Prevalence Of Small Intestinal Bacterial Overgrowth Research Articles

Influence of Helicobacter pylori Infection and Eradication on Small Intestinal Bacterial Overgrowth and Abdominal Symptoms.

The relationship between Helicobacter pylori (H. pylori) infection and small intestinal bacterial overgrowth (SIBO) has attracted attention recently. To analyze the influence of H. pylori infection and eradication on SIBO, IMO, and abdominal symptoms. Patients with gastrointestinal symptoms were tested for 13C urea breath test and if positive, treated with bismuth-based quadruple therapy. Lactulose hydrogen methane breath test (HMBT) was performed and symptoms were assessed using gastrointestinal symptom rating scale (GSRS) before and 6weeks after eradication. Of the 102 subjects, 53 were H. pylori positive. The prevalence of SIBO and IMO were higher in patients with H. pylori infection than in those without infection (49.1% vs 24.5%, P = 0.019 for SIBO; 24.5% vs 8.2%, P = 0.027 for IMO). GSRS scores were similar between H. pylori-infected and uninfected patients (2 (IQR: 1;3) vs 2 (IQR: 1;2), P = 0.211). Patients with SIBO or IMO presented higher GSRS scores than patients with both SIBO and IMO negative (2 (IQR: 2;3), 2 (IQR: 2;3) vs 2 (IQR: 1;2), P = 0.011, 0.001, respectively). For the 50 patients who successfully eradicated H. pylori, the response rates for SIBO and IMO were 66.7% and 76.9%, respectively. GSRS scores also significantly decreased (2 (IQR: 1;3) to 0 (IQR: 0;1), P < 0.001) after eradication. Helicobacter pylori infection was associated with higher prevalence of SIBO and IMO, both of which led to more pronounced abdominal symptoms. H. pylori eradication also achieved therapeutic effects on SIBO and IMO, accompanied by relief of abdominal symptoms.

Prospective Monitoring of Small Intestinal Bacterial Overgrowth After Gastric Bypass: Clinical, Biological, and Gas Chromatographic Aspects.

Obesity is a predisposing factor for small intestinal bacterial overgrowth (SIBO). The aim of this study was to prospectively evaluate the prevalence of SIBO as well as its clinical, biological, and nutritional aspects before and up to 24months after a Roux-en-Y gastric bypass (RYGB) surgery. Fifty-one patients (mean BMI 46.9kg/m2, 66.7% women) requesting RYGB were included between 2016 and 2020. Each patient underwent a glucose breath test, a standardized interrogation on functional digestive signs, a dietary survey, a blood test, a fecalogram, and anthropometric data gathering. These investigations were carried out before surgery and at 1, 3, 6, 9, 12, 18, and 24months after RYGB. Before surgery, we found a prevalence of 17.6% of SIBO (95% CI = [8.9%; 31.4%]). After RYGB, at the end of 24months of follow-up, 89.5% of patients developed SIBO. Anal incontinence appeared to be very frequent after surgery, affecting 18.8% of our population 18months after surgery. We observed positive steatorrhea after surgery with an average of 11.1g of lipids/24h despite a significant limitation of dietary lipids (p = 0.0282). Our study corroborates data in the literature on the prevalence of SIBO in severe obesity patients. For the first time, we observed the sudden appearance of SIBO after RYGB, with a correlation between exhaled hydrogen on a breath test and lipid malabsorption on the fecalogram. As a result, these patients develop fatty diarrhea, with frequent fecal incontinence.

The Prevalence of Small Intestinal Bacterial Overgrowth After Roux-en-Y Gastric Bypass (RYGB): a Systematic Review and Meta-analysis.

We reviewed the literature on the prevalence of small intestinal bacterial overgrowth (SIBO) after Roux-en-Y gastric bypass (RYGB). Eight studies examining 893 patients were included. The mean age of the patients was 48.11 ± 4.89years. The mean BMI before surgery and at the time of SIBO diagnosis was 44.57 ± 2.89kg/m2 and 31.53 ± 2.29kg/m2, respectively. Moreover, the results showed a 29% and 53% prevalence of SIBO at < 3-year and > 3-year follow-up after RYGB, respectively. Symptoms included abdominal pain, diarrhea, bloating, nausea, vomiting, constipation, soft stool, frequent defecation, flatulence, rumpling, dumping syndrome, and irritable bowel syndrome. SIBO is prevalent after RYGB; digestive symptoms should prompt the consideration of SIBO as a potential etiology. Antibiotic therapy has proven to be therapeutic.

The prevalence and impact of small intestine bacterial overgrowth in biliary atresia patients.

Acute cholangitis is an ominous complication in biliary atresia (BA) patients. We investigated the prevalence of small intestine bacterial overgrowth (SIBO) in BA patients and its role in predicting acute cholangitis. There are 69 BA patients with native liver recruited into this study prospectively. They received hydrogen and methane-based breath testing (HMBT) to detect SIBO after recruitment and were followed prospectively in our institute. There are 16 (23.19%) subjects detected to have SIBO by HMBT. BA subjects with SIBO were noted to have higher serum alanine aminotransferase levels than others without SIBO (P = 0.03). The risk of acute cholangitis is significantly higher in BA patients with SIBO than in others without SIBO (62.50% vs. 15.09%, P < 0.001). The logistic regression analysis demonstrated that BA subjects with SIBO have a higher risk of acute cholangitis than others without SIBO (odds ratio = 9.38, P = 0.001). Cox's proportional hazard analysis further confirmed the phenomena in survival analysis (hazard ratio = 6.43, P < 0.001). The prevalence of SIBO in BA patients is 23.19% in this study. The presence of SIBO is associated with the occurrence of acute cholangitis in BA patients. What is the key message of your article? Acute cholangitis is common in BA, and is associated with SIBO after hepatoportoenterostomy in this study. What does it add to the existing literature? This study demonstrated that SIBO is common in BA after hepatoportoenterostomy, and is predictive of acute cholangitis and elevated serum ALT levels in BA. What is the impact? This prospective cohort study provides data regarding the significance of SIBO on the risk of acute cholangitis in BA patients.

Small Intestinal Bacterial Overgrowth Complicating Gastrointestinal Manifestations of Systemic Sclerosis: A Systematic Review and Meta-analysis

Systemic sclerosis (SSc) often is complicated by small intestinal bacterial overgrowth (SIBO). A systematic review and meta-analysis thus examined the prevalence of SIBO in SSc (SSc-subtypes), identify risk factors for SIBO in SSc and the effects of concomitant SIBO on gastrointestinal symptoms in SSc. We searched electronic databases until January-2022 for studies providing prevalence rates of SIBO in SSc. The prevalence rates, odds ratio (OR) and 95% confidence intervals (CI) of SIBO in SSc and controls were calculated. The final dataset comprised 28 studies with 1112 SSc-patients and 335 controls. SIBO prevalence in SSc-patients was 39.9% (95% CI, 33.1-47.1; P = 0.006), with considerable heterogeneity, (I2 = 76.00%, P < 0.001). As compared to controls, there was a 10-fold increased SIBO prevalence in SSc-patients (OR, 9.6; 95% CI, 5.6-16.5; P < 0.001). The prevalence of SIBO was not different in limited cutaneous SSc as compared to diffuse cutaneous SSc (OR, 1.01; 95% CI, 0.46-2.20; P = 0.978). Diarrhea (OR, 5.9; 95% CI, 2.9-16.0; P = 0.001) and the association between SIBO in SSc and proton pump inhibitor use (OR, 2.3; 95% CI, 0.8-6.4; P = 0.105) failed statistical significance. Rifaximin was significantly more effective as compared to rotating antibiotic in eradicating SIBO in SSc-patients (77.8% [95% CI, 64.4-87.9]) vs 44.8% [95% CI, 31.7-58.4]; P < 0.05). There is a 10-fold increased prevalence of SIBO in SSc, with similar SIBO prevalence rates in SSc-subtypes. Antimicrobial therapy of SIBO-positive SSc-patients with diarrhea should be considered. However, the results must be interpreted with caution due to substantial unexplained heterogeneity in the prevalence studies, and the low sensitivity and specificity of the diagnostic tests suggesting that the reliability of the evidence may be low.

Prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome (IBS): Correlating H2 or CH4 production with severity of IBS.

The prevalence and the role of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) remain unclear, as the literature provides heterogeneous information on the subject. The aim of this study was to determine the prevalence of SIBO in IBS and to assess the correlation between methane and hydrogen levels measured during breath tests and the severity of IBS. Two-hundred and forty-seven patients with IBS were prospectively included. A glucose breath test (GBT) measured H2 and CH4 production to diagnose SIBO. A test was positive when H2 values exceeded 12 ppm in the first 90 min and/or when a CH4 value exceeded 10 ppm at any time. IBS severity (IBS-SSS), quality of life (GIQLI), and anxiety and depression (HAD) were assessed to investigate the correlation with H2 and CH4 production. The prevalence of SIBO in IBS was 36.4% (9.7% with H2, 26.7% with CH4). CH4 levels were significantly higher in the predominantly constipated patients (P = 0.00), while H2 levels were significantly higher within the diarrheal phenotype (P = 0.01). IBS severity was not correlated with either H2 levels (r = 0.02; P = 0.84) or CH4 levels (r = 0.05; P = 0.64). H2 production was inversely correlated with the quality of life (r = -0.24; P = 0.03) and significantly correlated with the HAD scale (r = 0.22; P = 0.03). The pain and discomfort experienced during GBT was not correlated with methane levels (r = -0.09, P = 0.40), hydrogen levels (r = -0.01, P = 0.93), or sum of both (r = 0.06, P = 0.58), but significantly associated with IBS severity (r = 0.50, P <0.00). SIBO has a high prevalence in IBS but does not increase its severity. Individual susceptibility to pain may have a greater influence on the severity of IBS.

473 Exploring gastrointestinal bacterial colonization in rosacea as a biomarker for systemic abnormalities in innate immunity

OBJECTIVES/GOALS: To investigate the relationship between abnormal bacterial colonization of the gastrointestinal (GI) tract and systemic abnormalities in innate immunity as it contributes to the pathogenesis of rosacea. METHODS/STUDY POPULATION: This is a prospective observational study of patients with erythematotelangiectatic or papulopustular rosacea. The study participants will undergo urea breath testing for Helicobacter pylori (Hp) and hydrogen-methane breath testing for small intestinal bacterial overgrowth (SIBO). Colonic microbiome analysis will be performed using 16S rRNA sequencing of fecal samples. Further, key pro-inflammatory cytokines will be quantified from serum samples. Markers for rosacea subjects and subgroups will be compared by standard analysis of variance methods where appropriate, and Tukey studentized range tests will be done for specific comparisons. Chi-square tests will be used to assess group differences in categorical data. At least 42 subjects will be studied to provide 80% power atα-0.05. RESULTS/ANTICIPATED RESULTS: We hypothesize that the results of this study will support an observed relationship between abnormal GI bacterial colonization and systemic innate immunity abnormalities in rosacea as determined by three primary endpoints: a significantly greater prevalence of Hp and SIBO in rosacea participants, presence of pro-inflammatory cytokines linked to rosacea pathogenesis including interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and Granulocyte-macrophage colony-stimulating factor (GM-CSF), and observation of distinct, metabolically active colonic bacterial communities specific to rosacea participants. DISCUSSION/SIGNIFICANCE: By identifying rosacea as a cutaneous manifestation of a more systemic inflammatory disease, the results of this study will have implications for the development of important pharmacological interventions targeting key inflammatory pathways in rosacea pathogenesis.

Prevalence of Small Intestinal Bacterial Overgrowth Syndrome in Patients with Non-Alcoholic Fatty Liver Disease/Non-Alcoholic Steatohepatitis: A Cross-Sectional Study.

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial, wide-spectrum liver disorder. Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. SIBO, through energy salvage and induction of inflammation, may be a pathophysiological factor for NAFLD development and progression. Consecutive patients with histological, biochemical, or radiological diagnosis of any stage of NAFLD (non-alcoholic fatty liver [NAFL], non-alcoholic steatohepatitis [NASH], cirrhosis) underwent upper gastrointestinal endoscopy. Duodenal fluid (2cc) was aspirated from the 3rd-4th part of duodenum into sterile containers. SIBO was defined as ≥103 aerobic colony-forming units (CFU)/mL of duodenal aspirate and/or the presence of colonic-type bacteria. Patients without any liver disease undergoing gastroscopy due to gastroesophageal reflux disease (GERD) comprised the healthy control (HC) group. Concentrations (pg/mL) of tumor necrosis factor alpha (TNFα), interleukin (IL)-1β, and IL-6 were also measured in the duodenal fluid. The primary endpoint was to evaluate the prevalence of SIBO in NAFLD patients, while the comparison of SIBO prevalence among NAFLD patients and healthy controls was a secondary endpoint. We enrolled 125 patients (51 NAFL, 27 NASH, 17 cirrhosis, and 30 HC) aged 54 ± 11.9 years and with a weight of 88.3 ± 19.6 kg (NAFLD vs. HC 90.7 ± 19.1 vs. 80.8 ± 19.6 kg, p = 0.02). Overall, SIBO was diagnosed in 23/125 (18.4%) patients, with Gram-negative bacteria being the predominant species (19/23; 82.6%). SIBO prevalence was higher in the NAFLD cohort compared to HC (22/95; 23.2% vs. 1/30; 3.3%, p = 0.014). Patients with NASH had higher SIBO prevalence (6/27; 22.2%) compared to NAFL individuals (8/51; 15.7%), but this difference did not reach statistical significance (p = 0.11). Patients with NASH-associated cirrhosis had a higher SIBO prevalence compared to patients with NAFL (8/17; 47.1% vs. 8/51; 15.7%, p = 0.02), while SIBO prevalence between patients with NASH-associated cirrhosis and NASH was not statistically different (8/17; 47.1% vs. 6/27; 22.2%, p = 0.11). Mean concentration of TNF-α, IL-1β, and IL-6 did not differ among the different groups. The prevalence of SIBO is significantly higher in a cohort of patients with NAFLD compared to healthy controls. Moreover, SIBO is more prevalent in patients with NASH-associated cirrhosis compared to patients with NAFL.

Small Intestinal Bacterial Overgrowth in Patients with Gallbladder Polyps: A Cross-Sectional Study.

There is probably a high prevalence of small intestinal bacterial overgrowth (SIBO) in patients with gallbladder polyps (GBPs). To date, no study has evaluated the occurrence of SIBO in patients with GBPs. The aim of this study was to investigate the prevalence of SIBO in patients with GBPs and explore the possible association between these two conditions. The hydrogen-methane breath test was used to diagnose SIBO, and patients were divided into GBPs and control groups based on whether GBPs were found under ultrasound. Clinical and paraclinical factors were compared between the two groups. A total of 297 subjects were included in this study. The prevalence of SIBO was significantly higher in the GBPs group than in the control group (50.0% vs.30.8%, p<0.01). Multivariate logistic regression analysis showed that male (OR=2.26, 95% CI=1.12-4.57, p=0.023), SIBO (OR=3.21, 95% CI=1.69-6.11, p<0.001), fatty liver (OR=2.91, 95% CI= 1.50-5.64, p=0.002) and BMI (OR=1.13, 95% CI=1.01-1.26, p=0.035) were independently associated with GBPs. And by subgroup analysis, we found that the association between SIBO and GBPs was stronger in females than in males (p for interaction< 0.001). In addition, SIBO (OR=5.11, 95% CI=1.42-18.36, p=0.012) and fasting glucose (OR=3.04, 95% CI=1.27-7.28, p=0.013) were found to be associated with solitary polyps. SIBO was highly prevalent in patients with GBPs, and this association seemed to be stronger among females.

Assessment of small intestinal bacterial overgrowth and methane production in patients on chronic proton-pump inhibitor treatment: prevalence and role of rifaximin in its management in primary care.

Although proton pump inhibitor (PPI) drugs have considered able to induce small intestinal bacterial overgrowth (SIBO), no data are so far available from primary care (PC). We assessed the prevalence of SIBO and methane (CH<inf>4</inf>) production consequent to chronic PPI therapy using Lactulose Breath Test (LBT). Secondary aim was to explore the possible role of rifaximin in treating PPI-induced SIBO patients. One hundred twenty-five gastroesophageal reflux disease patients, constantly treated with PPI for at least 6 months and undergoing to LBT, were retrospectively assessed. An age-matched control population (control) of 100 patients, which had not used PPI in the last 6 months, was also enrolled. In the PPI group, SIBO positive patients and CH<inf>4</inf> producers were treated with rifaximin 1200 mg/daily for 14 days and re-checked with LBT one month after the end of treatment. The area under the curve (AUC) before and after treatment was also calculated for both SIBO positive patients and CH<inf>4</inf> producers. In the PPI group, SIBO prevalence was significantly higher vs. controls (38/125 [30.4%] vs. 27/100 [27%], P<0.05). 77/125 (61.6%) PPI patients were found to be CH<inf>4</inf> producers vs. 21/100 (21%) controls (P<0.05). Among SIBO patients in the PPI group, 34 (89.4%) were also CH<inf>4</inf> producers vs. 17/27 (63%) controls (P<0.05). After treatment, LBT resulted negative in 15/22 SIBO patients (68.1%) (P<0.05) and in 18/34 CH<inf>4</inf> producers (52.9%) (P<0.05). At the AUC analysis, an overall reduction of 54.2% for H<inf>2</inf> in SIBO patients and of 47.7% for CH<inf>4</inf> was assessed after rifaximin treatment (P<0.05). Our data showed that chronic use of PPI could be able to increase the prevalence of SIBO and to shift the intestinal microbial composition towards a CH4-producing flora. rifaximin could represent a useful therapeutical option for PPI-induced SIBO and for modulating CH4-producing flora.

Gut-Microbiota Dysbiosis in Stroke-Prone Spontaneously Hypertensive Rats with Diet-Induced Steatohepatitis

Metabolic-dysfunction-associated fatty-liver disease (MAFLD) is the principal worldwide cause of liver disease. Individuals with nonalcoholic steatohepatitis (NASH) have a higher prevalence of small-intestinal bacterial overgrowth (SIBO). We examined gut-microbiota isolated from 12-week-old stroke-prone spontaneously hypertensive-5 rats (SHRSP5) fed on a normal diet (ND) or a high-fat- and high-cholesterol-containing diet (HFCD) and clarified the differences between their gut-microbiota. We observed that the Firmicute/Bacteroidetes (F/B) ratio in both the small intestines and the feces of the SHRSP5 rats fed HFCD increased compared to that of the SHRSP5 rats fed ND. Notably, the quantities of the 16S rRNA genes in small intestines of the SHRSP5 rats fed HFCD were significantly lower than those of the SHRSP5 rats fed ND. As in SIBO syndrome, the SHRSP5 rats fed HFCD presented with diarrhea and body-weight loss with abnormal types of bacteria in the small intestine, although the number of bacteria in the small intestine did not increase. The microbiota of the feces in the SHRSP5 rats fed HFCD was different from those in the SHRP5 rats fed ND. In conclusion, there is an association between MAFLD and gut-microbiota alteration. Gut-microbiota alteration may be a therapeutic target for MAFLD.

Risk factors for small intestinal bacterial overgrowth in patients with acute ischaemic stroke.

Introduction. The intestinal flora has become a promising new target in acute ischaemic stroke (AIS), and small intestinal bacterial overgrowth (SIBO) is a common pathological condition of the intestinal flora. Recently, the lactose hydrogen-methane breath test has emerged as a non-invasive and economical method for the detection of SIBO in AIS patients. Exploring the prevalence of SIBO and its associated risk factors will provide a clinical basis for the association between intestinal flora and AIS.Hypothesis/Gap Statement. Given that the prevalence of SIBO and its risk factors in patients with AIS remain to be studied, there is a need to investigate them.Aim. This study aimed to investigate the prevalence and risk factors of SIBO in patients with AISMethodology. Eighty patients tested for SIBO using the lactulose hydrogen-methane breath test were evaluated. Patients were divided into SIBO-positive and SIBO-negative groups according to the presence or absence of SIBO, respectively. The baseline characteristics and clinical biochemical indicators of the patients were compared between the two groups. The independent risk factors and predictive value of SIBO in AIS patients were determined using multivariate logistic regression and receiver operating characteristic (ROC) curve analyses.Results. Of the 80 consecutive patients with AIS, 23 (28.8 %) tested positive for SIBO. Triglyceride (TG) and homocysteine (Hcy) levels were identified as independent risk factors for SIBO in patients with AIS using multivariate logistic regression analysis (P<0.005). ROC curve analysis showed that the area under the curve (AUC) of TG was 0.690 (95 % CI 0.577-0.789, P=0.002). The sensitivity, specificity and optimal cut-off values were 95.7 %, 35.1 % and 1.14 mmol l-1, respectively. The AUC of Hcy was 0.676 (95 % CI 0.562-0.776, P=0.01). The sensitivity, specificity and optimal cut-off values were 73.9 %, 59.7 % and 14.1 µmol-1, respectively. When TG and Hcy levels were combined, the AUC increased to 0.764 (95 % CI 0.656-0.852, P<0.001). The specificity and sensitivity were 61.4 and 82.6 %, respectively. This showed that the combined detection of TG and Hcy levels had a higher predictive valueConclusion. The prevalence of SIBO in patients with AIS was 28.8 %. TG and Hcy levels are independent risk factors for SIBO in patients with AIS. Both markers had good predictive value for the occurrence of SIBO. In the future, we should actively utilize these indicators to prevent intestinal flora imbalance and the occurrence of SIBO.

Lactase Deficiency Diagnosed by Endoscopic Biopsy-based Method is Associated With Positivity to Glucose Breath Test

Lactase deficiency, which has many similarities with small intestinal bacterial overgrowth (SIBO), causes various gastrointestinal symptoms. We estimate the prevalence of SIBO in patients with intestinal symptoms from dairy products and investigate the association between lactase deficiency (LD) and SIBO. This prospective study included patients with functional intestinal symptoms from dairy product indigestion. A questionnaire on gastrointestinal symptoms, a hydrogen (H2)-methane glucose breath test (GBT) for SIBO, and lactose intolerance quick test (LQT) for LD using upper gastrointestinal endoscopy were performed. A total of 88 patients, 29 (33.0%) with severe and 36 (40.9%) with mild LD were included. Sixteen patients (18.2%) were GBT positive. Patients with LQT negativity indicating severe LD showed a higher positivity to GBT or GBT (H2) than the historic controls (27.6% vs 6.7%, P = 0.032). There was no difference in the items on the symptom questionnaire according to the presence of LD or SIBO, except for higher symptom scores for urgency in GBT-positive patients. There were more LQT-negative patients in the GBT (H2)-positive group than in the other groups (27.6% vs 10.2%, P = 0.036). Moreover, only GBT (H2)-positivity was significantly associated with a higher risk of LQT negativity in multivariate analysis (OR, 4.19; P = 0.029). SIBO producing H2 is common in patients with severe LD suspected lactose intolerance. SIBO may be a new therapeutic target for managing intestinal symptoms in patients with lactose intolerance.

Prevalence of small intestinal bacterial overgrowth in patients with gastroparesis: a systematic review and meta-analysis.

We performed a systematic review and meta-analysis to identify the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with gastroparesis. Several studies have suggested an association between SIBO and gastroparesis, which is characterized by delayed gastric emptying in the absence of mechanical obstruction. A comprehensive search was performed using MEDLINE, EMBASE, Scopus and Cochrane Central Register of Controlled Trials (CENTRAL) through January, 2022 for randomized controlled trials and observational studies reporting the prevalence of SIBO in gastroparesis. Pooled prevalence was estimated using a random effects model. Heterogeneity was assessed by using the inconsistency index (I2). Among the 976 articles identified, 43 studies were selected for full text review. Six studies, with 385 patients, were deemed eligible for inclusion, with a perfect agreement between investigators (kappa=1.0). Overall, 379 patients were diagnosed with gastroparesis by gastric emptying scintigraphy and six were diagnosed with a wireless motility capsule. The pooled prevalence of SIBO was 41% (95% confidence interval 0.23-0.58). SIBO was diagnosed using jejunal aspirate cultures (N=15, 8.4%), lactulose breath test (N=80, 44.7%), glucose breath test (N=30, 16.8%), D-xylose breath test (N=52, 29.1%), and hydrogen breath test (N=2, 1.1%). Heterogeneity was significant and noted to be high at 91%. Only one study reported SIBO diagnosis in controls, therefore no pooled odds ratio was calculated. SIBO was present in almost half of the patients with gastroparesis. Future studies should examine and identify the association between SIBO and gastroparesis.

Hepatic Encephalopathy in Cirrhotic Patients and Risk of Small Intestinal Bacterial Overgrowth: A Systematic Review and Meta-Analysis.

Background Hepatic encephalopathy (HE) is a neurological and psychiatric syndrome. Recent evidence suggests that HE is not only a disease of the liver and brain but is also related to the gut. Small intestinal bacterial overgrowth (SIBO) is well known to be associated with cirrhosis, but the relationship between SIBO and HE is unclear. We conducted this comprehensive systematic review and meta-analysis to determine the association between SIBO and HE in cirrhotic patients. Methods We conducted a comprehensive literature search of all studies on the association of SIBO and HE in cirrhotic patients using the PubMed and Embase electronic databases. Studies were screened, and relevant data were extracted and analysed. We calculated the number of cases of SIBO in patients with HE and controls. We then compared the prevalence of SIBO between the two groups to calculate the odds ratios (ORs) and 95% confidence intervals (CIs). Funnel plots were constructed to identify potential publication bias. Results Six studies with 414 participants (219 HE patients and 195 controls) met the inclusion criteria. The prevalence of SIBO in cirrhotic patients with HE was significantly higher than that in those without HE. The combined OR was 4.43 (95% CI 1.73-11.32, P = 0.002). The heterogeneity was moderate (I2 = 66%), and the funnel plot suggested no significant publication bias. Subgroup analysis showed that the OR was 1.95 (95% CI 0.63–6.09) in studies using the lactulose breath test (LBT) and 7.60 (95% CI 3.50–16.50) in studies using the glucose breath test (GBT). The prevalence of SIBO in cirrhotic patients was also related to the severity of liver disease. Conclusions Our meta-analysis identified a strong association between SIBO and HE, and the risk of SIBO was 4.43 times higher among cirrhotic patients with HE than among those without HE. SIBO could be a predisposing factor for the development of HE in cirrhotic patients. Therefore, the importance of SIBO should be emphasized in patients with HE.

How to Recognize and Treat Small Intestinal Bacterial Overgrowth?

Small Intestinal Bacterial Overgrowth (SIBO) is a form of dysbiosis that involves increased bacterial colonization of the small intestine with some of the bacteria more characteristic of the colon microbiota. The prevalence of SIBO over recent decades has been estimated to range from 2.5 to 22% (depending on the source) and to increase with age and among individuals with comorbidities. Recently, an increase in the number of diagnosed SIBO cases has been observed, which is primarily due to the availability of noninvasive breath tests that facilitate the diagnostic process. However, SIBO is still both a diagnostic and a therapeutic problem. This review presents the pathophysiology, manifestations, diagnostics, and recommended management of SIBO.

Links between celiac disease and small intestinal bacterial overgrowth: A systematic review and meta-analysis.

Symptoms of small intestinal bacterial overgrowth (SIBO) and celiac disease (CeD) often overlap, and studies suggest a link between SIBO and CeD. We thus conducted a systematic review and meta-analysis to compare SIBO prevalence in CeD patients and controls and assessed effects of antimicrobial therapy on gastrointestinal symptoms in SIBO positive CeD patients. Electronic databases were searched until February 2022 for studies reporting SIBO prevalence in CeD. Prevalence rates, odds ratio (OR), and 95% confidence intervals (CI) of SIBO in CeD and controls were calculated. We included 14 studies, with 742 CeD patients and 178 controls. The pooled prevalence of SIBO in CeD was 18.3% (95% CI: 11.4-28.1), with substantial heterogeneity. Including case-control studies with healthy controls, SIBO prevalence in CeD patients was significantly increased (OR 5.1, 95% CI: 2.1-12.4, P=0.0001), with minimal heterogeneity. Utilizing breath tests, SIBO prevalence in CeD patients was 20.8% (95% CI: 11.9-33.7), almost two-fold higher compared with culture-based methods at 12.6% (95% CI: 5.1-28.0), with substantial heterogeneity in both analyses. SIBO prevalence in CeD patients nonresponsive to a gluten free diet (GFD) was not statistically higher as compared with those responsive to GFD (OR 1.5, 95% CI: 0.4-5.0, P=0.511). Antibiotic therapy of SIBO positive CeD patients resulted in improvement in gastrointestinal symptoms in 95.6% (95% CI: 78.0-99.9) and normalization of breath tests. This study suggests a link between SIBO and CeD. While SIBO could explain nonresponse to a GFD in CeD, SIBO prevalence is not statistically higher in CeD patients non-responsive to GFD. The overall quality of the evidence is low, mainly due to substantial "clinical heterogeneity" and the limited sensitivity/specificity of the available diagnostic tests.

High prevalence of small intestine bacteria overgrowth and asymptomatic carriage of enteric pathogens in stunted children in Antananarivo, Madagascar.

Environmental Enteric Dysfunction (EED) refers to an incompletely defined syndrome of inflammation, reduced absorptive capacity, and reduced barrier function in the small intestine. It is widespread among children and adults in low- and middle-income countries and is also associated with poor sanitation and certain gut infections possibly resulting in an abnormal gut microbiota, small intestinal bacterial overgrowth (SIBO) and stunting. We investigated bacterial pathogen exposure in stunted and non-stunted children in Antananarivo, Madagascar by collecting fecal samples from 464 children (96 severely stunted, 104 moderately stunted and 264 non-stunted) and the prevalence of SIBO in 109 duodenal aspirates from stunted children (61 from severely stunted and 48 from moderately stunted children). SIBO assessed by both aerobic and anaerobic plating techniques was very high: 85.3% when selecting a threshold of ≥105 CFU/ml of bacteria in the upper intestinal aspirates. Moreover, 58.7% of the children showed more than 106 bacteria/ml in these aspirates. The most prevalent cultivated genera recovered were Streptococcus, Neisseria, Staphylococcus, Rothia, Haemophilus, Pantoea and Branhamella. Feces screening by qPCR showed a high prevalence of bacterial enteropathogens, especially those categorized as being enteroinvasive or causing mucosal disruption, such as Shigella spp., enterotoxigenic Escherichia coli, enteropathogenic E. coli and enteroaggregative E. coli. These pathogens were detected at a similar rate in stunted children and controls, all showing no sign of severe diarrhea the day of inclusion but both living in a highly contaminated environment (slum-dwelling). Interestingly Shigella spp. was the most prevalent enteropathogen found in this study (83.3%) without overrepresentation in stunted children.

The Apparent Asymmetrical Relationship Between Small Bowel Bacterial Overgrowth, Endotoxemia, and Liver Steatosis and Fibrosis in Cirrhotic and Non-Cirrhotic Patients: A Single-Center Pilot Study

IntroductionGut microbiota are a complex ecosystem harboring our intestine. They maintain human body equilibrium, while their derangement, namely, “dysbiosis“, has been associated with several gastrointestinal diseases, such as liver steatosis (NAFLD) and liver cirrhosis. Small intestinal bacterial overgrowth (SIBO) is an example of dysbiosis of the upper gastrointestinal (GI) tract.AimThe aim of this study is to evaluate the relationship between SIBO and levels of endotoxemia and grade of liver steatosis (LS) and liver fibrosis (LF) in hepatologic patients.Materials and MethodsConsecutive outpatients referred to our hepatology clinic were tested for SIBO by the lactulose breath test (LBT) and peripheral blood levels of endotoxemia; LS grading and LF were assessed by abdominal ultrasound and transient elastography, respectively.ResultsFifty-two consecutive patients (17 with alcohol abuse (4.5 ± 0.8 alcohol units per day), 4 with HCV and 2 with HBV infection, 24 of metabolic origin, 2 of autoimmune origin, and 3 with cholangiopathies; mean age 54.7 ± 8.3 years, 31 F, BMI 24.1 ± 1.1 Kg/m2) and 14 healthy volunteers (HV) (mean age 50.1 ± 4.3 years, 9 F, BMI 23.3 ± 1.1 Kg/m2) were enrolled. SIBO prevalence was significantly higher in cirrhotic (LC) vs. non-cirrhotic (LNC) patients and vs. HV (all, p < 0.05), with a significant positive trend according to Child-Pugh status (all, p < 0.05). SIBO prevalence was not correlated with LS stages (all, p = NS). Consensually, endotoxin levels were significantly higher in LC vs. LNC and vs. HV (all, p < 0.05) and significantly correlated with LF in patients with LC, according to Child-Pugh status (all, p < 0.05).ConclusionThis study shows that SIBO prevalence and relative endotoxin blood levels seem to be significantly associated with the grade of LF vs. LS in LC. SIBO is also present under pre-cirrhotic conditions, but its prevalence seems to correlate with liver disease irreversible derangement.

Role of Glucose Breath Test for Small Intestinal Bacterial Overgrowth in Children and Adolescents With Functional Abdominal Pain Disorders in Korea.

Background/AimsSmall intestinal bacterial overgrowth (SIBO) is expected in children and adolescents with functional abdominal pain disorders (FAPDs). This study is conducted to estimate the prevalence of SIBO and to investigate the role of SIBO in children and adolescents with FAPDs.MethodsThis prospective study enrolled children with FAPDs fulfilling the Rome IV criteria. A hydrogen-methane glucose breath test was used to diagnose SIBO. A survey of bowel symptoms using questionnaires, birth history, types of feeding, and the presence of allergy was conducted.ResultsSixty-eight children and adolescents (range, 6-17 years; median, 12.5 years) were enrolled. SIBO was detected in 14 patients (20.6%). Age (≥ 12 years) (P < 0.003) and loose stool (P = 0.048) were significantly more common in children with SIBO than in children without SIBO. However, the history of allergies (P = 0.031) was less common in children with SIBO than those without SIBO. No significant differences were observed in other demographic findings. In multivariate analysis, age (≥ 12 years) was the independent factor predicting SIBO in children with FAPDs.ConclusionsSIBO is not uncommon in children and adolescents with FAPDs. Among children aged above 12 years and diagnosed with FAPDs, SIBO is a suspected clinical target for treatment to relieve intestinal symptoms. A further study to investigate the association between intestinal bacteria and history of allergy is needed.