Abstract :
Background: Glucose and lactulose hydrogen breath tests have been advocated as indirect methods for
identifying patients with small bowel bacterial overgrowth. It is controversy regarding which substrate is better.
Aim: To compare the ability of glucose and lactulose H breath test for identifying abnormal H2 production in the small bowel.
Patients and Methods: Forty-one patients who were suspected of having small bowel bacterial over-
growth underwent 2 H hydrogen breath tests with 50 gm glucose or 10 gm lactulose orally, in random orders, 72 days apart. The glucose or lactulose solution was labeled with 99mTc. A breath sample was obtained at baseline. Then scintigraphic images and breath samples were obtained at time 0 and every 15 min after ingestion of the glucose or lactulose until the radioactive substances reach the cecum. Positive H breath test was defined as an 2 increase of H 10 ppm above baseline before the radioactive substances reach the cecum. Orocecal transit time was 2 the time spent for the radioactive substance to travel from oral cavity to cecum.
Results: All patients completed both breath test studies. Orocecal transit time for glucose was 191 +/- 15
min, significantly longer than lactulose (62 +/- 5 min, p <0.001). Ten and 4 patients had positive glucose and
lactulose H breath test respectively (p = 0.15). One patient had positive of both H breath tests. Thirteen patients 2 2 with positive glucose and lactulose breath test had increase H production begin in the first half of the orocecal 2 transit time, no patient with glucose breath test had positive test begin in the second half of the orocecal transit time. One patient had positive lactulose hydrogen breath test at distal half of small bowel. Patients who had positive at least one breath test had significant longer orocecal transit time of glucose ( 259.5 +/- 16.3 min) and lactulose (105 +/- 6.9 min) compared to patients who had negative results of both breath tests. (169.4 +/- 13.6 min and 57.2 +/- 4.7 min, for glucose and lactulose, respectively, p <0.05)
Conclusions: Glucose H breath test trends to be more sensitive than lactulose breath test for detection
2 of abnormal H production in the small bowel. However, 50 gm glucose breath test could not detect abnormal H2 production in the distal half of the small bowel. Although lactulose breath test could detect abnormal H production in the distal small bowel, it could not identify most patients with positive glucose breath test, supporting the hypothesis that lactulose may not be fermented by gut flora in some patients.
[Thai J Gastroenterol 2006; 7(1): 18-21] |
file/Thai-Journal-of-gastroenterology-vol-7-no-1-3184483.pdf