Prevalence of Small Intestine Bacterial Overgrowth in Patients With Gastrointestinal Symptoms

Abstract

-Background -Small intestine bacterial overgrowth is a heterogeneous syndrome characterized by an increase in the number and/or the presence of atypical microbiota in the small intestine. The symptoms of small intestine bacterial overgrowth are unspecific, encompassing abdominal pain/distension, diarrhea and flatulence. Due to the increased cost and complexity for carrying out the jejunal aspirate, the gold standard for diagnosis of the syndrome, routinely the hydrogen (H 2 ) breath test has been used, utilizing glucose or lactulose as substrate, which is able to determine, in the exhaled air, the H 2 concentration produced from the intestinal bacterial metabolism. However, due to a number of individuals presenting a methanogenic microbiota, which does not produce H 2 , the testing on devices capable of detecting, concurrently, the concentration of exhaled H 2 and methane (CH 4 ) is justified. Objective -This study aimed to determine the prevalence of small intestine bacterial overgrowth in patients with digestive symptoms, through a comparative analysis of breath tests of H 2 or H 2 and CH 4 associated, using glucose as substrate . Methods -A total of 200 patients of both sexes without age limitation were evaluated, being directed to a Breath Test Laboratory for performing the H 2 test (100 patients) and of exhaled H 2 and CH 4 (100 patients) due to gastrointestinal complaints, most of them patients with gastrointestinal functional disorders. Results -The results indicated a significant prevalence of small intestine bacterial overgrowth in the H 2 test and in the test of exhaled H 2 and CH 4 (56% and 64% respectively) in patients with gastrointestinal symptoms, and higher prevalence in females. It found further that methane gas was alone responsible for positivity in 18% of patients. Conclusion -The data found in this study is consistent with the findings of the current literature and underscores the need for using devices capable of capturing the two gases (exhaled H 2 and CH 4 ) to improve the sensitivity and hence the accuracy of small intestine bacterial overgrowth diagnosis in daily medical practice. HEADINGS -Bacterial growth. Small intestine. Breath tests. Hydrogen. Methane.

Evaluation of lactulose, lactose, and fructose breath testing in clinical practice: A focus on methane

“…This finding, if replicated in another larger cohort, is significant as the rationale for inclusion of methane analysis alongside hydrogen analysis when testing for SIBO or carbohydrate malabsorption is that hydrogen is consumed by archaea, which utilize 4 mol of hydrogen to produce 1 mol of methane. Therefore, when methane is produced, there is likely to be a reduction in hydrogen produced, and including methane in the test will improve its sensitivity …”

“…Therefore, when methane is produced, there is likely to be a reduction in hydrogen produced, and including methane in the test will improve its sensitivity. 15,21,22 While those advocating for the inclusion of methane analysis in the breath test state its value in increasing sensitivity, less consideration has been given to its effect on test specificity, which will likely decrease. In this audit, the variability in methane readings if lactulose was used as a substrate makes it questionable whether a rise in breath methane levels is truly representative of the increased fermentation of the substrate provided or if the rise is independent of ingestion of lactulose.…”

Small Intestinal Bacterial Overgrowth (SIBO): Result of Altered Defensive Mechanism in Gastrointestinal – A Review

“…4,5,7 In an examination with hydrogen breath tests on patients with gastrointestinal symptoms, there is 56% of patients positively diagnosed with SIBO while in a study that was conducted in 2003, there was a prevalence of 66% in the patients with celiac disease. 8,9 In another study with different celiac disease patients, prevalence numbers were resulted differently according to applied examination, including jejunal aspiration and breath test, which found as many as 11% and 23%, respectively. 10 Recently, a meta-analysis study showed that the prevalence of SIBO in the IBS population was 38% dan odds of SIBO were increased 11…”