Small intestinal bacterial overgrowth mimicking acute flare as a pitfall in patients with Crohn's Disease

Association between Gut Dysbiosis and the Occurrence of SIBO, LIBO, SIFO and IMO

Gut microbiota is the aggregate of all microorganisms in the human digestive system. There are 1014 CFU/mL of such microorganisms in the human body, including bacteria, viruses, fungi, archaea and protozoa. The Firmicutes and Bacteroidetes bacteria phyla comprise 90% of the human gut microbiota. The microbiota support the healthy functioning of the human body by helping with digestion (mainly via short-chain fatty acids and amino acids) and producing short-chain fatty acids. In addition, it exhibits many physiological functions, such as forming the intestinal epithelium, intestinal integrity maintenance, the production of vitamins, and protection against pathogens. An altered composition or the number of microorganisms, known as dysbiosis, disrupts the body's homeostasis and can lead to the development of inflammatory bowel disease, irritable bowel syndrome, and metabolic diseases such as diabetes, obesity and allergies. Several types of disruptions to the gut microbiota have been identified: SIBO (Small Intestinal Bacterial Overgrowth), LIBO (Large Intestinal Bacterial Overgrowth), SIFO (Small Intestinal Fungal Overgrowth), and IMO (Intestinal Methanogen Overgrowth). General gastrointestinal problems such as abdominal pain, bloating, gas, diarrhoea and constipation are the main symptoms of dysbiosis. They lead to malabsorption, nutrient deficiencies, anaemia and hypoproteinaemia. Increased lipopolysaccharide (LPS) permeability, stimulating the inflammatory response and resulting in chronic inflammation, has been identified as the leading cause of microbial overgrowth in the gut. The subject literature is extensive but of limited quality. Despite the recent interest in the gut microbiome and its disorders, more clinical research is needed to determine the pathophysiology, effective treatments, and prevention of small and large intestinal microbiota overgrowth. This review was designed to provide an overview of the available literature on intestinal microbial dysbiosis (SIBO, LIBO, SIFO and IMO) and to determine whether it represents a real threat to human health.

Impact of Small Intestinal Bacterial Overgrowth in Patients with Inflammatory Bowel Disease and Other Gastrointestinal Disorders-A Retrospective Analysis in a Tertiary Single Center and Review of the Literature

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is often found in patients with gut dysbiosis such as irritable bowel syndrome. Recently, the association of SIBO and inflammatory bowel disease (IBD) has been described in some cases. While clinical symptoms might be similar in IBD and SIBO, treatment is quite different for both diseases. Therefore, the differentiation between SIBO or a flare in IBD patients is key to optimizing treatment for these patients.

METHODS

We retrospectively investigated our patients with IBD receiving a glucose breath test for SIBO and correlated the results with the clinical symptoms (clinical remission or active disease).

RESULTS

128 patients with the diagnosis "colitis" were analyzed in our cohort. Fifty-three (41.4%) patients had Crohn's disease and 22 (17.2%) patients were suffering from ulcerative colitis. Seventy-four (57.8%) were female and 54 (42.2%) were male patients. A total of 18 (14.1%) patients had a positive testing for SIBO. Eleven (61.1%) cases were associated with CD patients and two (11.1%) with UC. IBD patients in clinical remission had a positive SIBO in six (19.4%) cases, while IBD patients with active disease were positive in nine (15.3%) cases. The proportion of positive SIBO in active IBD patients was higher; however, it did not reach significance. Older age was a risk factor for SIBO in patients with CD (p < 0.003).

CONCLUSIONS

In our study, we could show that an increased amount of SIBO was found in IBD patients and was especially more frequent in patients with CD than in those with UC. In UC patients, SIBO rates were not different to patients with other gastrointestinal diseases investigated (e.g., infectious colitis, collagenous colitis, or irritable bowel syndrome). In active IBD, positive SIBO was detected more often numerically compared to quiescent disease; however, due to the low number of patients included, it was not significant. However, older age was a significant risk factor for SIBO in patients with CD. SIBO is of clinical relevance in the vulnerable patient cohort with IBD, and its real prevalence and impact needs to be investigated in further and larger clinical trials.

Show Me What You Have Inside-The Complex Interplay between SIBO and Multiple Medical Conditions-A Systematic Review

The microbiota, as a complex of microorganisms in a particular ecosystem, is part of the wider term-microbiome, which is defined as the set of all genetic content in the microbial community. Imbalanced gut microbiota has a great impact on the homeostasis of the organism. Dysbiosis, as a disturbance in bacterial balance, might trigger or exacerbate the course of different pathologies. Small intestinal bacterial overgrowth (SIBO) is a disorder characterized by differences in quantity, quality, and location of the small intestine microbiota. SIBO underlies symptoms associated with functional gastrointestinal disorders (FGD) as well as may alter the presentation of chronic diseases such as heart failure, diabetes, etc. In recent years there has been growing interest in the influence of SIBO and its impact on the whole human body as well as individual systems. Therefore, we aimed to investigate the co-existence of SIBO with different medical conditions. The PubMed database was searched up to July 2022 and we found 580 original studies; inclusion and exclusion criteria let us identify 112 eligible articles, which are quoted in this paper. The present SIBO diagnostic methods could be divided into two groups-invasive, the gold standard-small intestine aspirate culture, and non-invasive, breath tests (BT). Over the years scientists have explored SIBO and its associations with other diseases. Its role has been confirmed not only in gastroenterology but also in cardiology, endocrinology, neurology, rheumatology, and nephrology. Antibiotic therapy could reduce SIBO occurrence resulting not only in the relief of FGD symptoms but also manifestations of comorbid diseases. Although more research is needed, the link between SIBO and other diseases is an important pathway for scientists to follow.

Recommendations for Standardizing Clinical Trial Design and Endoscopic Assessment in Postoperative Crohn's Disease

BACKGROUND

The lack of standardized methods for clinical trial design and disease activity assessment has contributed to an absence of approved medical therapies for the prevention of postoperative Crohn's disease (CD). We developed recommendations for regulatory trial design for this indication and for endoscopic assessment of postoperative CD activity.

METHODS

An international panel of 19 gastroenterologists was assembled. Modified Research and Development/University of California Los Angeles methodology was used to rate the appropriateness of 196 statements using a 9-point Likert scale in 2 rounds of voting. Results were reviewed and discussed between rounds.

RESULTS

Inclusion of patients with a history of completely resected ileocolonic CD in regulatory clinical trials for the prevention of postoperative recurrence was appropriate. Given the absence of approved medical therapies, a placebo-controlled design with a primary end point of endoscopic remission at 52 weeks was appropriate for drug development for this indication; however, there was uncertainty regarding the appropriateness of a coprimary end point of symptomatic and endoscopic remission and the use of currently available patient-reported outcome measures. The modified Rutgeerts Score, endoscopic assessment of the anastomosis, and a minimum of 5cm of neoterminal ileum were also appropriate; although the appropriateness of other indices including the Simple Endoscopic Score for CD for endoscopic assessment of postoperative CD activity was uncertain.

CONCLUSIONS

A framework for regulatory trial design for the prevention of postoperative CD recurrence and endoscopic assessment of disease activity has been developed. Research to empirically validate end points for these trials is needed.

Small Intestinal Bacterial Overgrowth-Pathophysiology and Its Implications for Definition and Management

The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.

Advances in the Comprehensive Management of Postoperative Crohn's Disease

Patients with postoperative Crohn's disease are difficult to manage because of their risk of experiencing a more severe course, multiple symptom confounders, and poor sensitivity of symptomatic remission to rule out intestinal inflammation. In this group, data are lacking on biologic therapeutic efficacy, and recommendations are lacking for those with multiple medication failures. Novel noninvasive testing can simultaneously exclude alternate causes of symptoms (serum C4, fecal fat, small intestinal bowel overgrowth breath testing) and assess intestinal inflammation (fecal calprotectin, endoscopic healing index). In addition, endoscopy-based disease activity assessment and management are required. Endoscopy should be performed within 6 months of surgery, and aggressive disease activity monitoring can be considered with colonoscopy every 1-2 years subsequently to ensure late recurrence is detected. Patients with multiple resections should be screened for short bowel syndrome. Predictive biomarkers are needed to guide medication selection in this high-risk population. Postoperative prophylactic biologic therapy is prudent for patients with preoperative biologic failure. However, there are no high-quality data to guide which agent should be selected. Selecting biologics with an alternative mechanism of action in those who had failed a biologic with adequate drug concentrations and selection of different agents in those with previous intolerance are reasonable. Significantly more study is required to assess the efficacy of therapies in this setting.

Small intestinal bacterial overgrowth in patients with inflammatory bowel disease: A case-control study

BACKGROUND

Though small intestinal bacterial overgrowth (SIBO) is known in inflammatory bowel disease (IBD), the data on it are scanty and have limitations.

METHODS

Data on IBD patients undergoing glucose hydrogen breath test (GHBT) were retrospectively analyzed to evaluate the frequency and risk factors of SIBO in IBD compared to 66 healthy controls.

RESULTS

Patients with IBD (n=86; 45 ulcerative colitis [UC] and 41 Crohn's disease [CD]) more often had SIBO on GHBT than the healthy subjects (16/86 [18.6%] vs. 1/66 [1.5%]; p=0.002). SIBO was commoner among patients with CD than UC (14/41 [34.1%] vs. 2/45 [4.4%]; p=0.001). The frequency of SIBO among UC patients was comparable to healthy subjects (2/45 [4.4%] vs. 1/66 [1.5%]; p=not significant [NS]). Patients with CD than those with UC had higher values of maximum breath hydrogen and a greater area under the curve for breath hydrogen. Other factors associated with SIBO included female gender (11/16 [68.8%] with vs. 21/70 [30%] without SIBO; p=0.003), and having undergone surgery (8/16 [50%] vs. 6/70 [8.6%]; p=0.0002). SIBO patients had lower levels of total serum protein and albumin than those without SIBO (6.2 ± 1.5 g/dL vs. 7.0 ± 0.9 g/dL, respectively; p=0.009 and 3.5 ± 0.9 g/dL vs. 4.0 ± 0.6 g/dL, respectively; p=0.02). CD, female gender, and surgery for IBD tended to be the independent factors associated with SIBO among IBD patients on multivariate analysis.

CONCLUSIONS

Patients with IBD, particularly CD, female, and those having undergone surgery, have a higher risk of SIBO than the healthy controls.

Bacterial Translocation as Inflammatory Driver in Crohn's Disease

Crohn’s disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract responsible for intestinal lesions. The multifactorial etiology attributed to CD includes a combination of environmental and host susceptibility factors, which result in an impaired host–microbe gut interaction. Bacterial overgrowth and dysbiosis, increased intestinal barrier permeability, and altered inflammatory responses in patients with CD have been described in the past. Those events explain the pathogenesis of luminal translocation of bacteria or its products into the blood, a frequent event in CD, which, in turn, favors a sustained inflammatory response in these patients. In this review, we navigate through the interaction between bacterial antigen translocation, permeability of the intestinal barrier, immunologic response of the host, and genetic predisposition as a combined effect on the inflammatory response observed in CD. Several lines of evidence support that translocation of bacterial products leads to uncontrolled inflammation in CD patients, and as a matter of fact, the presence of gut bacterial genomic fragments at a systemic level constitutes a marker for increased risk of relapse among CD patients. Also, the significant percentage of CD patients who lose response to biologic therapies may be influenced by the translocation of bacterial products, which are well-known drivers of proinflammatory cytokine production by host immune cells. Further mechanistic studies evaluating cellular and humoral immune responses, gut microbiota alterations, and genetic predisposition will help clinicians to better control and personalize the management of CD patients in the future.

The Relationship Between Endoscopic and Clinical Recurrence in Postoperative Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

We aimed to quantify the magnitude of the association between endoscopic recurrence and clinical recurrence [symptom relapse] in patients with postoperative Crohn's disease.

METHODS

Databases were searched to October 2, 2020, for randomised controlled trials [RCTs] and cohort studies of adult patients with Crohn's disease with ileocolonic resection and anastomosis. Summary effect estimates for the association between clinical recurrence and endoscopic recurrence were quantified by risk ratios [RR] and 95% confidence intervals [95% CI]. Mixed-effects meta-regression evaluated the role of confounders. Spearman correlation coefficients were calculated to assess the relationship between these outcomes as endpoints in RCTs. An exploratory mixed-effects meta-regression model with the logit of the rate of clinical recurrence as the outcome and the rate of endoscopic recurrence as a predictor was also evaluated.

RESULTS

In all, 37 studies [N = 4053] were included. For eight RCTs with available data, the RR for clinical recurrence for patients who experienced endoscopic recurrence was 10.77 [95% CI 4.08 to 28.40; GRADE moderate certainty evidence]; the corresponding estimate from 11 cohort studies was 21.33 [95% CI 9.55 to 47.66; GRADE low certainty evidence]. A single cohort study showed a linear relationship between Rutgeerts score and clinical recurrence risk. There was a strong correlation between endoscopic recurrence and clinical recurrence treatment effect estimates as trial outcomes [weighted Spearman correlation coefficient 0.51].

CONCLUSIONS

The associations between endoscopic recurrence and subsequent clinical recurrence lend support to the choice of endoscopic recurrence to monitor postoperative disease activity and as a primary endpoint in clinical trials of postoperative Crohn's disease.

Predictors of Small Intestinal Bacterial Overgrowth in Symptomatic Patients Referred for Breath Testing

Background

Indications for a breath test (BT) are well established in the symptomatic patient with risk factors predisposing them to small intestinal bacterial overgrowth (SIBO). Characteristics and the profile of this population are not well known. Our objective was to study the characteristics of patients undergoing a BT for SIBO and to identify factors associated with a positive BT.

Methods

Retrospective study was conducted from 2012 to 2016 at the neurogastroenterology unit of the Centre Hospitalier de l'Universite de Montreal (CHUM). All patients who completed a BT (lactulose and/or glucose) were included. Demographics and clinical factors were analyzed to identify predictors of positive BT. Type of antibiotic treatment and clinical response were compiled. Groups of patients with (SIBO⁺) and without SIBO (SIBO^-) were also compared.

Results

A total of 136 patients were included in the study (mean age 51.2, range 20 - 80 years; 63% women), and SIBO was detected in 33.8% (n = 46). Both groups were similar in terms of age, body mass index, and gender. SIBO was significantly associated with the presence of abdominal pain (odds ratio (OR) = 4.78; P < 0.05), bloating (OR = 5.39; P < 0.05), smoking (OR = 6.66; P < 0.05), and anemia (OR = 4.08; P < 0.05). No association was identified with gender, age, obesity, and risk factors for SIBO. Antibiotics were used in 43% of patients with a positive BT, but clinical response was not significantly different in the subgroup that received antibiotics versus the subgroup that did not.

Conclusions

The prevalence of SIBO is high in symptomatic patients who underwent breath testing. Abdominal pain, bloating, smoking, and anemia are strongly associated with SIBO. Treatment of SIBO with antibiotics needs to be further investigated to better determine its efficacy on gastrointestinal symptoms.

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

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) appears to be common in patients with Crohn's disease (CD). The rate of SIBO has been estimated at 25%-88% in this setting. However, different demographic, socioeconomic, and disease-related factors may exist between South American and North American or European populations that may limit the generalization of these findings, as the data are mainly derived from North American or European studies.

OBJECTIVE

We studied the prevalence and predictors of SIBO in CD outpatients.

METHODS

In this retrospective study, between June 2011 and June 2016, the medical records of 110 CD patients were assessed for presence of SIBO using the H2/CH4 glucose breath test. Univariate analysis was performed to investigate the potential association between SIBO and demographic, disease-related data, systemic markers of inflammation (C-reactive protein and erythrocyte sedimentation rate).

RESULTS

The SIBO rate was high in CD patients (30%). Patients with and without SIBO were comparable according to demographics, systemic inflammatory biomarkers, and disease characteristics, except to the stricturing phenotype more common in the SIBO-positive CD patients (48.5% vs 19.5%, P=0.001).

CONCLUSION

In Brazilian CD patients, SIBO is a highly prevalent condition. Stricturing phenotype demonstrated association with SIBO. An individualized screening plan followed by the timely treatment for SIBO should be carried out as part of quality of care improvement in CD individuals.

Breath Test Gas Patterns in Inflammatory Bowel Disease with Concomitant Irritable Bowel Syndrome-Like Symptoms: A Controlled Large-Scale Database Linkage Analysis

INTRODUCTION

Breath testing (BT) has gained interest for diagnosing small intestinal bacterial overgrowth (SIBO) in IBD patients with irritable bowel syndrome (IBS) overlap. We aim to characterize the rate of SIBO and BT gas patterns in IBD patients with IBS-like symptoms compared to non-IBD patients.

METHODS

A database of 14,847 consecutive lactulose BTs was developed from patients with IBS-like symptoms between November 2005 and October 2013. BTs were classified as normal, H₂ predominant, CH₄ predominant, and flatline based on criteria established from the literature. BT data linkage with electronic health records and chart review identified IBD patients along with disease phenotype, location, severity, and antibiotic response. Poisson loglinear model evaluated differences in gas patterns between the two groups.

RESULTS

After excluding patients with repeat breath tests, we identified 486 IBD and 10,505 non-IBD patients with at least one BT. Positive BT was present in 57% (n = 264) of IBD patients. Crohn's disease (odds ratio (OR) 0.21, [95% confidence interval (CI) 0.11-0.38]) and ulcerative colitis (OR 0.39, [95% CI 0.22-0.70]) patients were less likely to produce excess CH₄. IBD patients were more likely to have flatline BT (OR 1.82, [95% CI 1.20-2.77]). In IBD patients with SIBO, 57% improved symptomatically with antibiotics.

CONCLUSION

In a cohort of IBD patients with IBS-like symptoms, a high rate of patients had positive BT and symptomatic improvement with antibiotics. In IBD, methanogenesis is suppressed and flatline BT is more frequent, suggesting excess hydrogenotrophic bacteria. These findings suggest methanogenic and hydrogenotrophic microorganisms as potential targets for microbiome-driven biomarkers and therapies.

Breath Tests for the Non-invasive Diagnosis of Small Intestinal Bacterial Overgrowth: A Systematic Review With Meta-analysis

BACKGROUND/AIMS

Small intestinal bacterial overgrowth (SIBO) diagnosis is usually based on non-invasive breath tests (BTs), namely lactulose BT (LBT) and glucose BT (GBT). However, divergent opinions and problems of parameter standardization are still controversial aspects. We aim to perform a meta-analysis to analyze diagnostic performance of LBT/GBT for SIBO diagnosis.

METHODS

We searched in main literature databases articles in which SIBO diagnosis was achieved by LBT/GBT in comparison to jejunal aspirate culture (reference gold standard). We calculated pooled sensitivity, specificity, positive, and negative likelihood ratios and diagnostic odd ratios. Summary receiver operating characteristic curves were drawn and pooled areas under the curve were calculated.

RESULTS

We selected 14 studies. Pooled sensitivity of LBT and GBT was 42.0% and 54.5%, respectively. Pooled specificity of LBT and GBT was 70.6% and 83.2%, respectively. When delta over baseline cut-off > 20 H₂ parts per million (ppm) was used, GBT sensitivity and specificity were 47.3% and 80.9%; when the cutoff was other than and lower than > 20 ppm, sensitivity and specificity were 61.7% and 86.0%. In patients with abdominal surgery history, pooled GBT sensitivity and specificity gave the impression of having a better performance (81.7% and 78.8%) compared to subjects without any SIBO predisposing condition (sensitivity = 40.6% and specificity = 84.0%).

CONCLUSIONS

GBT seems to work better than LBT. A cut-off of delta H2 expired other than and lower than > 20 ppm shows a slightly better result than > 20 ppm. BTs demonstrate the best effectiveness in patients with surgical reconstructions of gastrointestinal tract.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

Longer small bowel segments are resected in emergency surgery for ileocaecal Crohn's disease with a higher ileostomy and complication rate

BACKGROUND

Repeated intestinal resections may have disabling consequences in patients with Crohn's disease even in the absence of short bowel syndrome. Our aim was to evaluate the length of resected small bowel in patients undergoing elective and emergency surgery for ileocolic Crohn's disease.

METHODS

A prospective observational study was conducted on patients undergoing surgery for ileocolonic Crohn's disease in a single colorectal centre from May 2010 to April 2018. The following patients were included: (1) patients with first presentation of ileocaecal Crohn's disease undergoing elective surgery; (2) patients with ileocaecal Crohn's disease undergoing emergency surgery; (3) patients with recurrent Crohn's disease of the distal ileum undergoing elective surgery. The primary outcomes were length of resected small bowel and the ileostomy rate. Operating time, complications and readmissions within 30 days were the secondary outcomes.

RESULTS

One hundred and sixty-eight patients were included: 87 patients in the elective primary surgery group, 50 patients in the emergency surgery group and 31 in the elective redo surgery group. Eleven patients (22%) in the emergency surgery group had an ileostomy compared to 10 (11.5%) in the elective surgery group (p < 0.0001). In the emergency surgery group the median length of the resected small bowel was 10 cm longer than into the group having elective surgery for primary Crohn's disease.

CONCLUSIONS

Patients undergoing emergency surgery for Crohn's disease have a higher rate of stoma formation and 30-day complications. Laparoscopic surgery in the emergency setting has a higher conversion rate and involves resection of longer segments of small bowel.

Systematic review with meta-analysis: the prevalence of small intestinal bacterial overgrowth in inflammatory bowel disease

BACKGROUND

Current data on small intestinal bacterial overgrowth (SIBO) in patients with inflammatory bowel diseases (IBD) are controversial.

AIM

To conduct a systematic review and meta-analysis to determine the prevalence of SIBO in patients with ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

Electronic databases were searched up to May 2018 for studies reporting prevalence of SIBO in IBD patients. The prevalence rate of SIBO among IBD patients and the odds ratio (OR) and 95% CI of SIBO in IBD patients compared with controls were calculated.

RESULTS

The final dataset included 11 studies (1175 adult patients with IBD and 407 controls), all utilising breath test for diagnosis of SIBO. The proportion of SIBO in IBD patients was 22.3% (95% CI 19.92-24.68). The OR for SIBO in IBD patients was 9.51 (95% CI 3.39-26.68) compared to non-IBD controls, and high in both CD (OR = 10.86; 95% CI 2.76-42.69) and UC (OR = 7.96; 95% CI 1.66-38.35). In patients with CD, subgroup analysis showed the presence of fibrostenosing disease (OR = 7.47; 95% CI 2.51-22.20) and prior bowel surgery (OR = 2.38; 95% CI 1.65-3.44), especially resection of the ileocecal valve, increased the odds of SIBO. Individual studies suggest that combined small and large bowel disease but not disease activity may be associated with SIBO.

CONCLUSIONS

Overall, there is a substantial increase in the prevalence of SIBO in IBD patients compared to controls. Prior surgery and the presence of fibrostenosing disease are risk factors for SIBO in IBD.

Current perspectives on the diagnosis and management of functional anorectal disorders in patients with inflammatory bowel disease

Despite advances in inflammatory bowel disease (IBD) therapies, a significant proportion of patients with quiescent disease experience persistent, debilitating symptoms of faecal incontinence (FI), urgency and defaecatory disorders due to anorectal dysfunction. Such symptoms are often underreported or misdiagnosed and can lead to potentially premature treatment 'escalation' and under-utilisation of pelvic floor investigations. In this review article, we consider putative pathophysiological post-inflammatory changes resulting in altered anorectal sensitivity, motility and neuromuscular coordination and how this may drive symptoms in quiescent IBD. Finally, we discuss a pragmatic approach to investigating and managing anorectal dysfunction and highlight areas for future research for this often-neglected group of patients.

Small intestinal bacterial overgrowth is common after gastrectomy but with little impact on nutritional status

BACKGROUND

Available evidence assessing the impact of small intestinal bacterial overgrowth (SIBO) following gastrectomy is limited.

OBJECTIVES

To evaluate the prevalence of SIBO after gastrectomy and its association with malnutrition. To describe the antibiotic treatment required to correct it and if nutritional status improves.

MATERIAL AND METHODS

A prospective cohort study was performed at the Agencia Sanitaria Costa del Sol (Costa del Sol Health Agency) from 2012 to 2015. A hydrogen-methane breath test with oral glucose overload was performed. Demographic variables and nutritional parameters were collected at baseline and one month after effective treatment of SIBO. The antibiotic regimens and the number of treatment lines used were assessed.

RESULTS

Sixty gastrectomy patients were analysed, 58.3% of which were male. A sub-analysis of the curve was performed at 45min to minimise possible false positives, and SIBO was identified in 61.6% of cases. SIBO patients tended to have a lower BMI, although this trend was not statistically significant. After treatment with rifaximin, 94.6% of patients were still positive for SIBO, which fell to 85.7% after metronidazole. The rate of total antibiotic treatment failure was 67.6%. No statistically significant changes were found in nutritional parameters after treatment.

CONCLUSIONS

SIBO was identified in 61.6% of patients after gastrectomy. No correlation was found with any malnutrition parameter. Rifaximin and metronidazole were found to be largely ineffective in eradicating SIBO. When treatment was effective, the impact on malnutrition was negligible and may have been associated with other factors.

Testing and Treating Small Intestinal Bacterial Overgrowth Reduces Symptoms in Patients with Inflammatory Bowel Disease

BACKGROUND

Common mechanisms against small intestinal bacterial overgrowth (SIBO), including an intact ileocecal valve, gastric acid secretion, intestinal motility, and an intact immune system, are compromised in inflammatory bowel disease (IBD), and therefore, a relatively high incidence of SIBO has been reported in this population.

AIMS

We aimed to determine whether an improvement in IBD clinical activity scores is seen after testing and treating SIBO.

METHODS

A retrospective cohort study of 147 patients with inflammatory bowel disease who were referred for SIBO breath testing from 1/2012 to 5/2016 was performed. Characteristics of SIBO positive and treated patients were compared to SIBO negative patients, including the changes in Partial Mayo Score or Harvey Bradshaw Index (HBI), using Student's t test for continuous variables and Chi-squared or Fisher's exact test for categorical variables.

RESULTS

61.9% were SIBO positive and treated, and 38.1% were SIBO negative. In Crohn's disease, the median HBI decreased from 5 to 3 and 5 to 4, in the SIBO positive and negative groups, respectively (p = 0.005). In ulcerative colitis, the Partial Mayo Score decreased from 2 to 1.5 and 2 to 1, respectively (p = 0.607).

CONCLUSIONS

This study examines the clinical effect of testing and treating for SIBO in an IBD population. We see a significant reduction in HBI after testing for and treating SIBO. Future prospective studies are necessary to further investigate the role of SIBO in the evaluation and management of IBD.

Association of clinical and inflammatory markers with small bowel capsule endoscopy findings in Crohn's disease

BACKGROUND

Mucosal healing is an established treatment endpoint in Crohn's disease (CD). Still, clinical indices and inflammatory markers are used widely in CD surveillance.

AIM

The aim of this study was to investigate the diagnostic performance as well as the relationship of C-reactive protein (CRP) and Crohn's Disease Activity Index (CDAI) with small bowel capsule endoscopy's (SBCE) inflammation scoring index, the Lewis Score (LS).

PATIENTS AND METHODS

CDAI, CRP, and SBCE findings of 30 CD patients with isolated small bowel disease were retrieved from our academic institution patient records and were analyzed statistically.

RESULTS

SBCE showed significant mucosal inflammation [mean (SD) LS: 1599 (1380)], in nine (60.0%) of 15 patients who were in both clinical and biochemical remission. CDAI and CRP showed a weak and moderate correlation with LS (r=0.317, P=0.088 and r=0.516, P=0.004, respectively). The diagnostic performance of CDAI and CRP in predicting mucosal inflammation was as follows: sensitivity 23.8 and 52.4%; specificity 100 and 66.7%; positive predictive value 100 and 78.6%; and negative predictive value 36.0 and 37.5%. The area under the curve toward endoscopic activity prediction was 0.70 and 0.69, respectively.

CONCLUSION

Both CDAI and CRP underestimated endoscopic activity as expressed by the LS in a significant proportion of patients with quiescent disease.

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

GOALS

We studied the prevalence and predictors of small-intestinal bacterial overgrowth (SIBO) in Crohn's disease (CD) outpatients and the relationship between SIBO and intestinal and/or systemic inflammation.

BACKGROUND

The relationship of SIBO with systemic and intestinal inflammation in CD patients is unclear.

STUDY

In this cross-sectional study, conducted between June, 2013 and January, 2015, 92 CD patients and 97 controls with nonchronic gastrointestinal complaints were assessed for the presence of SIBO using the H2/CH4 glucose breath test. Multivariate logistic regression was performed to investigate the potential association between SIBO and demographic, disease-related data, systemic markers of inflammation (C-reactive protein, and erythrocyte sedimentation rate), and biomarker of intestinal inflammation [fecal calprotectin concentration (FCC)].

RESULTS

The SIBO rate was significantly higher in CD patients than in controls (32.6% vs. 12.4%, respectively, P=0.0008). Patients with and without SIBO were comparable with regard to demographics, systemic inflammatory biomarkers, and disease characteristics, except for the stricturing phenotype being more common in SIBO-positive CD patients (43.3% vs. 19.3%, P=0.015). Notably, FCC was significantly higher in SIBO-positive patients (median of 485.8 vs.132.7 μg/g; P=0.004). Patients presenting increased FCC and stricturing disease had an odds of 9.43 (95% confidence interval, 3.04-11.31; P<0.0001) and 3.83 (95% confidence interval, 1.54-6.75; P=0.025) respectively, for SIBO diagnosis.

CONCLUSIONS

In CD patients, SIBO is a highly prevalent condition. Stricturing phenotype and increased FCC were strongly and independently associated with the presence of SIBO. SIBO diagnostic work-up followed by directed treatment is recommended in CD patients who present stricturing disease, especially in those with concurrent intestinal inflammation.

Understanding the Gut Microbiota in Inflammatory and Functional Gastrointestinal Diseases

OBJECTIVE

During the last decade, experimental and observational studies have shown that patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) may have an altered intestinal microbial composition compared with healthy individuals. However, no uniform microbial signature has as yet been detected for either IBD or IBS. This review summarizes the current knowledge of microbial dysbiosis and its potential relationship to the pathophysiology in IBD and IBS.

METHODS

A selective review was conducted to summarize the current knowledge of gut microbiota in the pathophysiology of IBD and IBS.

RESULTS

Experimental and observational studies provide good evidence for intestinal microbial dysbiosis in subgroups of IBD and IBS. Still, no uniform disease pattern has been detected. This is most likely due to the heterogeneous nature of IBD and IBS, in combination with the effects of intrinsic and extrinsic factors. Such intrinsic factors include genetics, the gastrointestinal environment, and the host immune system, whereas extrinsic factors include early life diet, breastfeeding, and method of infant delivery.

CONCLUSIONS

Recent and ongoing work to define microbial dysbiosis in IBD and IBS shows promise, but future well-designed studies with well-characterized study individuals are needed. It is likely that the microbial dysbiosis in IBD and IBS is dependent on the natural disease course of IBD and symptom pattern in IBS. Therefore, assessment of the entire microbiota along the gastrointestinal tract, in relationship to confounding factors, symptom fluctuations, and other pathophysiological factors, is needed for further understanding of the etiology of these common diseases.

The prevalence of bacterial overgrowth syndrome and its associated factors in patients with inflammatory bowel diseases (according to the data of the Novosibirsk registry)

Aim. To assess the prevalence of bacterial overgrowth syndrome (BOS) and its risk factors in patients with inflammatory bowel diseases (IBD). Subjects and methods. The patients from the Novosibirsk IBD registry, who had undergone a hydrogen breath test (HBT) using a Gastro+ device, were examined. Results. In 93 IBD patients who had undergone a HBD, the prevalence of BOS was 48% (46.2% for ulcerative colitis and 51.2% for Crohn’s disease). There was a strong correlation between abdominal bloating, abdominal rumbling, and positive HBT results in both patient groups. During the HBT, the patients with BOS frequently complained of diarrhea, borborygmi, belching, and anxiety. Conclusion. The findings suggest that BOS is highly prevalent among patients with IBD. BOS is associated with clinical symptoms, such as abdominal bloating, abdominal rumbling, tearfulness, and irritability.

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

AIM

To identify a set of contributors, and weight and rank them on a pathophysiological basis.

METHODS

Patients who have undergone a lactulose or glucose hydrogen breath test to rule out small intestinal bacterial overgrowth (SIBO) for various clinical symptoms, including diarrhoea, weight loss, abdominal pain, cramping or bloating, were seen as eligible for inclusion in a retrospective single-centre study. Clinical data such as co-morbidities, medication, laboratory parameters and other possible risk factors have been identified from the electronic data system. Cases lacking or with substantially incomplete clinical data were excluded from the analysis. Suspected contributors were summarised under four different pathophysiological pathways (impaired gastric acid barrier, impaired intestinal clearance, immunosuppression and miscellaneous factors including thyroid gland variables) and investigated using the χ² test, Student’s t-test and logistic regression models.

RESULTS

A total of 1809 patients who had undergone hydrogen breath testing were analysed. Impairment of the gastric acid barrier (gastrectomy, odds ratio: OR = 3.5, PPI therapy OR = 1.4), impairment of intestinal clearance (any resecting gastric surgery OR = 2.6, any colonic resection OR = 1.9, stenosis OR = 3.4, gastroparesis OR = 3.4, neuropathy 2.2), immunological factors (any drug-induced immunosuppression OR = 1.8), altered thyroid gland metabolism (hypothyroidism OR = 2.6, levothyroxine therapy OR = 3.0) and diabetes mellitus (OR = 1.9) were associated significantly to SIBO. Any abdominal surgery, ileocecal resection, vagotomy or IgA-deficiency did not have any influence, and a history of appendectomy decreased the risk of SIBO. Multivariate analysis revealed gastric surgery, stenoses, medical immunosuppression and levothyroxine to be the strongest predictors. Levothyroxine therapy was the strongest contributor in a simplified model (OR = 3.0).

CONCLUSION

The most important contributors for the development of SIBO in ascending order are immunosuppression, impairment of intestinal clearance and levothyroxine use, but they do not sufficiently explain its emergence.

Diagnosis and treatment of small intestinal bacterial overgrowth

A huge number of bacteria are hosted in the gastrointestinal tract, following a gradient increasing towards the colon. Gastric acid secretion and intestinal clearance provide the qualitative and quantitative partitioning of intestinal bacteria; small intestinal bacteria overgrowth (SIBO) occurs when these barrier mechanisms fail. Diagnosis of SIBO is challenging due to the low specificity of symptoms, the frequent association with other diseases of the gastrointestinal tract and the absence of optimal objective diagnostic tests. The therapeutic approach to SIBO is oriented towards resolving predisposing conditions, and is supported by antibiotic treatment to restore the normal small intestinal microflora and by modifications of dietary habits for symptomatic relief. In the near future, metagenomics and metabolomics will help to overcome the uncertainties of SIBO diagnosis and the pitfalls of therapeutic management, allowing the design of a personalized strategy based on the direct insight into the small intestinal microbial community.

Motility Evaluation in the Patient with Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) suffer frequently from functional bowel diseases (FBD) and motility disorders. Management of FBD and motility disorders in IBD combined with continued treatment of a patient's IBD symptoms will likely lead to better clinical outcomes and improve the patient's quality of life. The goals of this review were to summarize the most recent literature on motility disturbances in patients with IBD and to give a brief overview of the ranges of motility disturbances, from reflux disease to anorectal disorders, and discuss their diagnosis and specific management.

Cumulative Length of Bowel Resection in a Population-Based Cohort of Patients With Crohn's Disease

BACKGROUND & AIMS

Little is known about the cumulative extent of bowel resection among patients with Crohn's disease.

METHODS

Using the resources of the Rochester Epidemiology Project, we identified a cohort of 310 incident cases of Crohn's disease from Olmsted County, Minnesota who were diagnosed between 1970 and 2004. Operative and pathology reports were reviewed for bowel resection length. Median bowel resection lengths (with interquartile range [IQR]) were calculated per resection, cumulatively, and as a rate per year of follow-up.

RESULTS

One hundred forty-seven patients underwent 1 or more bowel resections. The median follow-up time per patient was 13.6 years (range, 0.2-39 years). Among the 141 patients with resection data available, 211 resections were performed (100 patients with 1 resection, 24 with 2 resections, 9 with 3 resections, 6 with 4 resections, 1 with 5 resections, and 1 patient with 7 resections). The median length of bowel resected was 40 cm (IQR, 22-65 cm) at any resection. The median cumulative length of bowel resected was 64 cm (38-93 cm) during the follow-up period. The median (IQR) rate of bowel resected was 4.2 cm total bowel annually (2.8-7.7 cm). The median length resected was highest for the first resection (52 cm; IQR, 32-71 cm). A mixed regression analysis showed that the length of the first resection was significantly greater than that of the second (P = .002), without significant differences between the second and third or subsequent resections.

CONCLUSIONS

In a population-based cohort of patients with Crohn's disease, the median cumulative length of total bowel resected was 64 cm during the follow-up period; the median rate of bowel loss due to resection was 4.2 cm annually.

Glucose breath test and Crohn's disease: Diagnosis of small intestinal bacterial overgrowth and evaluation of therapeutic response

OBJECTIVE

Small intestinal bacterial overgrowth (SIBO) is characterized by an abnormal proliferation of bacterial species in the small bowel. It has been shown that patients with Crohn's disease (CD) have a higher risk of SIBO development. The aim of the present study was to investigate SIBO prevalence in CD patients, possible clinical predictors of SIBO development and response to antibiotic therapy.

MATERIAL AND METHODS

Sixty-eight patients (42 male, 26 female; mean age 49.3 ± 12.8 years) with CD reporting abdominal complaints were prospectively evaluated for SIBO with H2/CH4 glucose breath test (GBT).

RESULTS

Of the 68 patients enrolled, 18 (26.5%) tested positive for SIBO. Patients with SIBO exhibited increased stool frequency and significant reduction of stool solidity (p = 0.014), were older than patients tested negative to GBT (54.3 ± 13.0 years vs. 47.5 ± 12.3 years, p = 0.049), reported a longer history of CD (21.2 ± 10.3 years vs. 15.7 ± 10.2 years, p = 0.031) and showed a significant higher frequency of prior surgery (p = 0.001), revealing an association of number of surgical procedures (OR = 2.8315, 95% CI = 1.1525-6.9569, p = 0.023) with SIBO. Breath test normalization occurred in 13/15 patients evaluated after antibiotic and probiotic therapy. Although vitamin B12 levels were lower in patients with SIBO (p = 0.045) and a significant improvement was found after treatment (p = 0.011), this could be due to the heterogeneity, regarding vitamin B12 treatment, in our cohort.

CONCLUSION

SIBO is a frequent but underestimated condition in CD, which often mimics acute flare, effectively identified with GBT and could be treated with a combined antibiotic and probiotic therapy.

How to Diagnose and Treat IBD Mimics in the Refractory IBD Patient Who Does Not Have IBD

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract and includes both Crohn's disease and ulcerative colitis. Patients with IBD often present with abdominal pain, diarrhea, and rectal bleeding but may also have a wide variety of other symptoms such as weight loss, fever, nausea, vomiting, and possibly obstruction. Given that the presentation of IBD is not specific, the differential diagnosis is broad and encompasses a wide spectrum of diseases, many of which can mimic and/or even coexist with IBD. It is important for physicians to differentiate symptoms due to refractory IBD from symptoms due to IBD mimics when a patient is not responding to standard IBD treatment. Many of the various IBD mimics include infectious etiologies (viral, bacterial, mycobacterial, fungal, protozoal, and helminthic infections), vascular causes, other immune causes including autoimmune etiologies, drug-induced processes, radiation-induced, and other etiologies such as small intestinal bacterial overgrowth, diverticulitis, and bile acid malabsorption. Thoughtful consideration and evaluation of these potential etiologies through patient history and physical examination, as well as appropriate tests, endoscopic evaluation, and cross-sectional imaging is required to evaluate any patient presenting with symptoms consistent with IBD.

Small Intestinal Bacterial Overgrowth Syndrome Prevalence in Romanian Patients with Inflammatory Bowel Disease

BACKGROUND

small intestinal bacterial overgrowth (SIBO) is an entity commonly associated with digestive disease. Recently, its association with inflammatory bowel diseases (IBD) made the object of an increasing number of investigations. Sometimes symptoms of excessive bacterial populations may overlap or mimic flares of inflammatory disease.

METHOD

patients with IBD (CD - Crohn disease and UC - ulcerative colitis) in remission underwent screening for the presence of SIBO using the hydrogen breath test.

RESULTS

of the 75 patients tested, the breath test was positive for SIBO in 25.3% (30.77% of patients with CD and 19.4% of patients with UC). The risk factors associated with the presence of this syndrome were identified as: pancolonic impairment in UC, perianal and ileo-colonic involvement in CD, postoperative absence of the ileocecal valve. Patients in remission with bacterial overgrowth tend to present more frequently: a higher daily average of stools, a lower BMI (body mass index) and much more frequent complaints of persistent flatulence.

CONCLUSIONS

patients with Crohn's disease suffer from small intestinal bacterial overgrowth syndrome more frequently than those with ulcerative colitis. The hydrogen breath test may be used, along with other laboratory methods, to distinguish between an inflammatory bowel disease and an overlap of small intestinal bacterial overgrowth.

Postoperative Inflammatory Response in Crohn's Patients: A Comparative Study

BACKGROUND AND AIMS

Surgery for Crohn's disease [CD] can be complicated by an enhanced inflammatory response. This retrospective study aims to compare the inflammatory response measured by C-reactive protein [CRP] in patients operated for CD with patients undergoing similar surgery for colorectal cancer [CRC].

METHODS

All CD patients undergoing an ileocaecal resection between February 2001 and December 2013 were retrieved from a prospectively maintained database. The same number of patients with a CRC of the ascending colon, undergoing a laparoscopic right hemicolectomy between March 2009 and June 2014, were retrieved from a CRC database. CRP level during the first 7 postoperative days was used as primary outcome.

RESULTS

Totals of 112 consecutive CD patients (male 40.2%; median age: 32.3 yrs; interquartile range [IQR]: 25.2-45.1) and 112 consecutive CRC patients [male 53.6%; median age 71.6 yrs; IQR: 64.7-77.5] were included. Postoperative CRP level in the CD group was on average 27% higher compared with the CRC group [p = 0.02]. The day-specific differences in CRP values were 21% (p = 0.021, 95% confidence interval [CI]: 3% 41%), 41% [p = 0.005, 95% CI: 11%-79%], 49% [p = 0.007, 95% CI: 11%-96%], and 49% [p = 0.006, 95% CI: 12%-100%] higher for CD patients at Days 1, 4, 5, and 6 respectively. The difference in postoperative CRP level was partially due to differences in preoperative CRP level.

CONCLUSION

CD patients develop a higher postoperative CRP level, probably reflecting an enhanced postoperative inflammatory response, which may be triggered by a higher preoperative inflammatory state.

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.

Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth: A retrospective study of 932 patients

AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth (SIBO) using the D-Xylose breath test (XBT).

METHODS: We performed a retrospective cross-sectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronic medical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance (ANOVA) was used to test for several associations including age, gender, and body mass index (BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the -XBT group. P values of less than 0.05 (two-sided) were considered statistically significant.

RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT (P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test (P = 0.024). The mean BMI of positive XBT subjects was normal (24.5) and significantly lower than the subjects with a negative XBT (29.5) (P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease (GERD) (OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease (PUD) (OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis (GP) (OR = 2.04; 95%CI: 1.21-3.41, P < 0.01) and steroid use (OR = 1.35; 95%CI: 1.02-1.80, P = 0.01). Irritable bowel syndrome, independent proton-pump inhibitor (PPI) usage, or previous abdominal surgery was not significantly associated with a positive XBT. No single subdivision by gender or PPI use was associated with a significant difference in the odds ratios between any of the subsets.

CONCLUSION: Female gender, lower BMI, steroid use, PUD, GERD (independent of PPI use), and GP were more prevalent in patients with SIBO, determined by a positive XBT. Increasing age was associated with SIBO in females, but not in males.

Small intestinal bacterial overgrowth syndrome in children

Introduction

Small intestinal bacterial overgrowth syndrome (SIBO) is defined as an increased number of nonpathogenic bacteria over 10⁵ organisms in 1 millilitre of small intestine content. The most common predisposing factors include, among others, gut motility disorders and chronic use of proton pump inhibitors. The results of recent studies indicate the importance of SIBO in gastrointestinal diseases.

Aim

To assess the prevalence of SIBO in children with abdominal pain.

Material and methods

One hundred children (59 girls and 41 boys) aged from 4 to 17 years (mean age: 10.47 ±3.73 years), hospitalised due to abdominal pain, were enrolled in the study. Hydrogen breath test (HBT) with lactulose was established among all patients. Expired air was analysed using a Gastrolyzer (Bedfont).

Results

The HBT result was positive in 63 (63%) children with abdominal pain; including 40 girls (67.8%) and 23 boys (56.1%). The test was positive in the group of 29 (46%) children aged under 10 years and in the group of 34 (54%) children aged over 10 years. Among the patients who reported for the control study 88% achieved a normalisation of HBT after treatment.

Conclusions

The prevalence of positive HBT results in the group of patients with abdominal pain is over 60%. Small intestinal bacterial overgrowth syndrome should be considered as one of the causes of abdominal pain in children. The SIBO in children shows a good response to treatment.

Intestinal Microbiome, Small Intestinal Bacterial Overgrowth and Inflammatory Bowel Diseases - What are the Connections?

IBD (inflammatory bowel diseases) represent chronic idiopathic inflammatory diseases, prone to relapse in the digestive tract; it is estimated that they result from the interaction of the intestinal microbiome with the intestinal immune system. The inflammatory microbiome exerts multiple beneficial roles. Perhaps the central element to developing IBD is dysbiosis; there is still an incompletely established association between intestinal microbiome changes in patients with IBD and SIBO (small intestinal bacterial overgrowth). Influencing the intestinal microbiome may play an adjuvant therapeutic role in the treatment of IBD. We present a synthesis of the connections between the entities mentioned above.

Pain management in patients with inflammatory bowel disease: translational approaches from bench to bedside

Abdominal pain is a common symptom in patients with inflammatory bowel disease (IBD) that negatively affects quality of life and can lead to increased health-seeking behavior. Although abdominal pain has been traditionally attributed to inflammation, there is growing literature demonstrating the existence of functional abdominal pain in patients with IBD, of which there are a variety of potential causes. Thus, when approaching a patient with IBD who has abdominal pain, in addition to IBD-related complications (e.g., inflammation/stricture), it is important to screen for related contributors, including peripheral factors (visceral hypersensitivity, bacterial overgrowth, and bowel dysmotility) and centrally mediated neurobiological and psychosocial underpinnings. These central factors include psychological symptoms/diagnoses, sleep disturbance, and stress. Opioid-induced hyperalgesia (e.g., narcotic bowel syndrome) is also growing in recognition as a potential central source of abdominal pain. This review draws from clinical studies and animal models of colitis and abdominal pain to consider how knowledge of these potential etiologies can be used to individualize treatment of abdominal pain in patients with IBD, including consideration of potential novel treatment modalities for the future. Accurate assessment of the source(s) of pain in patients with IBD can help guide appropriate diagnostic workup and use of disease-modifying therapy.

Small intestinal bacterial overgrowth in inactive Crohn’s disease: Influence of thiopurine and biological treatment

AIM: To investigate the influence of thiopurines and biological drugs on the presence of small intestinal bacterial overgrowth (SIBO) in patients with inactive Crohn’s disease (CD).

METHODS: This was a prospective study in patients with CD in remission and without corticosteroid treatment, included consecutively from 2004 to 2010. SIBO was investigated using the hydrogen glucose breath test.

RESULTS: One hundred and seven patients with CD in remission were included. Almost 58% of patients used maintenance immunosuppressant therapy and 19.6% used biological therapy. The prevalence of SIBO was 16.8%. No association was observed between SIBO and the use of thiopurine Immunosuppressant (12/62 patients), administration of biological drugs (2/21 patients), or with double treatment with an anti-tumor necrosis factor drugs plus thiopurine (1/13 patients). Half of the patients had symptoms that were suggestive of SIBO, though meteorism was the only symptom that was significantly associated with the presence of SIBO on univariate analysis (P < 0.05). Multivariate analysis revealed that the presence of meteorism and a fistulizing pattern were associated with the presence of SIBO (P < 0.05).

CONCLUSION: Immunosuppressants and/or biological drugs do not induce SIBO in inactive CD. Fistulizing disease pattern and meteorism are associated with SIBO.

Review article: small intestinal bacterial overgrowth--prevalence, clinical features, current and developing diagnostic tests, and treatment

BACKGROUND

The symptoms and signs of small intestinal bacterial overgrowth (SIBO) are often identical to a variety of diseases and can lead to diagnostic confusion.

AIMS

To review the diagnostic options for SIBO and present new investigative options for the condition.

METHODS

A literature search was performed on MEDLINE, EMBASE and Web of Science for English articles and abstracts. Search terms included free text words and combinations of the following terms 'small intestinal bacterial overgrowth', 'small bowel bacterial overgrowth', 'diagnostic tests', 'treatment', 'antibiotics', 'probiotics', 'metabonomics', 'proton nuclear magnetic resonance spectroscopy', 'electronic nose' and 'field asymmetric ion mobility spectrometry'.

RESULTS

All of the available methods to test for SIBO have inherent limitations and no 'gold-standard' diagnostic test for the condition exists. Accurate diagnosis of SIBO requires identification of bacterial species growing inappropriately within the small intestine and symptom response to antibiotics. Proton nuclear magnetic resonance spectroscopy, electronic nose technology and/or field asymmetric ion mobility spectrometry may represent better investigative options for the condition.

CONCLUSIONS

Novel diagnostic options are needed to supplement or replace available tests.

Impact of ileocecal resection and concomitant antibiotics on the microbiome of the murine jejunum and colon. PLoS One. 2013;8:e73140. [PMID: 24015295 PMCID: PMC3754918 DOI: 10.1371/journal.pone.0073140]

Ileocecal resection (ICR) is a commonly required surgical intervention in unmanageable Crohn's disease and necrotizing enterocolitis. However, the impact of ICR, and the concomitant doses of antibiotic routinely given with ICR, on the intestinal commensal microbiota has not been determined. In this study, wild-type C57BL6 mice were subjected to ICR and concomitant single intraperitoneal antibiotic injection. Intestinal lumen contents were collected from jejunum and colon at 7, 14, and 28 days after resection and compared to non-ICR controls. Samples were analyzed by 16S rRNA gene pyrosequencing and quantitative PCR. The intestinal microbiota was altered by 7 days after ICR and accompanying antibiotic treatment, with decreased diversity in the colon. Phylogenetic diversity (PD) decreased from 11.8 ± 1.8 in non-ICR controls to 5.9 ± 0.5 in 7-day post-ICR samples. There were also minor effects in the jejunum where PD values decreased from 8.3 ± 0.4 to 7.5 ± 1.4. PCoA analysis indicated that bacterial populations 28 days post-ICR differed significantly from non-ICR controls. Moreover, colon and jejunum bacterial populations were remarkably similar 28 days after resection, whereas the initial communities differed markedly. Firmicutes and Bacteroidetes were the predominant phyla in jejunum and colon before ICR; however, Firmicutes became the vastly predominant phylum in jejunum and colon 28 days after ICR. Although the microbiota returned towards a homeostatic state, with re-establishment of Firmicutes as the predominant phylum, we did not detect Bacteroidetes in the colon 28 days after ICR. In the jejunum Bacteroidetes was detected at a 0.01% abundance after this time period. The changes in jejunal and colonic microbiota induced by ICR and concomitant antibiotic injection may therefore be considered as potential regulators of post-surgical adaptive growth or function, and in a setting of active IBD, potential contributors to post-surgical pathophysiology of disease recurrence.

Diagnosis and management of small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) can result from failure of the gastric acid barrier, failure of small intestinal motility, anatomic alterations, or impairment of systemic and local immunity. The current accepted criteria for the diagnosis of SIBO is the presence of coliform bacteria isolated from the proximal jejunum with >10(5) colony-forming units/mL. A major concern with luminal aspiration is that it is only one random sampling of the small intestine and may not always be representative of the underlying microbiota. A new approach to examine the underlying microbiota uses rapid molecular sequencing, but its clinical utilization is still under active investigation. Clinical manifestations of SIBO are variable and include bloating, flatulence, abdominal distention, abdominal pain, and diarrhea. Severe cases may present with nutrition deficiencies due to malabsorption of micro- and macronutrients. The current management strategies for SIBO center on identifying and correcting underlying causes, addressing nutrition deficiencies, and judicious utilization of antibiotics to treat symptomatic SIBO.

Diets rich in n-6 PUFA induce intestinal microbial dysbiosis in aged mice

Controversies have emerged regarding the beneficial v. detrimental effects of dietary n-6 PUFA. The alteration of the intestinal microbiota, a phenomenon termed dysbiosis, occurs during several chronic inflammatory diseases, but has not been well studied in an aged population. With present ‘Western’ diets predominantly composed of n-6 PUFA, we hypothesised that PUFA-rich diets cause intestinal dysbiosis in an aged population. C57BL/6 mice (aged 2 years) were fed a high-fat (40% energy), isoenergetic and isonitrogenous diet composed of rapeseed oil, maize oil or maize oil supplemented with fish oil. We examined ileal microbiota using fluorescence in situ hybridisation and stained tissues by immunofluorescence for the presence of immune cells and oxidative stress. We observed that feeding high-fat diets rich in n-6 PUFA promoted bacterial overgrowth but depleted microbes from the Bacteroidetes and Firmicutes phyla. This corresponded with increased body mass and infiltration of macrophages and neutrophils. Fish oil supplementation (rich in long-chain n-3 PUFA like DHA and EPA) restored the microbiota and inflammatory cell infiltration and promoted regulatory T-cell recruitment. However, fish oil supplementation was associated with increased oxidative stress, evident by the increased presence of 4-hydroxynonenal, a product of lipid peroxidation. These results suggest that an n-6 PUFA-rich diet can cause dysbiosis and intestinal inflammation in aged mice. However, while fish oil supplementation on an n-6 PUFA diet reverses dysbiosis, the combination of n-6 and n-3 PUFA, like DHA/EPA, leads to increased oxidative stress, which could exacerbate gastrointestinal disorders in the elderly.

[Proton-pump inhibitor therapy and small bowel bacterial contamination]

There are several causes of small bowel contamination. The effects of the long-term proton pump inhibitor treatment on the development of bowel symptoms and/or small intestinal bacterial overgrowth have been highlighted only in the past decade. The main diagnostic method is the hydrogen breath test that gives quantitative results with a simple, non-invasive procedure. There is a limited number of publications in the literature about the effects of proton pump inhibitor drugs on bowel bacterial milieau. Our results based on the investigations of two medical centres in Budapest show consistency with international data: the positive hydrogen breath test was present in 21% of the population using long-term proton pump inhibitors. In uncomplicated cases, symptom-free condition could be reached with probiotics, whereas in long lasting, chronic small intestinal bacterial overgrowth, antibiotic treatment should be considered. Rifaximin, a non-absorbable antibiotic showed high efficacy in the treatment of small intestinal bacterial overgrowth, with fewer side effects compared to systemic antibiotics.

Diarrhea in chronic inflammatory bowel diseases

Diarrhea is a common clinical feature of inflammatory bowel diseases and may be accompanied by abdominal pain, urgency, and fecal incontinence. The pathophysiology of diarrhea in these diseases is complex, but defective absorption of salt and water by the inflamed bowel is the most important mechanism involved. In addition to inflammation secondary to the disease, diarrhea may arise from a variety of other conditions. It is important to differentiate the pathophysiologic mechanisms involved in the diarrhea in the individual patient to provide the appropriate therapy. This article reviews microscopic colitis, ulcerative colitis, and Crohn's disease, focusing on diarrhea.