Predictors Of Small Intestinal Bacterial Overgrowth Research Articles

Prevalence and predictors of small intestinal bacterial overgrowth in systemic sclerosis: a systematic review and meta-analysis.

The reported prevalence of small intestinal bacterial overgrowth (SIBO) among patients with systemic sclerosis (SSc) is highly variable. We conducted this systematic review and meta-analysis to estimate the prevalence and identify predictors of SIBO in SSc by summarizing all of the available data. A comprehensive literature search of the PubMed, Cochrane Library, and EMBASE databases from inception to July 2020 was conducted for studies correlating SIBO with SSc. Studies were screened, and relevant data were extracted and analyzed. The pooled prevalence of SIBO among SSc patients and the odds ratio (OR) of SIBO among SSc patients compared with healthy controls were calculated. Furthermore, predictors of SIBO in SSc were evaluated. Fourteen studies containing 700 SSc patients and 217 healthy controls met the inclusion criteria. The pooled prevalence of SIBO in SSc was 34% (95% CI 27-42%). The OR of SIBO in SSc patients was 12.51 (95% CI 6.51-24.03) compared with the healthy controls. Subgroup analyses showed that the prevalence of SIBO in SSc was higher in studies using the lactulose hydrogen breath test (LHBT) for diagnosis (56%, 95% CI 46-67%) compared with those that used the glucose hydrogen breath test (GHBT) (27%, 95%CI 20-35%) and a jejunal aspirated culture (JAC) (35%, 95%CI 25-51%). The prevalence of SIBO in SSc was higher in studies conducted in Western countries (38%, 95% CI 31-47%) than those conducted in Asian countries (15%, 95%CI 10-23%), and the prevalence of SIBO in the SSc population defined by ACR-EULAR 2013 (50%, 95% CI 0.21-0.79) was higher than the prevalence defined by ACR 1980 (30%, 95% CI 0.17-0.42) or other criteria (32%, 95% CI 0.16-0.48) Moreover, the risk of diarrhea was higher in SSc patients with SIBO than those without SIBO (OR 8.82, 95% CI 4.09-19, P < 0.00001); gender, SSc subset, digital ulcer, and pulmonary fibrosis do not seem to be associated with SIBO in SSc. Antibiotic therapy seems to be effective with SIBO in SSc patients. Approximately one-third of SSc patients tested positive for SIBO with a significantly increased risk over the controls. The prevalence of SIBO in SSc varied according to the SIBO diagnostic test performed, geographic area, and SSc diagnostic criteria. The presence of diarrhea may be a predictor of SIBO in SSc. Antibiotic treatment can lead to eradication of SIBO and gastrointestinal symptomatic improvement in SSc patients. Key Points • The pooled prevalence of SIBO in SSc patients was 34%, which varied according to the SIBO diagnostic test performed, geographic area and SSc diagnostic criteria. • The risk of SIBO in SSc was increased by nearly thirteenfold compared to the healthy controls. • Diarrhoea, but not gender, SSc subset, digital ulcer and pulmonary fibrosis, was associated with SIBO in SSc patients. • For SSc patients with SIBO, antibiotic treatment can lead to eradication of SIBO and gastrointestinal symptomatic improvement.

Serum Gastrin Predicts Hydrogen-Producing Small Intestinal Bacterial Overgrowth in Patients With Abdominal Surgery: A Prospective Study.

OBJECTIVES:Small intestinal bacterial overgrowth (SIBO) might be associated with a history of abdominal surgery. We aimed to evaluate the prevalence of SIBO and to investigate serum gastrin and pepsinogen as predictors of SIBO in patients with a history of hysterectomy, gastrectomy, or cholecystectomy.METHODS:This prospective study surveyed 146 patients with a history of hysterectomy, gastrectomy, or cholecystectomy, and 30 healthy controls, who underwent a hydrogen (H2)-methane (CH4) glucose breath test (GBT) for SIBO. Serum pepsinogen I and II and gastrin levels were reviewed.RESULTS:GBT positivity (+) was significantly higher in patients with histories of abdominal surgery than that in in controls (37.6% vs 13.3%, P < 0.01). Among GBT+ patients, 36.0% (18/50), 96.2% (25/26), and 17.1% (12/70) were in the hysterectomy, gastrectomy, and cholecystectomy groups, respectively. Among the GBT subtypes, 43.6% (24/55), 10.9% (6/55), and 45.5% (25/55) of patients were in the GBT(H2)+, GBT(CH4)+, and GBT(mixed)+ groups, respectively. The gastrectomy group had significantly more GBT+ or GBT(H2)+ patients than the other surgical groups. Gastrin levels were higher in GBT(H2)+ patients and lower in GBT(CH4)+ patients than those in GBT− patients. Previous gastrectomy and elevated gastrin levels were independent predictive factors of GBT(H2)+.DISCUSSION:SIBO is not uncommon in patients with histories of abdominal surgeries, but it is more common in patients who have undergone gastrectomy. Serum gastrin level could be a serologic predictor of H2-producing SIBO. The relationship between serum gastrin and SIBO requires further research.

PREVALENCE AND FACTORS ASSOCIATED WITH SMALL INTESTINAL BACTERIAL OVERGROWTH IN PATIENTS WITH CROHN'S DISEASE: A RETROSPECTIVE STUDY AT A REFERRAL CENTER.

Small intestinal bacterial overgrowth (SIBO) appears to be common in patients with Crohn's disease (CD). The rate of SIBO has been estimated at 25%-88% in this setting. However, different demographic, socioeconomic, and disease-related factors may exist between South American and North American or European populations that may limit the generalization of these findings, as the data are mainly derived from North American or European studies. We studied the prevalence and predictors of SIBO in CD outpatients. In this retrospective study, between June 2011 and June 2016, the medical records of 110 CD patients were assessed for presence of SIBO using the H2/CH4 glucose breath test. Univariate analysis was performed to investigate the potential association between SIBO and demographic, disease-related data, systemic markers of inflammation (C-reactive protein and erythrocyte sedimentation rate). The SIBO rate was high in CD patients (30%). Patients with and without SIBO were comparable according to demographics, systemic inflammatory biomarkers, and disease characteristics, except to the stricturing phenotype more common in the SIBO-positive CD patients (48.5% vs 19.5%, P=0.001). In Brazilian CD patients, SIBO is a highly prevalent condition. Stricturing phenotype demonstrated association with SIBO. An individualized screening plan followed by the timely treatment for SIBO should be carried out as part of quality of care improvement in CD individuals.

Small-Intestinal Bacterial Overgrowth is Associated With Concurrent Intestinal Inflammation But Not With Systemic Inflammation in Crohn's Disease Patients.

We studied the prevalence and predictors of small-intestinal bacterial overgrowth (SIBO) in Crohn's disease (CD) outpatients and the relationship between SIBO and intestinal and/or systemic inflammation. The relationship of SIBO with systemic and intestinal inflammation in CD patients is unclear. In this cross-sectional study, conducted between June, 2013 and January, 2015, 92 CD patients and 97 controls with nonchronic gastrointestinal complaints were assessed for the presence of SIBO using the H2/CH4 glucose breath test. Multivariate logistic regression was performed to investigate the potential association between SIBO and demographic, disease-related data, systemic markers of inflammation (C-reactive protein, and erythrocyte sedimentation rate), and biomarker of intestinal inflammation [fecal calprotectin concentration (FCC)]. The SIBO rate was significantly higher in CD patients than in controls (32.6% vs. 12.4%, respectively, P=0.0008). Patients with and without SIBO were comparable with regard to demographics, systemic inflammatory biomarkers, and disease characteristics, except for the stricturing phenotype being more common in SIBO-positive CD patients (43.3% vs. 19.3%, P=0.015). Notably, FCC was significantly higher in SIBO-positive patients (median of 485.8 vs.132.7 μg/g; P=0.004). Patients presenting increased FCC and stricturing disease had an odds of 9.43 (95% confidence interval, 3.04-11.31; P<0.0001) and 3.83 (95% confidence interval, 1.54-6.75; P=0.025) respectively, for SIBO diagnosis. In CD patients, SIBO is a highly prevalent condition. Stricturing phenotype and increased FCC were strongly and independently associated with the presence of SIBO. SIBO diagnostic work-up followed by directed treatment is recommended in CD patients who present stricturing disease, especially in those with concurrent intestinal inflammation.

Small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome: Frequency and predictors

Small intestinal bacterial overgrowth (SIBO) has been implicated in pathogenesis of IBS. We aimed to study frequency and predictors of SIBO in patients with IBS. We included 59 consecutive patients of IBS & 37 healthy controls (HC). Evaluation for SIBO was done by glucose breath test (GBT) using 100 gm of glucose after an overnight fast. Breath hydrogen & methane concentration were noted at baseline & every 15 min after administration of glucose for a total of 3 h. Persistent rise in breath hydrogen or methane > 12 ppm above basal was considered diagnostic of SIBO. Of 59 patients, 27 were diarrhoea predominant (D-IBS), 11 were constipation predominant (C-IBS) and 21 were mixed type (M-IBS). Median age of patients (34 [18-47] years) were comparable to controls (35 [20-48] years) (P = 0.21). Patient group was similar to HC in gender distribution (male 41/59 [69.5%]vs 25/37 [67.6%], P = 0.36). SIBO was more frequent in patients with IBS than HC (14/59 [23.7%]vs 1/37 [2.7%], P = 0.008). Patients with D-IBS more often had SIBO as compared to non-D-IBS (10/27 [37%]vs 4/32 [12.5%], P = 0.02). C-IBS had lowest frequency of SIBO (1/11 [9%]) among all IBS subgroups. Patients with history of bloating more often had SIBO as compared to those without this symptom (11/23 [47.8%]vs 3/36 [8.3%], P = 0.002). Among IBS patients, females more often had SIBO as compared to males (8/18 [44.4%]vs 6/41 [14.6%], P = 0.01). SIBO was more frequent in patients with IBS as compared to healthy controls. D-IBS subtype, female gender & bloating were predictors of SIBO in patients with IBS.

Calcium Deficiency Is Associated with Small Intestinal Bacterial Overgrowth after Roux-en-Y Gastric Bypass Surgery

Purpose: We have shown that after Roux-en-Y gastric bypass surgery (GBS), patients frequently have elevated serum folate levels, a marker of small intestinal bacterial overgrowth (SIBO). Gastric pouch achlorhydria after GBS may lead to SIBO. Calcium deficiency with subsequent hyperparathyroidism and decreased bone mineral density has been reported after GBS. We hypothesize that by altering gut ecology, GBS induces calcium deficiency. Methods: This is a retrospective chart review of 452 patients who underwent Roux-en-Y gastric bypass surgery from 1999–2005. Of these patients, 154 had determination of serum folate, serum calcium, and 24 hour urinary calcium levels. Baseline patient demographics and characteristics included age, sex, and BMI. Glucose-hydrogen breath testing (HBT) had been performed in 43 patients (abnormal test was: hydrogen concentration >15 ppm over baseline fasting value or fasting hydrogen level >10 ppm). Results: In 129 female and 25 male patients, average age was 42 years (21 to 63 years) with BMI range of 40 to 80 kg/m2. Among 43 patients who underwent HBT, 42 had an abnormal breath test. Of these 42 patients, 38 also had elevated serum folate (90% sensitivity for elevated serum folate as a predictor of SIBO). Of 42 patients with abnormal HBT, 30 had low 24 hour urinary calcium (Chi-squared 2 × 2: P < .01). In the154 patients, 48 patients had normal serum folate levels of whom 38 had normal urinary calcium; in 106 patients with elevated serum folate, 80 had low 24 hour urinary calcium (Chi-squared 2 × 2: P < .001). Corrected serum calcium was within the normal range in all patients. Conclusion: Using HBT as the gold standard, almost all GBS patients who were tested had abnormal HBT, supporting the belief that SIBO is common after GBS. Elevated serum folate has a high sensitivity for detecting SIBO. Serum calcium determination is not accurate in predicting calcium metabolism in these patients. This study supports our hypothesis that by altering gut ecology, GBS induces calcium deficiency. Calcium malabsorption and secondary hyperparathyroidism may increase the risk for developing osteopenia, osteoporosis, and ultimately osteomalacia. Further studies of calcium metabolism after treatment of SIBO may support a treatment option for these patients.