Jejunal Aspirates Research Articles

Small Intestinal Bacterial Overgrowth Syndrome

Abstract Small intestinal bacterial overgrowth syndrome (SIBO) is a heterogeneous syndrome characterized by an increase in the number and/or presence of atypical bacteria in the small intestine. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms such as achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes and anatomical abnormalities such as small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections and motility disorders. Clinical signs of SIBO may be non-specific. Most often there is dyspepsia, diarrhoea, bloating and abdominal discomfort. SIBO can sometimes lead to malebsorption, severe malenutrition and/or other syndromes associated with nutritional deficiency. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen breath tests are most commonly used for diagnosis of SIBO. Therapy for SIBO must be complex. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO.

Small intestinal bacterial overgrowth among patients with celiac disease unresponsive to a gluten free diet.

Little is known about the relationship between small intestinal bacterial overgrowth (SIBO) and celiac disease (CeD) in patients who are unresponsive to a gluten-free diet (GFD). This study aimed to determine the SIBO prevalence in patients with CeD who are unresponsive to a GFD. We conducted a case-control study from July 2012 to September 2014. We included 32 patients with CeD who were unresponsive to a GFD and 52 healthy age- and sex-matched controls. Demographic, clinical, and laboratory data were obtained from patients' medical records. Antitissue transglutaminase antibody determined by enzyme-linked immunosorbent assay was recorded, and lactulose hydrogen breath test (LHBT) was used to detect SIBO in all participants. Microbiological analysis, including jejunal aspirates obtained using upper endoscopy, was performed for only 20 patients with CeD. A total of 10 (31%) of 32 patients with CeD and 4 (7.7%) of 52 controls tested positive for LHBT, with a statistically significant difference (p=0.007). Of 20 cultures, 3 (15%) were positive with no statistically significant correlation between the cultures and LHBT (p=0.05). In a subgroup analysis of children who were 18 years old or younger, 7/24 (29.2%) patients with CeD had a positive LHBT compared with 3/32 (9.4%) controls, but this difference was not statistically significant (p=0.08). The prevalence of SIBO was 31% in unresponsive patients with CeD according to LHBT and 15% in the quantitative culture of the jejunal aspirate, which is comparable with the published Western literature.

Delayed Gastric Emptying Is Not Associated with a Microbiological Diagnosis of Small Intestinal Bacterial Overgrowth.

Clinical symptoms of patients with small intestinal bacterial overgrowth (SIBO) may overlap with symptoms of gastroparesis. Prior studies suggest delayed small intestinal transit is associated with SIBO, but have not shown an association between delayed gastric emptying and SIBO. However, these studies have generally relied on the indirect method of breath testing to diagnose SIBO. The aim of this study was to examine the association between amicrobiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. In a single-center retrospective study of previous research participants who presented for small bowel enteroscopy for diagnostic evaluation of SIBO, we identified 73 participants who underwent gastric emptying study by scintigraphy. A microbiological diagnosis of SIBO was made in patients based on culture results of jejunal aspirates. Clinical symptoms were assessed using the total gastroparesis cardinal symptom index (GCSI) score. We compared delayed gastric emptying, 2- and 4-h gastric retention, and gastroparesis symptoms between patients with and without a microbiological diagnosis of SIBO. Among 29 participants with SIBO and 44 without SIBO, 33 (45%) had evidence of delayed gastric emptying. There was no significant association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. Percent retained at 2 and 4h, and total GCSI scores did not differ significantly between those with and without SIBO. Although delayed gastric emptying is common in patients with suspected SIBO, gastric emptying is not associated with a microbiological diagnosis of SIBO.

Correction to: Characterization of Proximal Small Intestinal Microbiota in Patients With Suspected Small Intestinal Bacterial Overgrowth: A Cross-Sectional Study.

Small intestinal bacterial overgrowth (SIBO) has historically been described in the context of maldigestion and malabsorption in patients with anatomic abnormalities (e.g., fistulae, strictures, bowel reconstruction, bowel obstruction), underlying dysmotility secondary to diabetes or scleroderma, and hypochlorhydria (1). This syndrome has also been implicated in the pathophysiology of numerous gastrointestinal and hepatobiliary diseases including common conditions such as irritable bowel syndrome (IBS) (2) and functional dyspepsia (3). Typical SIBO-associated symptoms include bloating, diarrhea, abdominal pain, and gas. SIBO symptoms may overlap with those of functional gastrointestinal disorders. However, the role of SIBO in the pathogenesis of functional gastrointestinal disorders remains controversial given that its definition relies on tests, including breath test and culture of small bowel aspirates, which have not been appropriately validated (4). Indirect techniques such as breath testing have important limitations related to heterogeneous testing methods and lack of standardization in interpretation. To address these limitations, guidelines for breath testing indications, performance, and interpretation were recently published in a North American consensus document (5). Yet, there remain important knowledge gaps in how these tests reflect the microbial landscape of the human small intestine. Small bowel aspirates and culture were previously considered the gold standard for the diagnosis of SIBO. SIBO has traditionally been defined by abnormally high amounts of bacteria in the small intestine and more precisely by >105 colony-forming units (CFU)/mL of colonic-type bacteria from jejunal aspirates (6). However, the validity of this approach has been questioned as the proposed cutoff of 105 seemed more predictive of postsurgical patients in a previous systematic review (7). Others have suggested that lower cutoff values of 103 CFU/mL be considered as diagnostic of SIBO (5), especially if coliforms are present (8). Standard culture-based techniques are limited in their ability to characterize fully the complex diversity of the small intestinal microbiome, particularly as a large proportion of bacterial species remain uncultured (9). In light of increasing evidence supporting the hypothesis that the intestinal microbiome serves a key role in host physiology and gastrointestinal disease, better characterization of the small intestinal microbiome will be a critical step in developing novel diagnostic and therapeutic strategies in a number of human diseases and disorders. In the recent years, the introduction of culture-independent techniques has dramatically expanded our ability to characterize the complexity of the intestinal microbiota. It also has increased our knowledge of the culture conditions needed to detect and identify previously difficult to culture organisms (10). Integration of rapid molecular approaches (11) for the assessment of SIBO in conditions such as IBS has yielded promising data including evidence for decreased microbial diversity from duodenal aspirates in patients with IBS compared with control subjects (12). However, these findings are preliminary. Overall, there are limited data reporting detailed characterizations of the human small intestinal microbiome. It may be hypothesized that alterations in the small intestinal microbiome are associated with culture-proven SIBO, which in turn could suggest that although imperfect, culture-proven SIBO is at least a useful surrogate marker of small intestinal dysbiosis. However, further investigation is needed to (i) explore the role of microbial diversity in SIBO using culture-independent approaches and (ii) describe the interactions between the host and small intestinal microbiome in the context of gastrointestinal disease. This study characterizes small intestinal microbial composition of small bowel aspirates and mucosal specimens in patients with and without a diagnosis of SIBO defined by qualitative and quantitative culture of proximal small bowel aspirates.

2603 Clostridioides difficile: Is Jejunum a New Reservoir?

INTRODUCTION: Clostridium difficile is the most common cause of healthcare associated infectious diarrhea. Normally inhabiting in the colon, this organism was found in jejunal aspirates, suggesting that the small bowel may act as reservoir. However, review of current literature showed C. difficile enteritis cases have occurred only in the presence of underlying surgical manipulation (resection/partial or total colectomy) or inflammatory bowel disease. Our patient is unique in not having any of the above-mentioned risk or predisposing factor, nor did he have any sign or symptom exhibiting any bowel disease. CASE DESCRIPTION/METHODS: A 35-year-old Caucasian male, presented to the hospital with complaint of severe acute abdominal pain, started as dull aching pain, about a week ago, associated with nausea and two episodes of loose stools, back pain and generalized body aches. He had a history of splenectomy due to ruptured splenic artery aneurysm and an episode of diverticulitis treated with intravenous antibiotics, 8 months ago. On the exam, he was found to have temperature of 38.1 deg. C with tachycardia and tachypnea. There was some tenderness to palpation over the epigastric region without any rebound tenderness. A white blood cell count showed leukocytosis of 34,000 cells/mm3. Intravenous Vancomycin and Piperacillin-Tazobactam were empirically started. A CT scan with intravenous contrast (without oral contrast) showed prominence of contiguous length of proximal and mid-jejunum in the left abdomen with concern for inflammation. Stool culture for Salmonella, Shigella, and Campylobacter was unremarkable, and Shiga toxin was negative. Two sets of blood culture obtained 15 minutes apart, didn’t grow any bacteria. Stool evaluation sent for C. difficile toxin Nucleic acid amplification Test (NAAT) was positive. He never had a C. difficile infection in the past. The intravenous antibiotics were discontinued and started on oral Vancomycin for 10 days. He significantly improved with the treatment; symptoms subsided and was discharged home. DISCUSSION: C. difficile, commonest cause for diarrhea in healthcare, can involve the small intestine, more so in surgically manipulated bowel or patients with IBD. As small bowel involvement is associated with a higher mortality than colonic involvement, it should be considered as a differential diagnosis for a patient presenting with enteritis, more so in patient with risk factors.

1179 Characterization of the Bacterial Makeup and Quantitative Distribution in Patients With Suspected Small Intestine Bacterial Overgrowth (SIBO): A Meta-Analysis

INTRODUCTION: Small Intestinal Bacterial Overgrowth (SIBO) is associated with abnormally high bacterial counts in the small intestine and clinical features such as diarrhea, constipation, abdominal pain, distension and bloating. A meta-analysis of studies of endoscopic samples from patients with suspected SIBO was performed to estimate the distribution of bacterial colony forming units (CFU) and identify the bacterial populations in these patients. METHODS: A literature search was performed to find studies of the jejunum or duodenum culture aspirates from patients with suspected SIBO using keywords: SIBO (or SBBO), culture aspirate and CFU. A total of 10 studies met the inclusion criteria. The CFU distribution was estimated using a log-spline smoothing technique in the statistical package R. Top bacterial population identified in aspirates of these patients was reviewed. RESULTS: The studies used in the meta-analysis including the number and type of subjects, the region where the culture aspirate sample was taken, and the type of CFU data presented was summarized in Table 1. A histogram of the estimated CFU distribution using the first five papers with actual CFU counts was shown in Figure 1. The spike at zero showed that approximately 26% of patients had sterile cultures. Sensitivity analyses using the first seven papers and all ten papers yielded similar estimated distributions to Figure 1, particularly in terms of the proportion of subjects with CFU counts between 104 and 106. The proportion of subjects in the tails of the distributions (sterile samples or CFU counts >1010) had larger variations between the three fitted distributions presumably due to differences in counting methodologies. The top bacterial species cultured and identified from jejunal aspirates was summarized in Table 2. CONCLUSION: Using a standard diagnostic threshold >105 CFU, only 24% of patients with suspected SIBO would test positive; while lowering the threshold to >104 CFU increases the positive call rate to 33%. As expected, bacterial culture identification was unable to clearly distinguish a single contributing organism. Limitations to this work are substantial and include variability in sampling regions, contamination, difficulty culturing and counting bacteria, lack of standardization in procedures and reproducibility. Given these limitations, there is consensus that novel tools are needed for evaluating patients with suspected SIBO.

The diagnosis of small intestinal bacterial overgrowth: Two steps forward, one step backwards?

Small intestinal bacterial overgrowth (SIBO) was originally described decades ago as a cause of malabsorption among individuals with abnormal intestinal anatomy and/or impaired gastric acid secretion and intestinal motor functions. More recently, the concept of SIBO has been expanded to explain symptoms among a much broader patient population-a move that brings the definition of SIBO into much sharper focus. For largely logistical reasons, breath tests and, especially, those based on the excretion of hydrogen consequent on the fermentation of unabsorbed carbohydrate substrates, have almost entirely replaced jejunal aspirates in the diagnosis of SIBO. Ever bedeviled by concerns regarding their reliability, hydrogen breath tests have now come under even more critical scrutiny with the study from Sundin and colleagues in this issue suggesting that their sole function is to detect carbohydrate malabsorption and that they are incapable of defining SIBO.

Does a glucose-based hydrogen and methane breath test detect bacterial overgrowth in the jejunum?

Direct diagnosis of small intestinal bacterial overgrowth (SIBO) requires the collection and culture of fluid from the jejunal lumen, with a finding of over 105 viable bacteria per mL. More often, SIBO is diagnosed indirectly, using a non-invasive test of the exhaled hydrogen and methane generated by microbial fermentation when ingested glucose reaches the jejunum. Our objective was to determine how well this breath test detects chronic overgrowth of jejunal bacteria that is unrelated to gastrointestinal surgery. Eighteen patients reporting symptoms consistent with SIBO received a glucose breath test. On a later day, the jejunal lumen was sampled via aspiration during enteroscopy. Jejunal aspirates were cultured on aerobic and anaerobic media. DNA was extracted from the same samples and analyzed by quantitative pan-bacterial PCR amplification of 16S ribosomal rRNA genes, which provided a culture-independent bacterial cell count. Combined bacterial colony counts ranged from 5.7x103 to 7.9x106 CFU/mL. DNA-based yields ranged from 1.5x105 to 3.1x107 bacterial genomes per mL. Microbial viability ranged from 0.3% to near 100%. We found no significant correlation of glucose breath test results with either the number of bacterial colonies or with the DNA-based bacterial cell counts. Instead, higher signals in the hydrogen-methane breath test were significantly correlated with a lower viability of jejunal bacteria, at a P-value of .014. The glucose-based hydrogen and methane breath test is not sensitive to the overgrowth of jejunal bacteria. However, a positive breath test may indicate altered jejunal function and microbial dysbiosis.

Gastrointestinal Involvement in Systemic Sclerosis: An Update.

Gastrointestinal Involvement in Systemic Sclerosis: An Update.

Low-grade small intestinal bacterial overgrowth is common in patients with non-alcoholic steatohepatitis on quantitative jejunal aspirate culture.

Though pathogenesis of non-alcoholic steatohepatitis (NASH) is unclear, association with small intestinal bacterial overgrowth [SIBO] and fecal dysbiosis is suggested. We evaluated SIBO in NASH using quantitative jejunal aspirate culture (conventional criteria: ≥ 105 colony forming unit (CFU)/mL and newer cutoff ≥ 103CFU/mL) and glucose hydrogen breath test. Thirty-eight patients with NASH (age 37.5years, range 20-54, 9, 24% female), diagnosed by ultrasonography, alanine aminotransferase >1.5 times normal and liver biopsy (in 27/38, 71%) and exclusion of other causes and 12 constipation-predominant irritable bowel syndrome as historical controls (age 39.5-y, 26-44; 3, 25% female) without fatty liver were studied. Jejunal aspirates, obtained in 35/38 patients, were sterile in 14/35 (40%) and bacteria isolated in 21 (60%) (all aerobic, in one anaerobe also; Gram positive 5, negative 13, both 3). In contrast, bacteria (two Gram negative) were isolated in 3/12 (25%) controls (odds ratio 4.5, 95% CI 1.0-19.5; p=0.04); colony counts were higher in NASH than controls (median 380CFU/mL, 0-200,000 vs. 0CFU/mL, 0-1000; p=0.02). Gram negative bacteria tended to be commoner in NASH than controls (16/35 vs. 2/12; p=0.07). Seven out of 35 (20%) patients with NASH (≥ 105CFU/mL in 5 and 2 other on glucose hydrogen breath test) and no control had SIBO (p=ns); low-grade SIBO (≥103CFU/mL) was commoner in NASH than controls (14/35, 40%, vs. 1/12, 8.3%; p=0.04). There was no correlation between bacterial colony count and bacterial type and anthropometric and biochemical parameters. Low-grade bacterial overgrowth, particularly with Gram negative bacteria, was commoner in NASH than controls.

Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS

There is a pressing need to develop a novel early-detection strategy for the precise evolution of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) patients. The current method based on a hydrogen breath test (HBT) for the detection of SIBO is highly controversial. HBT has many limitations and drawbacks. It often fails to indentify SIBO when IBS individuals have ‘non-hydrogen-producing’ colonic bacteria. Here, we show that hydrogen sulphide (H2S) in exhaled breath is distinctly altered for diarrhea-predominant IBS individuals with positive and negative SIBO by the activity of intestinal sulphate-reducing bacteria. Subsequently, by analyzing the excretion kinetics of breath H2S, we found a missing link between breath H2S and SIBO when HBT often fails to diagnose SIBO. Moreover, breath H2S can track the precise evolution of SIBO, even after the eradication of bacterial overgrowth. Our findings suggest that the changes in H2S in the bacterial environment may contribute to the pathogenesis of SIBO and the breath H2S as a potential biomarker for non-invasive, rapid and precise assessment of SIBO without the endoscopy-based microbial culture of jejunal aspirates, and thus may open new perspectives into the pathophysiology of SIBO in IBS subjects.

Gastrointestinal and Systemic Monitoring of Posaconazole in Humans After Fasted and Fed State Administration of a Solid Dispersion

The purpose of this study was to explore the intraluminal behavior and systemic exposure of posaconazole in humans after oral intake of a novel delayed-release tablet (Noxafil®), containing posaconazole dispersed in a matrix of hydroxypropyl methylcellulose acetate succinate. Five healthy volunteers were asked to ingest the tablet in the fasted and fed state condition, after positioning one aspiration catheter in the stomach and one in the jejunum. Subsequently, gastric and jejunal fluids were aspirated and analyzed for posaconazole. In parallel, blood samples were collected. In gastric aspirates, dissolved concentrations were negligible regardless of the test condition, confirming the delayed-release properties of the tablet. In fasted state jejunal aspirates, sustained supersaturation was observed during an average period of time of 93 ± 78.2 min, with a mean maximum degree of supersaturation of 7.28 ± 8.81. In the fed state condition, supersaturation was negligible in the jejunum with a pronounced presence of solid posaconazole, suggesting the importance of more distal intestinal regions for posaconazole absorption.

Mo1857 Role of PCR Amplification of Jejunal Aspirates in Relation to Culture and Breath Test in the Diagnosis of Small Intestinal Bacterial Overgrowth

Mo1857 Role of PCR Amplification of Jejunal Aspirates in Relation to Culture and Breath Test in the Diagnosis of Small Intestinal Bacterial Overgrowth

The Role of Helicobacter pylori in Patients with Hypothyroidism in Whom Could Not be Achieved Normal Thyrotropin Levels Despite Treatment with High Doses of Thyroxine

Helicobacter pylori infection is a most frequent cause of chronic gastritis. H. pylori may decrease absorption of oral thyroxine by decreasing gastric acid secretion in the stomach. In this study, we aimed to investigate the change in thyroid function tests of the cases after H. pylori eradication who were not responding to high doses of thyroxine treatment before H. pylori eradication. Hypothyroid cases who were not responding to high doses of thyroxine among the ones presented to Endocrinology and Gastroenterohepatology Clinics of Sisli Etfal Training and Research Hospital between 2009 and 2010 were included in the study. Thyroid function tests were performed two times in all cases before and after H. pylori eradication. Duodenal, antral and corporal biopsies, and jejunal aspirates and biopsies were taken during upper gastrointestinal system endoscopies performed in all patients. Cases without intestinal pathology were included in the study. Serum thyrotropin (TSH), free T3, and free T4 values before H. pylori eradication were 30.5 ± 28.8 IU/mL, 2.64 ± 0.56 pg/mL, and 0.92 ± 0.32 ng/mL, respectively, and after eradication were found to be 4.2 ± 10.6 IU/mL, 3.02 ± 0.61 pg/mL, and 1.3 ± 0.34 ng/mL, respectively (p values <.001, .002, and <.001, respectively). After H. pylori eradication treatment, TSH decreased in all of the cases, factitious thyrotoxicosis developed in % 21 of these cases. In hypothyroid cases, H. pylori gastritis may be responsible for an inadequate response to the treatment. H. pylori eradication in the cases receiving high doses of thyroxine has a risk for thyrotoxicosis.

Characterization of fasted-state human intestinal fluids collected from duodenum and jejunum

The solubility of drugs in the gastrointestinal tract is very challenging to simulate with artificial media due to the high complexity of human intestinal fluid (HIF). In particular, bile salt composition, pH and buffer capacity are very important characteristics of HIF, since they determine the solubility of drugs in-vivo. In this study, we have measured the concentrations of individual bile salts in human intestinal fluids (n=6) collected from two different locations (duodenum and jejunum) in the fasted state. Total bile salt concentrations ranged from 570 to 5,137 microM in the duodenum and from 829 to 5,470 microM in the jejunum. The following rank order of relative bile salt concentration in duodenum was observed: taurocholic acid > glycocholate >or= glycochenodeoxycholate > glycodeoxycholate > taurochenodeoxycholate > taurodeoxycholate. Cholic acid, tauroursodeoxycholate, chenodeoxycholic acid, and deoxycholic acid represented less than 1% of bile salts present in the samples. Ursodeoxycholate could not be detected in HIF. No statistically significant difference between bile salt composition of duodenal and jejunal aspirates was observed. The buffer capacity of HIF was compared with other media commonly used for solubility/dissolution determinations, indicating a relatively low buffer capacity of HIF (4-13 mmol L(-1)/pH). This low buffer capacity was reflected in the change in pH (between 4 and 9.5) that occurred in HIF after addition of model compounds covering a broad pK(a) range. Interindividual variability in pH, buffer capacity and bile salt contents of HIF will contribute to differences in the rate and extent of absorption of compounds for which dissolution/solubility is the rate limiting step. The variability observed warrants further research to explore the impact of intraluminal conditions on drug solubility.

Small intestinal bacterial overgrowth syndrome

Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO.

An Evidence-Based Systematic Review on the Management of Irritable Bowel Syndrome

An Evidence-Based Systematic Review on the Management of Irritable Bowel Syndrome

Critical Evaluation of Diagnosing Bacterial Overgrowth in the Proximal Small Intestine

Clinical small bowel bacterial overgrowth (SBBO) syndrome can be objectified by bacterial overgrowth tests. As direct culture of jejunal aspirates has disadvantages, noninvasive tests such as breath tests (BTs) are used. Major drawback of lactulose BT might be rapid lactulose transit to the colon. We evaluated diagnosing bacterial overgrowth using experimental and standard BT, and culture and molecular-based methods. Bacterial overgrowth was analyzed in 11 controls and 15 SBBO predisposed subjects. During experimental breath testing, an occlusive balloon limited lactulose to the small intestine. Jejunal fluid was analyzed using culture and molecular-based methods. Bacterial overgrowth was diagnosed on the basis of 20 ppm hydrogen or methane increase above baseline within 90 minutes or more than 10 CFU/mL excluding lactobacilli and streptococci and furthermore using all published definitions. Experimental and standard BT showed no changes in timing of hydrogen excretion between controls and SBBO subjects. Using standard BT, 3/11 controls and 8/15 SBBO subjects were bacterial overgrowth positive. Total counts showed no significant differences between controls and SBBO subjects using culture and molecular-based methods. Bacterial overgrowth was diagnosed in 0/9 controls and 4/12 SBBO subjects using culture-based methods. Other definitions used in literature revealed no significant differences between controls and SBBO subjects. In a small group of subjects, the experimental BT did not improve the ability of lactulose BT to diagnose bacterial overgrowth. Culturing showed less bacterial overgrowth in controls compared with BT. Remarkably, current diagnostic criteria do not seem to be accurate in discriminating between SBBO subjects and controls.

Intestinal bacterial metabolism of protein and bile acids: role in pathogenesis of hepatic disease after jejuno-ileal bypass surgery.

Jejunal bacterial colonization and intestinal metabolism of bile acids and protein by bacteria have been investigated in 12 patients with abnormal liver histology following jeujno-ileal bypass surgery for obesity. Aerobic and/or anaerobic colonic flora was present in jejunal aspirates from 8 of 12 bypass patients, but in none of the controls. Intestinal protein metabolism and bile acid deconjugation (measured by urinary indican excretion and 14C-glycocholic acid breath test) was significantly enhanced in bypass patients. Intestinal bacterial overgrowth, with abnormal intestinal metabolism by bacteria of ingested nutrients and bile acids, could contribute to hepatic disease after bypass surgery via the production of endogenous hepatotoxins.

Small intestinal motility disturbances and bacterial overgrowth in patients with liver cirrhosis and portal hypertension

Objectives Altered small bowel motility and a high prevalence of small intestinal bacterial overgrowth (SIBO) has been observed in patients with liver cirrhosis. Our aim was to explore the relationship between motility abnormalities, portal hypertension, and SIBO. Methods Twenty-four patients with liver cirrhosis were included. Twelve had portal hypertension (PH) and 12 had liver cirrhosis (LC) alone. Child-Pugh score was the same in the groups. Antroduodenojejunal pressure recordings were performed, and noninvasive variceal pressure measurements were undertaken. Thirty-two healthy volunteers served as a reference group. Bacterial cultures were obtained from jejunal aspirates. Results The PH group had a higher proportion of individual pressure waves that were retrograde in the proximal duodenum during phase II (52% vs 13% vs 8% of propagated contractions; p < 0.001) as well as postprandially (49% vs 18% vs 13%; p < 0.01) compared with LC and controls, respectively. Long clusters were more common in PH than in controls (9.1 ± 2.1 vs 4.9 ± 0.8; p < 0.05), and a higher motility index in phase III in the proximal and distal duodenum was seen in the PH as compared with the other groups. The mean variceal pressure was 21 ± 1 mm Hg. Motor abnormalities were not correlated to the level of variceal pressure. Thirty-three percent of the patients in the PH group but none in the LC group had SIBO. Conclusions Abnormal small bowel motility and SIBO is common in patients with liver cirrhosis with concomitant portal hypertension. Portal hypertension per se might be significantly related to small bowel abnormalities observed in patients with liver cirrhosis.