Non-Helicobacter bacterial flora rarely develops in the gastric mucosal layer of children.

Non-Helicobacter bacteria can be cultured from the gastric mucosa in adults but in children, there are no studies about such microflora. The purpose of this study, therefore, was to clarify whether gastric biota develops in children. In 10 children and 10 adults or elderly (5 H. pylori-infected and 5 uninfected in each group), biopsy specimens of the gastric antrum and corpus and gastric juice were studied for bacterial examinations and the data were compared between both age groups in relation to H. pylori status and luminal pH. Bacterial genera and species were analyzed using both culture and real-time polymerase chain reaction (PCR) with the 52 genus- and species-specific primer sets. Non-Helicobacter bacteria in the mucosa were cultured from all adult patients, whereas microorganisms were cultured in only one child (p < .001). Gastric pH was lower in children (median, 1.4) than in adults (median, 2.6) (p < .005). The grade of endoscopic gastric atrophy was moderate or severe in 8 adults, but absent or mild in all 10 children. Among adults, there was a significant positive correlation between gastric pH and total bacterial counts of both the mucosa and juice. These data indicate that impaired gastric acid secretion associated with long-term H. pylori infection enables non-Helicobacter bacteria to colonize in the human stomach. Such microorganisms rarely colonize in the gastric mucosa in children regardless of H. pylori status.

13C-Urea breath test, using a new compact nondispersive isotope-selective infrared spectrophotometer: comparison with mass spectrometry.

BACKGROUND: The (13)C-urea breath test ((13)C-UBT) is the most commonly used noninvasive method of detecting Helicobacter pylori infection. The isotope ratio mass spectrometer (IRMS) is the most commonly used device for this test, but the UBiT-IR300 infrared spectrophotometer, which, by comparison, is a more compact, less expensive, and easier to use analytical device, has now become widely used in the clinical setting in Japan. The objective of this study was to examine the diagnostic performance of the (13)C-UBT, using the UBiT-IR300. METHODS: A multicenter open-label study was performed, in which the (13)C-UBT was conducted using 100 mg of (13)C-urea. Analysis of (13)CO(2) in the expired breath was performed by infrared spectroscopy and mass spectrometry, and assessment of H. pylori infection was performed by culture, histological examination, and rapid urease test. RESULTS: In 255 cases of H. pylori infection diagnosed by biopsy methods, the (13)C-UBTs, performed with two different (13)C-ruea formulations, and using infrared spectroscopy for evaluation, showed a sensitivity of 97.7%, specificity of 98.0%, and accuracy of 97.8% (total number of evaluable cases, n = 505). The rate of agreement in the assessment of H. pylori infection between infrared spectroscopy and mass spectrometry was 100% ( n = 505). The regression equation for infrared spectroscopy to mass spectrometry was y = 0.9822x - 0.0809 ( n = 2542), with a correlation coefficient of r = 0.99989 ( P = 0.0001). CONCLUSIONS: Diagnosis of H. pylori infection can be performed using infrared spectroscopy as well as mass spectrometry.

Comparison between a new 13C-urea breath test, using a film-coated tablet, and the conventional 13C-urea breath test for the detection of Helicobacter pylori infection.

BACKGROUND: In Japan, urea breath-testing includes mouth rinsing with water immediately after the ingestion of (13)C-urea solution, to prevent false-positive results that are caused by oral bacteria with urease activity. Our objective was to evaluate the diagnostic performance of a urea breath test using a film-coated (13)C-urea tablet and omitting mouth rinsing. METHODS: The study was a multicenter trial comparing the solution- and tablet-based urea breath tests (UBTs). Helicobacter pylori status was determined by histology, culture, and rapid urease testing. RESULTS: Of the 255 subjects who completed the study, evaluation of the tablet-based UBT was possible in 254, and comparison of the tablet-based UBT and the solution-based UBT was possible in 250 patients. When the assessment achieved by a combination of biopsy-based methods was used as a reference standard, the sensitivity, specificity, and accuracy of the tablet-based method were determined to be 97.7%, 98.4%, and 98.0%, respectively. When the results of the solution-based UBT were used as a reference standard, the sensitivity, specificity, and accuracy of the tablet-based UBT were determined to be 96.9%, 97.6%, and 97.2%, respectively. CONCLUSIONS: The (13)C-urea tablet-based method proved to be a simple and accurate test for the diagnosis of H. Pylori infection. Mouth rinsing was not required.