Value of the ¹⁴C-<i>D</i>-Xylose Breath Test in Patients with Intestinal Bacterial Overgrowth

Abstract

18 control subjects and 18 patients, with a variety of gastrointestinal conditions were investigated using a 10-μCi ¹⁴C-D-xylose breath test. The latter also underwent quantitative bacterial studies of fluid obtained by intestinal intubation. In 14 patients a smaller dose of 3 μCi ¹⁴C-D-xylose was compared to the standard dose and there was a good correlation between the two doses. The peak value of the ¹⁴C-D-xylose test provided the best discrimination between patients with and without bacterial overgrowth. The ¹⁴C-glycocholic acid test performed in 15 patients, although as sensitive, was less discriminating. The ¹⁴C-D-xylose breath test is reliable and more specific in confirming the diagnosis of small intestinal bacterial overgrowth without having to resort to direct bacterial studies.

Use and abuse of hydrogen breath tests

“…25 88 89 104 In some investigations the 1 g 14 C-Dxylose breath test has shown excellent results but this has not been confirmed in more recent studies. 23 25 104 However, as stated above, the hydrogen breath test with lactulose was found to have both lower specificity and sensitivity than other breath tests.…”

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, THE OBESITY SOCIETY, AND AMERICAN SOCIETY FOR METABOLIC & BARIATRIC SURGERY MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE PERIOPERATIVE NUTRITIONAL, METABOLIC, AND NONSURGICAL SUPPORT OF THE BARIATRIC SURGERY PATIENT

“…Diagnosis can be difficult but should involve upper endoscopy and performance of intestinal aspirate cultures. d ‐Xylose and hydrogen breath tests are available but have limited sensitivity when used alone ( 629 (EL 3), 654 , 655 , 656 , 657 (EL 3)) . Empiric antibiotic therapy, particularly with metronidazole, is usually effective at controlling symptoms and supports the presence of bacterial overgrowth ( 140 (EL 4), 658 (EL 3), 659 (EL 3)) .…”

Using breath tests wisely in a gastroenterology practice: an evidence-based review of indications and pitfalls in interpretation

“…Xylose is predominantly catabolized by gram negatives and, as such, is an excellent substrate for the purposes of breath testing for bacterial overgrowth (100,101). The xylose breath test seems to have a better performance than the tests performed using glucose, lactulose, or bile acids (96,(102)(103)(104)(105)(106). It had a 95% sensitivity and a 100% specificity in one study (107), for diagnosing bacterial overgrowth.…”