori infected subjects before and after 1 day of therapy with sucralfate (5 g), colloidal bismuth (600 mg), amoxycillin (2.5 g) or omeprazole (40 mg). Second, a 13C-UBT was performed in 10 H. pylori-positive patients after an overnight fast and repeated 2 h after lunch. Finally, a 13C-UBT was carried out in seven healthy volunteers, with breath sampling prolonged to 6 h to investigate colonic bacterial ureolysis.


RESULTS
Even a short course of drugs specific for H. pylori may result in a falsely negative 13C-UBT. Feeding does not interfere with the 13C-UBT in infected subjects. No significant 13C-urea breakdown by colonic bacteria is observed during the 13C-UBT when it is prolonged to 6 h.


CONCLUSIONS
The 13C-urea breath test is a sensitive clinical tool for the non-invasive diagnosis of H. pylori infection. It is unaffected by feeding or colonic ureolysis. However, false negative results are likely even after 1 day of therapy with bactericidal, 'cytoprotective' or antisecretory drugs.
Perri
F
F
Department of Medicine, University Hospital Gasthuisberg, Leuven, Belgium.
Maes
B
B
Geypens
B
B
Ghoos
Y
Y
Hiele
M
M
Rutgeerts
P
P
D000328:Adult; D000658:Amoxicillin / Q000627:therapeutic use; D001419:Bacteria / Q000378:metabolism; D001729:Bismuth / Q000627:therapeutic use; D001944:Breath Tests; D003106:Colon / Q000382:microbiology; D004359:Drug Therapy, Combination; D004435:Eating; D005188:False Negative Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000627:therapeutic use; D013392:Sucralfate / Q000627:therapeutic use; D014508:Urea
D013392:Sucralfate; D000658:Amoxicillin; D014508:Urea; D009853:Omeprazole; D001729:Bismuth