Small Bowel Bacterial Overgrowth: Presentation, Diagnosis, and Treatment

Chronic pancreatitis for the clinician: complications and special forms of the disease. Interdisciplinary position paper of the Catalan Society of Digestology (SCD) and the Catalan Pancreatic Society (SCPanc)

Chronic pancreatitis tends to develop a number of complications that may constitute the form of presentation of the disease. Some societies have issued guidelines for diagnosis and treatment of chronic pancreatitis complications, but the level of evidence for any topic is usually low and recommendations tend to be weak. We aimed to provide defined position statements for the clinician based on updated review of published literature and on multidisciplinary expert agreement. The goal was to propose defined terminology and rational diagnostic/therapeutic circuits based on current knowledge. To this end 14 sections related to complications and special forms of chronic pancreatitis (early chronic, groove and autoimmune pancreatitis) were reviewed by 21 specialists from 6 different fields to generate 32 statements. Featured statements assert common bile duct stenosis does not require invasive treatment (endoscopic or surgical) unless cholestasis, cholangitis, lithiasis or other symptoms develop. Pancreatic duct strictures and calculi should be approached (after ruling out malignancy) if causing pain, pancreatitis, pseudocysts or other complications. Treatment of symptomatic pseudocysts must be individualized, considering associated main duct stenosis, vascular and pericystic complications. Higher risk conditions for pancreatic cancer are advance age, smoking, genetic background, recent diagnosis of chronic pancreatitis or diabetes, and appearance of new symptoms. Groove pancreatitis can initially be treated with conservative measures. Both prednisolone or rituximab can induce remission and maintenance of autoimmune pancreatitis. Internal fistula, vascular complications, bacterial overgrowth, osteoporosis and renal lithiasis require specific therapeutic approaches.

Dioxin-elicited decrease in cobalamin redirects propionyl-CoA metabolism to the β-oxidation-like pathway resulting in acrylyl-CoA conjugate buildup

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant that induces diverse biological and toxic effects, including reprogramming intermediate metabolism, mediated by the aryl hydrocarbon receptor. However, the specific reprogramming effects of TCDD are unclear. Here, we performed targeted LC-MS analysis of hepatic extracts from mice gavaged with TCDD. We detected an increase in S-(2-carboxyethyl)-L-cysteine, a conjugate from the spontaneous reaction between the cysteine sulfhydryl group and highly reactive acrylyl-CoA, an intermediate in the cobalamin (Cbl)-independent β-oxidation-like metabolism of propionyl-CoA. TCDD repressed genes in both the canonical Cbl-dependent carboxylase and the alternate Cbl-independent β-oxidation-like pathways as well as inhibited methylmalonyl-CoA mutase (MUT) at lower doses. Moreover, TCDD decreased serum Cbl levels and hepatic cobalt levels while eliciting negligible effects on gene expression associated with Cbl absorption, transport, trafficking, or derivatization to 5'-deoxy-adenosylcobalamin (AdoCbl), the required MUT cofactor. Additionally, TCDD induced the gene encoding aconitate decarboxylase 1 (Acod1), the enzyme responsible for decarboxylation of cis-aconitate to itaconate, and dose-dependently increased itaconate levels in hepatic extracts. Our results indicate MUT inhibition is consistent with itaconate activation to itaconyl-CoA, a MUT suicide inactivator that forms an adduct with adenosylcobalamin. This adduct in turn inhibits MUT activity and reduces Cbl levels. Collectively, these results suggest the decrease in MUT activity is due to Cbl depletion following TCDD treatment, which redirects propionyl-CoA metabolism to the alternate Cbl-independent β-oxidation-like pathway. The resulting hepatic accumulation of acrylyl-CoA likely contributes to TCDD-elicited hepatotoxicity and the multihit progression of steatosis to steatohepatitis with fibrosis.

Small Intestinal Bacterial Overgrowth in Children: Clinical Features and Treatment Response

To characterize the population of children diagnosed with small intestinal bacterial overgrowth (SIBO) based on breath test (BT), correlate symptomatology, and describe SIBO treatments and treatment efficacy.

Methods

A retrospective cohort study of pediatric patients seen at Stanford Children's Health Gastroenterology Clinics from 2012 to 2018 who had a positive BT, defined by a rise in hydrogen by ≥20 ppm, a baseline hydrogen level ≥20 ppm, or a methane value ≥10 ppm. The main outcome was symptom resolution, defined as complete or partial improvement after a course of treatment. Absolute standardized differences and Chi-square tests were used to assess associations.

Results

From 98 children, 54 met inclusion and did not meet exclusion criteria (53.7% female). Lactulose substrate was used for 41 (75.9%) patients, whereas glucose was used for 13 (24.1%). Complete or partial resolution of symptoms was achieved in 13 of 16 (81.2%) patients who received probiotics with or without antibiotics versus 21 of 31 (67.7%) patients treated with antibiotics alone (P = 0.524). Metronidazole versus rifaximin versus other antibiotics showed no significant difference in symptom resolution (12 (63.2%), 13 (76.5%), 7 (77.8%), respectively, P = 0.601).

Conclusion

Seventy-two percent of patients experienced at least partial symptom relief after treatment. We did not find a strong correlation between specific symptoms and analyte elevation. There was no difference in effectiveness between metronidazole and rifaximin to treat SIBO symptoms. Further research needs to be done to determine effective treatments for SIBO in pediatrics.

D-lactic acidosis presenting as metabolic encephalopathy in a patient with short bowel syndrome

We present a case of D-lactic acidosis presenting as a metabolic encephalopathy secondary to small intestinal bacterial overgrowth. This patient had a known history of short bowel syndrome. Of note, this case required the alteration of treatment to promote a sustained clinical and biochemical improvement. We discuss the pathophysiological mechanisms thought to be involved. We also review the current therapies as well as potential future strategies. This case highlights the importance of the prompt clinical recognition of signs and symptoms as well as the rapid initiation of management strategies to ameliorate this condition.

Medical Management of Chronic Pancreatitis in Children: A Position Paper by the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Pancreas Committee

ABSTRACT

This position paper summarizes the current understanding of the medical management of chronic pancreatitis (CP) in children in light of the existing medical literature, incorporating recent advances in understanding of nutrition, pain, lifestyle considerations, and sequelae of CP. This article complements and is intended to integrate with parallel position papers on endoscopic and surgical aspects of CP in children. Concepts and controversies related to pancreatic enzyme replacement therapy (PERT), the use of antioxidants and other CP medical therapies are also reviewed. Highlights include inclusion of tools for medical decision-making for PERT, CP-related diabetes, and multimodal pain management (including an analgesia ladder). Gaps in our understanding of CP in children and avenues for further investigations are also reviewed.

Small intestinal bacterial overgrowth as a cause of protracted wound healing and vitamin D deficiency in a spinal cord injured patient with a sacral pressure sore: a case report

BACKGROUND

Pressure sores are sometimes refractory to treatment, often due to malnutrition. Small intestinal bacterial overgrowth (SIBO) obstructs absorption in the digestive tract and causes malnutrition. However, little is known about the association between pressure sore wound healing and SIBO. Here, we report a case of a patient with a refractory sacral pressure sore and SIBO.

CASE PRESENTATION

A 66-year-old woman who was spinal cord injured 14 years before visiting our hospital presented with the chief complaint of a sacral pressure sore, 10.0 × 6.5 cm in size, which was refractory to treatment. Physical examination showed abdominal distension and emaciation, with a body mass index of 15. Further examination revealed elevated serum alkaline phosphatase (1260 U/L), bilateral tibial fracture, multiple rib fracture, and osteoporosis. We diagnosed the patient with osteomalacia with vitamin D deficiency. Despite oral supplementation, serum levels of calcium, phosphorous, and vitamin D remained low. Also, despite concentrative wound therapy for the sacral pressure sore by plastic surgeons, no wound healing was achieved. Due to a suspicion of disturbances in nutrient absorption, we performed bacterial examination of collected gastric and duodenal fluid, which showed high numbers of bacteria in gastric content (10⁴ E. coli, 10⁵ Streptococcus species, and 10⁵ Neisseria species) and duodenal content (10⁶ E. coli, 10⁴ Candida glabrata). Therefore, we diagnosed the patient with SIBO and started selective decontamination of the digestive tract using polymyxin B sulfate and amphotericin B. After starting treatment for SIBO, the sacral pressure sore began to heal and was nearly healed after 285 days. The patient's serum levels of calcium, phosphorous, vitamin D, and other fat-soluble vitamins also gradually increased after starting treatment for SIBO.

CONCLUSION

We report a case of a patient with a refractory sacral pressure sore that healed after starting treatment for SIBO. We conclude that SIBO may be an overlooked cause of malnutrition and poor wound healing in patients with chronic pressure sores.

The Influence of Small Intestinal Bacterial Overgrowth in Digestive and Extra-Intestinal Disorders

Small intestinal bacterial overgrowth (SIBO) is a condition hallmarked by an increase in the concentration of colonic-type bacteria in the small bowel. Watery diarrhea, bloating, abdominal pain and distension are the most common clinical manifestations. Additionally, malnutrition and vitamin (B12, D, A, and E) as well as minerals (iron and calcium) deficiency may be present. SIBO may mask or worsen the history of some diseases (celiac disease, irritable bowel disease), may be more common in some extra-intestinal disorders (scleroderma, obesity), or could even represent a pathogenetic link with some diseases, in which a perturbation of intestinal microbiota may be involved. On these bases, we performed a review to explore the multiple links between SIBO and digestive and extra-intestinal diseases.

Lactose intolerance in children and adults

Lactose is a disaccharide found in milk and dairy products. Children and adults with lactose intolerance are unable to tolerate significant amounts of lactose because of an inadequate amount of the enzyme lactase. The condition occurs in three main types: primary, secondary, and primary adult-type hypolactasia. The use of milk in the diet of these individuals may lead to appearance of the irritable bowel syndrome. In persons with lactose intolerance symptoms include diarrhoea, dominated by abdominal colic, loud peristaltic sounds, increased flatulence and meteorism. A diagnosis of lactose intolerance can usually be made with a careful history, elimination of lactose from the diet, lactose tolerance test, hydrogen breath test and genetic testing. In the absence of appropriate tests in patients with suspected primary adult-type hypolactasia, diagnosis can be made as in patients with food allergy. Treatment is based on the restriction of lactose intake with the use of fermented milk products. However, especially for children, if milk and dairy products are eliminated from the diet, it is important to ensure D vitamin and calcium supplementation.

Small Intestinal Bacterial Overgrowth Is Common in Chronic Pancreatitis and Associates With Diabetes, Chronic Pancreatitis Severity, Low Zinc Levels, and Opiate Use

OBJECTIVES

Small intestinal bacterial overgrowth (SIBO) is often present in patients with chronic pancreatitis (CP) with persistent steatorrhea, despite pancreatic enzyme replacement therapy. Overall prevalence of SIBO, diagnosed by glucose breath test (GBT), varies between 0% and 40% but 0%-21% in those without upper gastrointestinal (GI) surgery. We investigated the prevalence and nonsurgical independent predictors of SIBO in CP without upper GI surgery.

METHODS

Two hundred seventy-three patients ≥18 years old had a presumptive diagnosis of CP and a GBT between 1989 and 2017. We defined CP by Mayo score (0-16) ≥4 and a positive GBT for SIBO by Rome consensus criteria and retrospectively collected data for 5 a priori variables (age, opiates, alcohol use, diabetes mellitus (DM), gastroparesis) and 41 investigational variables (demographics, GI symptoms, comorbidities, CP etiologies and cofactors, CP symptom duration, Mayo score and nondiabetes components, and biochemical variables).

RESULTS

Ninety-eight of 273 patients had definite CP and 40.8% had SIBO. Five of 46 variables predicted SIBO: opiates, P = 0.005; DM, P = 0.04; total Mayo score, P < 0.05; zinc, P = 0.005; and albumin, P < 0.05). Multivariable analysis of 3 noncorrelated variables identified zinc level (odds ratio = 0.0001; P = 0.03) as the sole independent predictor of SIBO (model C-statistic = 0.89; P < 0.001).

DISCUSSION

SIBO, diagnosed by GBT, occurs in 40.8% of patients with CP without upper GI surgery. In patients with CP, markers of more severe CP (low zinc level, DM and increased Mayo score) and opiate use should raise clinical suspicion for SIBO, particularly in patients with persistent steatorrhea or weight loss despite pancreatic enzyme replacement therapy.

Uncommon Diverticular Disease

This article describes the epidemiology, pathogenesis, diagnosis, and treatment of three rare variants of diverticular disease: cecal and right-sided colonic diverticula, giant colonic diverticula, and small bowel diverticula.

Increase in breath hydrogen concentration was correlated with the main pancreatic duct stenosis

BACKGROUND

Hydrogen is produced from unabsorbed carbohydrates in the intestine through degradation and metabolism by hydrogenase of intestinal bacteria. The hydrogen is then partially diffused into blood flow and released and detected in exhaled breath. Pancreatic juice production is decreased in patients with reduced pancreatic exocrine function, including those with pancreatic cancer, thus decreasing digestion and absorption of nutrients including carbohydrates, which may increase undigested carbohydrates in the intestine and increase breath hydrogen concentration (BHC). The aim of this study was to investigate the association between BHC and pancreatic diseases.

METHODS

A retrospective study was designed and 68 patients underwent morning fasting breath hydrogen test. Since there is no clear standard, normal BHC, the median of the measured values from the subjects (9 ppm) was adopted as the standard. The subjects were classified into those with a value exceeding the median (BHC high group: 32 patients) and a value equal to or below the median (BHC low group: 36 patients). Patients characteristics, blood test results and imaging findings characteristic of pancreatic diseases were compared between the groups.

RESULTS

The age was significantly higher (P = 0.010) and the incidences of pancreatic ductal adenocarcinoma and autoimmune pancreatitis were significantly higher (P = 0.018 and P = 0.004, respectively) in the BHC high group. With respect to the blood test items, the Alb level was significantly lower in the BHC high group (P = 0.005). With respect to the characteristic imaging findings of pancreatic diseases, the proportions of patients with pancreatic enlargement, the main pancreatic duct (MPD) stenosis, and the MPD dilatation were significantly higher in the BHC high group (P = 0.022, P < 0.001, and P = 0.002, respectively). On univariate analysis, only the MPD stenosis was extracted as an independent factor (P = 0.014).

CONCLUSION

It was suggested that the fasting BHC is associated with pancreatic diseases causing stenosis of the MPD, including pancreatic cancer (UMIN000020777).

Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy

The pathogenesis of irritable bowel syndrome (IBS), once thought to be largely psychogenic in origin, is now understood to be multifactorial. One of the reasons for this paradigm shift is the realization that gut dysbiosis, including small intestinal bacterial overgrowth (SIBO), causes IBS symptoms. Between 4% and 78% of patients with IBS and 1% and 40% of controls have SIBO; such wide variations in prevalence might result from population differences, IBS diagnostic criteria, and, most importantly, methods to diagnose SIBO. Although quantitative jejunal aspirate culture is considered the gold standard for the diagnosis of SIBO, noninvasive hydrogen breath tests have been popular. Although the glucose hydrogen breath test is highly specific, its sensitivity is low; in contrast, the early-peak criteria in the lactulose hydrogen breath test are highly nonspecific. Female gender, older age, diarrhea-predominant IBS, bloating and flatulence, proton pump inhibitor and narcotic intake, and low hemoglobin are associated with SIBO among IBS patients. Several therapeutic trials targeting gut microbes using antibiotics and probiotics have further demonstrated that not all symptoms in patients with IBS originate in the brain but rather in the gut, providing support for the micro-organic basis of IBS. A recent proof-of-concept study showing the high frequency of symptom improvement in patients with IBS with SIBO further supports this hypothesis.

Irritable Bowel Syndrome May Be Associated with Elevated Alanine Aminotransferase and Metabolic Syndrome

PURPOSE

Recent studies have revealed close relationships between hepatic injury, metabolic pathways, and gut microbiota. The microorganisms in the intestine also cause irritable bowel syndrome (IBS). The aim of this study was to examine whether IBS was associated with elevated hepatic enzyme [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], gamma-glutamyl transferase (γ-GT) levels, and metabolic syndrome (MS).

MATERIALS AND METHODS

This was a retrospective, cross-sectional, case-control study. The case and control groups comprised subjects who visited our health promotion center for general check-ups from June 2010 to December 2010. Of the 1127 initially screened subjects, 83 had IBS according to the Rome III criteria. The control group consisted of 260 age- and sex-matched subjects without IBS who visited our health promotion center during the same period.

RESULTS

Compared to control subjects, patients with IBS showed significantly higher values of anthropometric parameters (body mass index, waist circumference), liver enzymes, γ-GT, and lipid levels. The prevalences of elevated ALT (16.9% vs. 7.7%; p=0.015) and γ-GT (24.1% vs. 11.5%; p=0.037) levels were significantly higher in patients with IBS than in control subjects. A statistically significant difference was observed in the prevalence of MS between controls and IBS patients (12.7% vs. 32.5%; p<0.001). The relationships between elevated ALT levels, MS, and IBS remained statistically significant after controlling for potential confounding factors.

CONCLUSION

On the basis of our study results, IBS may be an important condition in certain patients with elevated ALT levels and MS.

Lactose Intolerance in Adults: Biological Mechanism and Dietary Management

Lactose intolerance related to primary or secondary lactase deficiency is characterized by abdominal pain and distension, borborygmi, flatus, and diarrhea induced by lactose in dairy products. The biological mechanism and lactose malabsorption is established and several investigations are available, including genetic, endoscopic and physiological tests. Lactose intolerance depends not only on the expression of lactase but also on the dose of lactose, intestinal flora, gastrointestinal motility, small intestinal bacterial overgrowth and sensitivity of the gastrointestinal tract to the generation of gas and other fermentation products of lactose digestion. Treatment of lactose intolerance can include lactose-reduced diet and enzyme replacement. This is effective if symptoms are only related to dairy products; however, lactose intolerance can be part of a wider intolerance to variably absorbed, fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). This is present in at least half of patients with irritable bowel syndrome (IBS) and this group requires not only restriction of lactose intake but also a low FODMAP diet to improve gastrointestinal complaints. The long-term effects of a dairy-free, low FODMAPs diet on nutritional health and the fecal microbiome are not well defined. This review summarizes recent advances in our understanding of the genetic basis, biological mechanism, diagnosis and dietary management of lactose intolerance.

Clinical significance of the glucose breath test in patients with inflammatory bowel disease

BACKGROUND AND AIM

Small intestinal bacterial overgrowth which has recently been diagnosed with the glucose breath test is characterized by excessive colonic bacteria in the small bowel, and results in gastrointestinal symptoms that mimic symptoms of inflammatory bowel disease. This study aimed to estimate the positivity of the glucose breath test and investigate its clinical role in inflammatory bowel disease.

METHODS

Patients aged > 18 years with inflammatory bowel disease were enrolled. All patients completed symptom questionnaires. Fecal calprotectin level was measured to evaluate the disease activity. Thirty historical healthy controls were used to determine normal glucose breath test values.

RESULTS

A total of 107 patients, 64 with ulcerative colitis and 43 with Crohn's disease, were included. Twenty-two patients (20.6%) were positive for the glucose breath test (30.2%, Crohn's disease; 14.1%, ulcerative colitis). Positive rate of the glucose breath test was significantly higher in patients with Crohn's disease than in healthy controls (30.2% vs 6.7%, P=0.014). Bloating, flatus, and satiety were higher in glucose breath test-positive patients than glucose breath test-negative patients (P=0.021, 0.014, and 0.049, respectively). The positivity was not correlated with the fecal calprotectin level.

CONCLUSIONS

The positive rate of the glucose breath test was higher in patients with inflammatory bowel disease, especially Crohn's disease than in healthy controls; gastrointestinal symptoms of patients with inflammatory bowel disease were correlated with this positivity. Glucose breath test can be used to manage intestinal symptoms of patients with inflammatory bowel disease.

Gut microbiota in alcoholic liver disease: Pathogenetic role and therapeutic perspectives

Alcoholic liver disease (ALD) is the commonest cause of cirrhosis in many Western countries and it has a high rate of morbidity and mortality. The pathogenesis is characterized by complex interactions between metabolic intermediates of alcohol. Bacterial intestinal flora is itself responsible for production of endogenous ethanol through the fermentation of carbohydrates. The intestinal metabolism of alcohol produces a high concentration of toxic acetaldehyde that modifies gut permeability and microbiota equilibrium. Furthermore it causes direct hepatocyte damage. In patients who consume alcohol over a long period, there is a modification of gut microbiota and, in particular, an increment of Gram negative bacteria. This causes endotoxemia and hyperactivation of the immune system. Endotoxin is a constituent of Gram negative bacteria cell walls. Two types of receptors, cluster of differentiation 14 and Toll-like receptors-4, present on Kupffer cells, recognize endotoxins. Several studies have demonstrated the importance of gut-liver axis and new treatments have been studied in recent years to reduce progression of ALD modifying gut microbiota. It has focused attention on antibiotics, prebiotics, probiotics and synbiotics.

Age-related changes in small intestinal mucosa epithelium architecture and epithelial tight junction in rat models

BACKGROUND AND AIMS

Functions of the intestinal mucosal barrier are often impaired in the elderly and are closely associated with many age-related diseases. However, mechanisms by which aging influences intestinal barrier function still remain unclear. The aim of this study was to investigate age-related changes in small intestinal morphology, bacteria contents and expression of epithelial tight junction (TJ) proteins.

METHODS

Thirty Sprague-Dawley rats were divided into groups: young (3 months), adult (12 months), and old (24 months). The small intestinal mucosal architecture and TJ of intestinal epithelial cells were examined by light microscopy and transmission electron microscopy. Jejunum and cecum contents were cultured to identify and measure bacterial species. mRNA expression of Zonula occludens-1 (ZO-1) and occludin were measured by semi-quantitative RT-PCR. Protein expression of ZO-1 and occludin were detected by immunohistochemistry and Western blot.

RESULTS

Normal ileum villi, which were thick and regularly arranged, though increasingly scattered and atrophic in character with shorter and narrower dimensions (P < 0.01), were observed in old rats, along with an elevated number of Gram-positive and Gram-negative bacteria in the jejunum. The TJs of intestinal epithelial cells, as detected by transmission electron microscopy, were wider and discontinuous in old rats. Age-induced down-regulation of mRNA expression and decreased protein expression of ZO-1 and occludin were observed in the ileum (P < 0.01).

CONCLUSIONS

Our study indicated that age-related intestinal barrier dysfunction may be associated with mucosal atrophy, damages to TJ structure, increased small intestine bacteria counts, and decreased epithelial TJ protein.

Jejunoileal bypass as the main procedure in the onset of immune-related conditions: the model of BADAS

Bariatric surgery represents a common approach for the control of severe morbid obesity, reducing caloric intake by modifying the anatomy of the gastrointestinal tract. Following jejunoileal bypass, a large spectrum of complications has been described, with rheumatic manifestation present in up to 20% of cases. Although bowel bypass syndrome, also called blind loop syndrome, is a well-recognized complication of jejunoileal bypass, the same syndrome was recognized in patients who had not had intestinal bypass surgery, and the term the 'bowel-associated dermatosis-arthritis syndrome' (BADAS) was coined. The pathogenesis of BADAS is as yet poorly understood and only few data concerning this issue have been published in the literature. The aim of the present paper is to review the literature and to discuss putative pathogenic mechanisms of BADAS, focusing on the immune system.

Gastrointestinal bacterial overgrowth: pathogenesis and clinical significance

Small intestinal bacterial overgrowth (SIBO) is defined as the presence of an abnormally high number of coliform bacteria in the small bowel. It is associated with a broad range of predisposing small intestinal motility disorders and with surgical procedures that result in bowel stasis. The most common symptoms associated with SIBO include diarrhea, flatulence, abdominal pain and bloating. Quantitative culture of small bowel contents and a variety of indirect tests have been used over the years in an attempt to facilitate the diagnosis of SIBO. The indirect tests include breath tests and biochemical tests based on bacterial metabolism of a variety of substrates. Unfortunately, there is no single valid test for SIBO, and the accuracy of all current tests remains limited due to the failure of culture to be a gold standard and the lack of standardization of the normal bowel flora in the small intestine. Currently, the ideal approach to treat SIBO is to treat the underlying disease, eradicate overgrowth, and address nutritional deficiencies that may be associated with the development of SIBO.

Diarrhoea due to small bowel diseases

Small intestinal diseases are a common, though often overlooked cause of diarrhoeal illness. Fully 1% of the Caucasian population are affected by coeliac disease and a substantial portion of children living in poverty in the developing world are affected by environmental enteropathy. These are but two examples of the many diseases that cause mucosal injury to the primary digestive and absorptive organ in our body. While diarrhoea may be a common, though not universally seen symptom of small bowel mucosal disease, the consequent malabsorption can lead to substantial malnutrition and nutrient deficiencies. The small intestine, unlike the colon, has been relatively inaccessible, and systematic evaluation is often necessary to identify and treat small intestinal mucosal diseases that lead to diarrhoea. Immunodeficiency states, including HIV enteropathy, adult autoimmune enteropathy, drug-associated enteropathy, and tropical sprue continue to occur and require specific therapy. All patients with severe diarrhoea or diarrhoea associated with features suggestive of malabsorption may have a disease of the small intestinal mucosa that requires careful evaluation and targeted management.

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.

Erosive esophagitis may be related to small intestinal bacterial overgrowth

OBJECTIVES

Erosive esophagitis (EE) may be related to small intestinal bacterial overgrowth (SIBO) because gastro-esophageal reflux disease has been a comorbid condition of irritable bowel syndrome (IBS), which has been associated with SIBO. We conducted a pilot study to investigate whether EE was associated with SIBO.

MATERIAL AND METHODS

Twenty-eight patients with EE according to the Los Angeles classification criteria and 29 sex- and age-matched subjects without EE were enrolled. All subjects underwent esophagogastroduodenoscopy and a lactulose hydrogen breath test. A peak of H₂ values >20 ppm above the basal value after 10 g of lactulose ingestion was considered abnormal and suggestive of SIBO.

RESULTS

Abnormal lactulose hydrogen breath test results were found in 67% of EE patients, as compared with 37% in the control group; the difference was statistically significant (p = 0.024). Among the subjects without IBS, subjects with EE and controls had 65% and 31% abnormal lactulose hydrogen breath test results, respectively; the difference was also statistically significant (p = 0.032).

CONCLUSIONS

Subjects with EE had a higher prevalence of SIBO, as assessed by the lactulose hydrogen breath test, with respect to a control group. These findings may suggest that EE is associated with SIBO.

Functional abdominal pain and irritable bowel syndrome in children and adolescents

Functional abdominal pain (FAP) and irritable bowel syndrome (IBS) are both associated with recurrent abdominal pain and are among the most commonly diagnosed medical problems in pediatrics. The majority of patients with mild complaints improve with reassurance and time. For a distinct subset of patients with more severe and disabling illness, finding effective treatment for these disorders remains a challenge. Based on the biopsychosocial model of functional disease, the Rome III criteria have helped frame FAP and IBS in terms of being a positive diagnosis and not a diagnosis of exclusion. However, the lack of a single, proven intervention highlights the complex interplay of pathologic mechanisms likely involved in the development of childhood FAP and IBS and the need for a multidisciplinary, integrated approach. This article discusses the epidemiology, proposed mechanisms, clinical approach and therapeutic options for the management of FAP and IBS in children and adolescents.

Clinical predictors of small intestinal bacterial overgrowth by duodenal aspirate culture

BACKGROUND

There has been increasing interest in small intestinal bacterial overgrowth (SIBO) after reports of a link with irritable bowel syndrome (IBS), yet our understanding of this entity is limited.

AIM

Our aim was to estimate the yield of patients undergoing duodenal aspirate culture, and to identify symptoms and features that predict SIBO.

METHODS

A medical chart review of patients who had undergone duodenal aspirate culture at an academic medical centre in 2003 was performed to record clinical characteristics and culture results. The associations between aspirate results and symptoms, medical diagnoses and medication use were assessed using logistic regression.

RESULTS

A total of 675 patients had available aspirate results. Mean age of the sample was 53 (s.d. 17) and 443 (66%) were female patients. Overall, 8% of aspirates were positive for SIBO; 2% of IBS patients had SIBO. Older age, steatorrhoea and narcotic use were associated with SIBO (P < 0.05). PPI use was not associated with SIBO, but was associated with bacterial growth not meeting criteria for SIBO (P < 0.05). Inflammatory bowel disease (IBD), small bowel diverticula and pancreatitis were positively associated with an abnormal duodenal aspirate (P < 0.05), but other conditions including IBS were not associated with SIBO.

CONCLUSION

Older age, steatorrhoea, narcotic use, IBD, small bowel diverticula and pancreatitis were associated with small intestinal bacterial overgrowth based on abnormal duodenal aspirate culture results. However, no clear associations of true small intestinal bacterial overgrowth with IBS or PPI use were detected, in contrast to recent speculation.

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

OBJECTIVE AND BACKGROUND

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.

METHODOLOGY

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.

RESULTS

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).

CONCLUSIONS

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.

Small intestinal bacterial overgrowth and lactose intolerance contribute to irritable bowel syndrome symptomatology in Pakistan

BACKGROUND /AIM: The symptoms of irritable bowel syndrome resemble those of small intestinal bacterial overgrowth (SIBO). The aim of this study was to determine the frequency of SIBO and lactose intolerance (LI) occurrence in patients with diarrhea-predominant irritable bowel syndrome (IBS-D) according to Rome III criteria.

PATIENTS AND METHODS

In this retrospective case-control study, patients over 18 years of age with altered bowel habit, bloating, and patients who had lactose Hydrogen breath test (H 2 BT) done were included. The "cases" were defined as patients who fulfill Rome III criteria for IBS-D, while "controls" were those having chronic nonspecific diarrhea (CNSD) who did not fulfill Rome III criteria for IBS-D. Demographic data, predominant bowel habit pattern, concurrent use of medications, etc., were noted.

RESULTS

Patients with IBS-D were 119 (51%) with a mean age of 35 ± 13 years, while those with CNSD were 115 (49%) with mean age 36 ± 15 years. Patients in both IBS-D and CNSD were comparable in gender, with male 87 (74%) and female 77 (64%). SIBO was documented by lactose H₂BT in 32/234 (14%) cases. It was positive in 22/119 (19%) cases with IBS-D, while 10/115 (9%) cases had CNSD (P = 0.03). LI was positive in 43/234 (18%) cases. Of these, 25/119 (21%) cases had IBS-D and 18/115 (16%) cases had CNSD (P = 0.29).

CONCLUSION

SIBO was seen in a significant number of our patients with IBS-D. There was no significant age or gender difference in patients with or without SIBO.

Small intestinal bacterial overgrowth in irritable bowel syndrome: are there any predictors?

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is a condition in which excessive levels of bacteria, mainly the colonic-type species are present in the small intestine. Recent data suggest that SIBO may contribute to the pathophysiology of Irritable bowel syndrome (IBS). The purpose of this study was to identify potential predictors of SIBO in patients with IBS.

METHODS

Adults with IBS based on Rome II criteria who had predominance of bloating and flatulence underwent a glucose breath test (GBT) to determine the presence of SIBO. Breath samples were obtained at baseline and at 30, 45, 60, 75 and 90 minutes after ingestion of 50 g of glucose dissolved in 150 mL of water. Results of the glucose breath test, which measures hydrogen and methane levels in the breath, were considered positive for SIBO if 1) the hydrogen or methane peak was >20 ppm when the baseline was <10 ppm, or 2) the hydrogen or methane peak increased by 12 ppm when baseline was >or=10 ppm.

RESULTS

Ninety-eight patients were identified who underwent a GBT (mean age, 49 y; 78% female). Thirty-five patients (36%) had a positive GBT result suggestive of SIBO. A positive GBT result was more likely in patients >55 years of age (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.4-9.0) and in females (OR, 4.0; 95% CI, 1.1-14.5). Hydrogen was detected more frequently in patients with diarrhea-predominant IBS (OR, 8; 95% CI, 1.4-45), and methane was the main gas detected in patients with constipation-predominant IBS (OR, 8; 95% CI, 1.3-44). There was no significant correlation between the presence of SIBO and the predominant bowel pattern or concurrent use of tegaserod, proton pump inhibitors, or opiate analgesics.

CONCLUSIONS

Small intestinal bacterial overgrowth was present in a sizeable percentage of patients with IBS with predominance of bloating and flatulence. Older age and female sex were predictors of SIBO in patients with IBS. Identification of possible predictors of SIBO in patients with IBS could aid in the development of successful treatment plans.

Rifaximin: a unique gastrointestinal-selective antibiotic for enteric diseases

PURPOSE OF REVIEW

Rifaximin is gaining attention for its potential activity in a multitude of gastrointestinal diseases. We review the unique pharmaceutical properties of this antibiotic and the published evidence in the literature regarding the use of rifaximin for different gastrointestinal disorders.

RECENT FINDINGS

Rifaximin is a gastrointestinal-selective antibiotic with a broad spectrum of antimicrobial activity, an excellent safety profile, minimal drug interactions, and negligible impact on the intestinal microbiome. Rifaximin is currently approved in the United States for the treatment of travelers' diarrhea caused by noninvasive diarrheagenic Escherichia coli and is approved in more than 30 other countries for a variety of gastrointestinal disorders. Considerable research with this medication has been conducted for the treatment and prevention of travelers' diarrhea, the treatment of portal systemic encephalopathy, Clostridium difficile infection, small bowel intestinal overgrowth, irritable bowel syndrome, inflammatory bowel disease, pouchitis, and colonic diverticular disease.

SUMMARY

Rifaximin is effective for the treatment of travelers' diarrhea and can be considered as the treatment of choice for uncomplicated travelers' diarrhea. When invasive travelers' diarrhea pathogens are suspected, an alternative antibiotic should be administered. Rifaximin appears promising as a chemoprophylaxis for travelers' diarrhea and as a treatment of portal systemic encephalopathy. This antibiotic may be effective for other gastrointestinal diseases, but more well designed clinical studies are needed to confirm its efficacy for these off-label indications. Future studies will determine whether the development of significant bacterial resistance will limit rifaximin use.

Prevalence of small intestinal bacterial overgrowth in children with irritable bowel syndrome: a case-control study

OBJECTIVE

To assess the prevalence of small intestinal bacterial overgrowth (SIBO) in children affected by irritable bowel syndrome (IBS).

STUDY DESIGN

Consecutive children affected by IBS according to Rome II criteria (n = 43) were enrolled at the Gemelli Hospital, Catholic University of Rome. The control population (n = 56) consisted of healthy subjects without IBS symptoms, similar to patients for age, sex, and social background. All subjects underwent lactulose/methane breath test (LBT) to assess small intestinal bacterial overgrowth.

RESULTS

The prevalence of abnormal LBT result was significantly higher in patients with IBS (65%, 28/43) with respect to control subjects (7%, 4/56; OR 3.9, 95% CI 7.3-80.1, P < .00001). Patients with abnormal LBT showed a trend toward a worse visual analog scale score with respect to children with IBS without SIBO, but a significant statistical difference was observed only for bloating.

CONCLUSIONS

Results from this study suggest a significant epidemiologic association between SIBO and IBS in childhood. Placebo-controlled interventional studies with antibiotics used to treat bacterial overgrowth are warranted to clarify the real impact of the disease on IBS symptoms.

Rifaximin pharmacology and clinical implications

Rifaximin is a semisynthetic, rifamycin-based non-systemic antibiotic, with a low gastrointestinal absorption and a good antibacterial activity. The antibacterial action covers Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Its antimicrobial action is based on its property to bind to the beta-subunit of bacterial DNA-dependent RNA polymerase inhibiting, thereby, the bacterial RNA synthesis. Rifaximin contributes to restore gut microflora imbalance, becoming an important therapeutic agent in several organic and functional gastrointestinal diseases such as hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. This antibiotic has the advantage of low microbial resistance and few systemic adverse events and is safe in all patient populations, including young children.

Prevalence of small intestine bacterial overgrowth diagnosed by quantitative culture of intestinal aspirate in celiac disease

BACKGROUND AND AIM

A recent study using lactulose hydrogen-breath testing suggests that small intestine bacterial overgrowth (SIBO) is a common cause of nonresponsive celiac disease (CD). The prevalence of SIBO in CD diagnosed by quantitative culture of intestinal aspirate is unknown. The aim of this study is to evaluate the prevalence and significance of SIBO in CD based on the results of quantitative culture of intestinal aspirate.

METHODS

We studied patients with CD in whom culture of intestinal aspirate was evaluated for the presence of anaerobes and aerobes. Bacterial overgrowth was diagnosed if culture demonstrated >10 colony forming units/mL. The causes of nonresponsive CD were investigated.

RESULTS

We included 149 biopsy-confirmed CD patients. The intestinal aspirate was collected in 79 (53%) patients with nonresponsive CD, 47 (32%) as initial work-up for malabsorption, and in 23 (15%) asymptomatic treated CD. SIBO was diagnosed in 14 (9.3%). Nine (11%) with nonresponsive CD, 5 (11%) at initial work-up for malabsorption, and 0 in asymptomatic treated CD. Patients with a positive culture had evidence of worse malabsorption. A coexistent disorder was found in 67% of patients with both nonresponsive CD and bacterial overgrowth.

CONCLUSIONS

The prevalence of SIBO diagnosed by quantitative culture of intestinal aspirate was 9.3% in patients with CD. Patients with symptomatic treated or untreated CD were affected. SIBO may coexist with other disorders associated with nonresponsive CD.

Chronic pouchitis is not related to small intestine bacterial overgrowth

BACKGROUND

Restorative ileal pouch-anal anastomosis (IPAA) potentially may lead to upper gastrointestinal tract motility disturbances. In addition, a bacterial etiology of IPAA complication-pouchitis-has been suggested. The oro-anal transit time is significantly reduced in this patient group. Therefore, we investigated the hypothesis if IPAA constitutes a significant risk for small intestine bacterial overgrowth (SIBO).

METHODS

Twenty-eight patients age 23-71 years with IPAA operated due to ulcerative colitis without subjective symptoms of pouchitis were evaluated as outpatients according to the prescheduled follow-up after operation and included in the study. The modified Pouchitis Disease Activity Index (PDAI) was determined in all IPAA patients, including clinical, endoscopic, and histopathological (Moskowitz criteria) parameters. In addition, anorectal manometry was performed. The presence of SIBO was determined with the use of a glucose breath test (GBT).

RESULTS

In 1 subject (3.6%) an abnormal GBT result was recorded consistent with SIBO. In addition, 2 borderline values (7.1%) were documented. Both patients with SIBO as subjects with borderline values presented with low PDAI values. All patients with PDAI >7 had normal GBT results. In patients with SIBO the maximal tolerated rectal volume was significantly higher than in subjects without SIBO (P < 0.007). Similarly, the PDAI value was significantly lower (P < 0.014).

CONCLUSIONS

Asymptomatic chronic pouchitis is not related to SIBO. However, excessive colonization of the small intestine does occur in some IPAA patients and needs to be kept in the differential diagnosis.

Rifaximin versus other antibiotics in the primary treatment and retreatment of bacterial overgrowth in IBS

PURPOSE

Previous studies demonstrate improvement in IBS after antibiotic therapy, with the greatest efficacy seen with the antibiotic, rifaximin. The purpose of this study was to compare the efficacy of rifaximin in both the treatment and retreatment of IBS.

METHODS

A retrospective chart review was conducted on Rome I-positive IBS patients. Charts were reviewed to evaluate all antibiotic treatments (rifaximin, neomycin, doxycycline, amoxicillin/clavulanate, and ciprofloxacin), even those predating 1 July 2004. Data collection included symptoms, breath test results (pre- and post-treatment), antibiotics used, and clinical response to individual antibiotic treatments before and after rifaximin availability in the USA.

RESULTS

Out of 98 eligible charts, 84 patients received one course of rifaximin. Fifty of these (60%) had a follow-up breath test. Among these, 31 (62%) were clinical responders and 19 (38%) were nonresponders. Of 31 responders, 25 (81%) had a normal follow-up breath test compared with only 3 of the 19 nonresponders (16%) (P < 0.001). Of participants given rifaximin, 69% (58 out of 84) had a clinical response compared with only 38% (9 out of 24) with neomycin (P < 0.01) and 44% (27 out of 61) with all non-rifaximin antibiotics (P < 0.01). Rifaximin was used as retreatment on 16 occasions, and all patients improved.

CONCLUSIONS

Rifaximin is more effective than other antibiotics in the treatment and retreatment of IBS.

Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity

The presence of methane on lactulose breath test among irritable bowel syndrome (IBS) subjects is highly associated with the constipation-predominant form. Therefore, we set out to determine whether methane gas can alter small intestinal motor function. In dogs, small intestinal fistulae were created to permit measurement of intestinal transit. Using a radiolabel, we evaluated transit during infusion of room air and subsequently methane. In this model, small intestinal infusion of methane produced a slowing of transit in all dogs by an average of 59%. In a second experiment, guinea pig ileum was pinned into an organ bath for the study of contractile activity in response to brush strokes applied to the mucosa. The force of contraction was measured both orad and aborad to the stimulus. The experiment was repeated while the bath was gassed with methane. Contractile activities orad and aborad to the stimulus were significantly augmented by methane compared with room air (P < 0.05). In a third experiment, humans with IBS who had undergone a small bowel motility study were compared such that subjects who produced methane on lactulose breath test were compared with those producing hydrogen. The motility index was significantly higher in methane-producing IBS patients (1,851 +/- 861) compared with hydrogen producers (1,199 +/- 301) (P < 0.05). Therefore, methane, a gaseous by-product of intestinal bacteria, slows small intestinal transit and appears to do so by augmenting small bowel contractile activity.

Transient lactose malabsorption in patients affected by symptomatic uncomplicated diverticular disease of the colon

Lactose malabsorption (LM) may be secondary to several small bowel diseases, and small intestinal overgrowth (SIBO) may be one of them. We looked for a correlation between symptomatic diverticular disease of the colon and LM and assessed whether this correlation may be related to SIBO. Ninety consecutive patients (pts; 39 males, 51 females; mean age, 67.2 years; range, 32-91 years) affected by symptomatic uncomplicated diverticular disease of the colon were evaluated to assess orocecal transit time (OCTT), SIBO, and LM by lactulose and lactose H2 breath test (H2-BT) at entry and after 8 weeks of treatment. OCTT was delayed in 67 of 90 pts (74.44%). Fifty-three of 90 pts (58.88%) showed SIBO, and OCTT was normal in 23 of 90 pts (25.56%). LM was diagnosed in 59 of 90 pts (65.55%): 49 of 59 (71.74%) were simultaneously affected by SIBO and delayed OCTT (and thus 49 of 53 pts [92.45%] with delayed OCTT and SIBO were affected by LM); 3 of 59 pts (5.09%) showed only delayed OCTT; 7 of 59 pts (11.86%) did not show either SIBO or delayed OCTT. The association of LM and SIBO was statistically significant (P < 0.001). Seventy-nine of 86 pts (91.86%) showed normal OCTT, while OCTT remained prolonged but shorter in the remaining 7 pts (8.14%). SIBO was eradicated in all pts completing the study, while a new lactulose H2-BT showed persistence of SIBO in one pt with recurrence of symptomatic diverticular disease. Forty-seven of 59 pts (79.66%) had a normal lactose H2-BT (P < 0.002), while 12 of 59 pts (20.34%) showed persistence of LM. LM disappeared in 46 of 49 pts (93.88%) concurrently with normalization of OCTT and eradication of SIBO (P < 0.002); it also disappeared in 1 of 3 pts (33.33%) previously affected by delayed OCTT (without SIBO) and LM concurrently with normalization of OCTT. On the contrary, it persisted in all pts with normal OCTT and absence of SIBO. Moreover, it persisted also in the pt with recurrence of symptomatic diverticular disease and persistence of SIBO. In conclusion, most pts affected by symptomatic uncomplicated diverticular disease of the colon showed LM, and in more than 70% of cases it disappeared after successful treatment of the colonic disease.

Hydrogen glucose breath test to detect small intestinal bacterial overgrowth: a prevalence case-control study in irritable bowel syndrome

BACKGROUND

Studies assessing the prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome gave contrasting results. Differences in criteria to define irritable bowel syndrome patients and methods to assess small intestinal bacterial overgrowth may explain different results. Moreover, no data exist on small intestinal bacterial overgrowth prevalence in a significant population of healthy non-irritable bowel syndrome subjects.

AIM

To assess the prevalence of small intestinal bacterial overgrowth by glucose breath test in patients with irritable bowel syndrome symptoms with respect to a consistent control group.

METHODS

Consecutive patients with irritable bowel syndrome according to Rome II criteria were enrolled. The control population consisted of 102 sex- and age-matched healthy subjects without irritable bowel syndrome symptoms. All subjects underwent glucose breath test. A peak of H2 values >10 p.p.m above the basal value after 50 g of glucose ingestion was considered suggestive of small intestinal bacterial overgrowth.

RESULTS

A total of 65 irritable bowel syndrome patients and 102 healthy controls were enrolled. Positivity to glucose breath test was found in 31% of irritable bowel syndrome patients with respect to 4% in the control group, the difference between groups resulting statistically significant (OR: 2.65; 95% CI: 3.5-33.7, P < 0.00001).

CONCLUSIONS

The present case-control study showed an epidemiological association between irritable bowel syndrome and small intestinal bacterial overgrowth. Placebo-controlled small intestinal bacterial overgrowth-eradication studies are necessary to clarify the real impact of small intestinal bacterial overgrowth on irritable bowel syndrome symptoms.

Small Bowel Bacterial Overgrowth in Symptomatic Older People: Can It Be Diagnosed Earlier?

BACKGROUND/OBJECTIVES

In older people, small bowel bacterial overgrowth syndrome may be a common, but under-diagnosed, cause of diarrhoea and nutrient malabsorption. We aim to determine which clinical features and baseline laboratory investigations indicate a high likelihood of small bowel bacterial overgrowth as defined by a positive glucose breath test.

METHODS

A retrospective analysis of records for all patients referred for glucose breath test over a 6-year period to a teaching hospital.

RESULTS

Out of 197 referrals, 168 patient records were located and analysed (62 male, 106 female; median age 65). Patient characteristics predictive of a positive glucose breath test were: increasing age (p < 0.01), low serum vitamin B12 (p = 0.02), low serum albumin (p = 0.03), previous partial gastrectomy (p < 0.01), previous right hemi-colectomy (p < 0.01), presence of small bowel diverticulae (p = 0.01) and concurrent use of a proton pump inhibitor (p < 0.01). 52.5% (n = 21/40) of patients studied who were over 75 years old versus 21.8% (n = 28/128) of those under 75 years old had a positive glucose breath test (p < 0.01). The median time to diagnosis, from first hospital visit to positive glucose breath test, was 39 weeks.

CONCLUSIONS

There is often a significant delay in diagnosis of small bowel bacterial overgrowth. We suggest that this diagnosis should be considered earlier in the investigative algorithm in older patients with indicative symptoms and a predisposing factor (including previous partial gastrectomy, previous right hemi-colectomy, small bowel diverticulae or use of a proton pump inhibitor) or concurring laboratory indices (low vitamin B12 or albumin).

Rifaximin dose-finding study for the treatment of small intestinal bacterial overgrowth

BACKGROUND

Few controlled studies assessing choice and duration of antibiotic therapy for small intestinal bacterial overgrowth are available.

AIM

To assess efficacy, safety and tolerability of different doses of rifaximin, a broad spectrum non-absorbable antibiotic, for intestinal bacterial overgrowth eradication.

METHODS

We enrolled 90 consecutive patients affected by small intestinal bacterial overgrowth. The presence of small intestinal bacterial overgrowth was based on the occurrence of a rise of H2 values >12 p.p.m. above the basal value after 50 g glucose ingestion. Patients were randomized in three 7-day treatment groups: rifaximin 600 mg/day (group 1); rifaximin 800 mg/day (group 2) and rifaximin 1200 mg/day (group 3). Glucose breath test was reassessed 1 month after the end of therapy. Compliance to the treatment and incidence of side-effects were also evaluated.

RESULTS

No drop-outs were observed in the three groups. Glucose breath test normalization rate was significantly higher in group 3 (60%) with respect to group 1 (17%; P < 0.001) and group 2 (27%, P < 0.01). No significant differences in patient compliance and incidence of side-effects were found among groups.

CONCLUSIONS

Higher doses of rifaximin lead to a significant gain in terms of therapeutic efficacy in small intestinal bacterial overgrowth eradication without increasing the incidence of side-effects.

Abnormal breath tests to lactose, fructose and sorbitol in irritable bowel syndrome may be explained by small intestinal bacterial overgrowth

BACKGROUND

Small intestinal bacterial overgrowth and sugar malabsorption (lactose, fructose, sorbitol) may play a role in irritable bowel syndrome. The lactulose breath test is a reliable and non-invasive test for the diagnosis of small intestinal bacterial overgrowth. The lactose, fructose and sorbitol hydrogen breath tests are widely used to detect specific sugar malabsorption.

AIM

To assess the extent to which small intestinal bacterial overgrowth may influence the results of hydrogen sugar breath tests in irritable bowel syndrome patients.

METHODS

We enrolled 98 consecutive irritable bowel syndrome patients. All subjects underwent hydrogen lactulose, lactose, fructose and sorbitol hydrogen breath tests. Small intestinal bacterial overgrowth patients were treated with 1-week course of antibiotics. All tests were repeated 1 month after the end of therapy.

RESULTS

A positive lactulose breath test was found in 64 of 98 (65%) subjects; these small intestinal bacterial overgrowth patients showed a significantly higher prevalence of positivity to the lactose breath test (P < 0.05), fructose breath test (P < 0.01) and sorbitol breath test (P < 0.01) when compared with the small intestinal bacterial overgrowth-negatives. Small intestinal bacterial overgrowth eradication, as confirmed by negative lactulose breath test, caused a significant reduction in lactose, fructose and sorbitol breath tests positivity (17% vs. 100%, 3% vs. 62%, and 10% vs. 71% respectively: P < 0.0001).

CONCLUSIONS

In irritable bowel syndrome patients with small intestinal bacterial overgrowth, sugar breath tests may be falsely abnormal. Eradication of small intestinal bacterial overgrowth normalizes sugar breath tests in the majority of patients. Testing for small intestinal bacterial overgrowth should be performed before other sugar breath tests tests to avoid sugar malabsorption misdiagnosis.