Small Intestinal Bacterial Overgrowth Diagnosed by a Breath Test and Improved by Rifaximin in a Patient with Hepatic Encephalopathy and Alcoholic Liver Cirrhosis.

A 66-year-old Japanese man was admitted to our hospital with grade 2 hepatic encephalopathy (HE). Abdominal computed tomography and laboratory examinations revealed decompensated liver cirrhosis. Intravenous administration of branched-chain amino acids immediately ameliorated the HE, and lactulose was initiated. However, a breath test revealed small intestinal bacterial overgrowth (SIBO); therefore, rifaximin was additionally initiated. The breath test was repeated after discharge, when no evidence of SIBO or overt HE was identified. This case suggested that a breath test is effective for the identification of SIBO and that the administration of a poorly absorbed antibiotic should be considered in SIBO-positive HE patients taking lactulose.

What is the long term acid inhibitor treatment in gastroesophageal reflux disease? What are the potential problems related to long term acid inhibitor treatment in gastroesophageal reflux disease? How should these cases be followed?

The meta-analyses of observational studies (OBS) showed the risk of any fracture and hip fracture slightly increased with proton pump inhibitor (PPI) treatment depending on the dose and regardless of time. This was not observed with histamine-2 receptor antagonists (H2RA). The risk of bacterial overgrowth and spontaneous bacterial peritonitis were increased with PPI therapy, but not with H2RA. In meta-analyses of OBS, a slight increase was observed in the risk of community-acquired pneumonia (CAP) in the early stages (<1 month) of PPI use and particularly at high doses. In a five-year LOTUS study, no difference was found in vitamin B12, folic acid, vitamin D, and calcium values in terms of the initial and end of follow-up levels. No increase in the risk of premalignant gastric lesions was observed in the meta-analysis of RCTs in which PPI treatment (≥6 months) was given to Helicobacter pylori negative patients. The risk of hypomagnesemia with PPI use was increased in patients having GFR<60, using diuretics, and over 65 years of age. Quasi-experimental studies showed a reduced zinc absorption with PPI use. In the meta-analysis of OBS, long-term (>1 year) PPI use increased the risk of fundic polyps, but no risk was found in shorter use. The meta-analyses of RCTS showed no difference between PPI and surgery or placebo arms and between the arms of H2RA and placebo in terms of all side effects. No difference was found between the PPI and H2RA arms both in all and serious adverse effects.

Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study.

AIM: To identify a set of contributors, and weight and rank them on a pathophysiological basis. METHODS: Patients who have undergone a lactulose or glucose hydrogen breath test to rule out small intestinal bacterial overgrowth (SIBO) for various clinical symptoms, including diarrhoea, weight loss, abdominal pain, cramping or bloating, were seen as eligible for inclusion in a retrospective single-centre study. Clinical data such as co-morbidities, medication, laboratory parameters and other possible risk factors have been identified from the electronic data system. Cases lacking or with substantially incomplete clinical data were excluded from the analysis. Suspected contributors were summarised under four different pathophysiological pathways (impaired gastric acid barrier, impaired intestinal clearance, immunosuppression and miscellaneous factors including thyroid gland variables) and investigated using the χ2 test, Student's t-test and logistic regression models. RESULTS: A total of 1809 patients who had undergone hydrogen breath testing were analysed. Impairment of the gastric acid barrier (gastrectomy, odds ratio: OR = 3.5, PPI therapy OR = 1.4), impairment of intestinal clearance (any resecting gastric surgery OR = 2.6, any colonic resection OR = 1.9, stenosis OR = 3.4, gastroparesis OR = 3.4, neuropathy 2.2), immunological factors (any drug-induced immunosuppression OR = 1.8), altered thyroid gland metabolism (hypothyroidism OR = 2.6, levothyroxine therapy OR = 3.0) and diabetes mellitus (OR = 1.9) were associated significantly to SIBO. Any abdominal surgery, ileocecal resection, vagotomy or IgA-deficiency did not have any influence, and a history of appendectomy decreased the risk of SIBO. Multivariate analysis revealed gastric surgery, stenoses, medical immunosuppression and levothyroxine to be the strongest predictors. Levothyroxine therapy was the strongest contributor in a simplified model (OR = 3.0). CONCLUSION: The most important contributors for the development of SIBO in ascending order are immunosuppression, impairment of intestinal clearance and levothyroxine use, but they do not sufficiently explain its emergence.

Short article: Risk of small intestinal bacterial overgrowth with chronic use of proton pump inhibitors in children.

BACKGROUND: Some theorize that prolonged use of proton pump inhibitors (PPIs) may increase the risk of small intestinal bacterial overgrowth (SIBO). Chronic acid suppression and resultant hypochlorhydria may lead to an altered intraluminal environment, which, in turn, may promote the growth of bacteria in the small intestine. A handful of studies measured the risk of SIBO in adults taking PPIs and obtained mixed results; however, this risk has not been exclusively measured in children. AIM: This study aimed to measure the risk of SIBO in children taking PPI versus those not taking PPI. PATIENTS AND METHODS: This was a prospective cohort study. Evaluation of SIBO was performed using the glucose hydrogen breath test. Patients younger than 18 years of age taking a PPI longer than 6 months were compared with healthy control participants. After ingestion of glucose substrate, breath samples were obtained every 15 min for 2 h. An increase in breath hydrogen or methane above 12 ppm was considered diagnostic of SIBO. RESULTS: Overall, 83 participants were tested, of whom 56 were taking PPIs. SIBO was detected in five (8.9%) of the 56 participants taking PPI versus one (3.7%) of the 27 participants in the control group (P=0.359), with a relative risk of 2.4 (95% confidence interval: 0.29-19.6). CONCLUSION: To our knowledge, this is the first study in the English literature measuring the risk of SIBO in children taking PPIs. Our results indicate a potential risk of SIBO in chronic PPI users; however, this is not statistically significant. This is an important finding as PPIs are readily prescribed for children and are often taken longer than 6 months' duration.

Effect of probiotics on small intestinal bacterial overgrowth in patients with gastric and colorectal cancer.

BACKGROUND/AIMS: Small intestinal bacterial overgrowth (SIBO) may be related to the presence of gastrointestinal cancer. The exact link, however, between SIBO and cancer prevalence as well as cancer symptoms remains unclear, especially in Asian populations. In addition, there is a paucity of data documenting the influence of probiotic treatment of SIBO on cancer symptoms. Here, the aims were to correlate the presence of SIBO with cancer prevalence and cancer symptoms, as well as to investigate the effect of probiotic intervention on SIBO and cancer symptoms. MATERIALS AND METHODS: Employing a case-control design, 112 gastric and 88 colorectal cancer patients were evaluated. Questionnaires were used to assess gastrointestinal symptoms and a glucose-H2-breath test (GHBT) was used to determine SIBO status. Patients with SIBO were administered Bifidobacterium triple viable capsule therapy or placebo. Subsequently, SIBO status and gastrointestinal symptom scores were reanalyzed. RESULTS: In our study group, 63.0% of patients versus 16.3% of controls was tested positive for SIBO. In patients with cancer, SIBO was associated with proton pump inhibitor (PPI) use. Bifidobacterium triple viable capsule was effective in combating SIBO and was associated with a significant improvement in gastrointestinal cancer-related symptoms. CONCLUSION: In a Chinese cohort, SIBO is associated with gastrointestinal cancer. Based on the preliminary intervention study, we conclude that probiotic intervention combats SIBO in patients with gastrointestinal cancer and alleviates its symptoms.

Effect of long-term acid gastric inhibition on bacterial translocation in cirrhotic rats.

BACKGROUND: Bacterial translocation (BT) related to intestinal bacterial overgrowth (IBO) plays an important role in the pathogenesis of bacterial infections in cirrhosis. Inhibition of acid gastric secretion promotes IBO and might favor BT. We evaluated the effect of long-term inhibition of acid gastric secretion on BT in cirrhotic rats. METHODS: Cirrhotic rats with and without ascites induced by oral CCl4 and controls were randomized to treatment with a daily subcutaneous injection of placebo, ranitidine (50 mg/kg), or pantoprazole (8 mg/kg) during 2 weeks. Continuous pH-metry was performed for 2 h before and at the end of treatment; thereafter, a laparotomy to obtain samples of blood, mesenteric lymph nodes, ascites, spleen, liver, and cecal stools was performed. RESULTS: Ranitidine and pantoprazole increased gastric pH as compared with placebo (P<0.001). However, antisecretory drugs increased the incidence of BT only in ascitic rats treated with ranitidine (P<0.05) or pantoprazole (P=0.07) when compared with placebo-treated ascitic rats or cirrhotic rats without ascites treated with the same drug. Cirrhotic ascitic rats treated with pantoprazole showed a trend toward an increased incidence of IBO (P=0.08), a higher ileal malondialdehyde level (P<0.01), and an increased production of tumor necrosis factor-α (P<0.05). CONCLUSION: Although inhibition of acid gastric secretion increased gastric pH in all animals, the incidence of BT increased only in ascitic rats, and it was associated with a trend toward an increase in IBO incidence, a higher ileal malondialdehyde level, and an increased production of serum tumor necrosis factor-α. Therefore, antisecretory drugs should be carefully administered to cirrhotic ascitic patients.

Proton pump inhibitor therapy use does not predispose to small intestinal bacterial overgrowth.

OBJECTIVES: Small intestinal bacterial overgrowth (SIBO) occurs due to alteration of the microbiota within the upper gastrointestinal tract. Proton pump inhibitor (PPI) therapy has been suggested as a risk factor for SIBO; however, the published reports have yielded conflicting results on the association between PPI therapy and risk of developing SIBO. The aim of this study was to compare the prevalence of SIBO as measured by glucose hydrogen breath testing (GHBT) in patients on PPI therapy compared with those not on PPI therapy. METHODS: A retrospective chart review was completed for all patients who underwent GHBT testing from 2004 to 2010. Breath samples for hydrogen (H2) and methane (CH4) were collected before and every 20 min for 120 min following ingestion of a 50-g oral glucose load. We used the following criteria to define a positive GHBT (a) increase in H2 > 20 parts per million (p.p.m.) over baseline, (b) sustained rise H2 > 10 p.p.m. over baseline, (c) CH4 > 15 p.p.m. over baseline, and (d) either rise H2 > 20 p.p.m. over baseline or CH4 > 15 p.p.m. RESULTS: A total of 1,191 patients (70% female) were included, of whom 566 (48%) were on PPI therapy. GHBT positivity did not differ significantly between PPI users and nonusers by any of the diagnostic criteria used and PPI use was not significantly associated with GHBT positivity using any of these criteria. GHBT positivity was associated with older age (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.04) and antidiarrheal use (OR 1.99, 95% CI 1.15-3.44) using H2 > 20, older age (OR 1.01, 95% CI 1.00-1.02) and diarrhea (OR 1.53, 95% CI 1.13-2.09) using H2 > 10, and older age (OR 1.01, 95% CI 1.00-1.02) using either H2 > 20 or CH4 > 15. PPI use was not significantly associated with GHBT positivity using any of these criteria. CONCLUSIONS: In this large, adequately powered equivalence study, PPI use was not found to be significantly associated with the presence of SIBO as determined by the GHBT.

Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy.

BACKGROUND & AIMS: Proton pump inhibitors (PPIs) can cause diarrhea, enteric infections, and alter the gastrointestinal bacterial population by suppressing the gastric acid barrier. Among patients that received long term PPI treatment, we evaluated the incidence of small intestinal bacterial overgrowth (SIBO; assessed by glucose hydrogen breath test [GHBT]), the risk factors for development of PPI-related SIBO and its clinical manifestations, and the eradication rate of SIBO after treatment with rifaximin. METHODS: GHBTs were given to 450 consecutive patients (200 with gastroesophageal reflux disease who received PPIs for a median of 36 months; 200 with irritable bowel syndrome [IBS], in absence of PPI treatment for at least 3 years; and 50 healthy control subjects that had not received PPI for at least 10 years). Each subject was given a symptoms questionnaire. RESULTS: SIBO was detected in 50% of patients using PPIs, 24.5% of patients with IBS, and 6% of healthy control subjects; there was a statistically significant difference between patients using PPIs and those with IBS or healthy control subjects (P < .001). The prevalence of SIBO increased after 1 year of treatment with PPI. The eradication rate of SIBO was 87% in the PPI group and 91% in the IBS group. CONCLUSIONS: SIBO, assessed by GHBT, occurs significantly more frequently among long term PPI users than patients with IBS or control subjects. High dose therapy with rifaximin eradicated 87%-91% of cases of SIBO in patients who continued PPI therapy.