Small-bowel aspiration during upper esophagogastroduodenoscopy: Rao technique

Gas-tly Interpretations: A Case-Based Approach to the Nuances of SIBO Breath Testing

PURPOSE OF REVIEW

Breath testing to diagnose intestinal microbial overgrowth (MO) is being increasingly utilized, in part due to direct-to-consumer testing modalities. However, the concept of breath testing in the diagnosis of MO is controversial due to numerous limitations regarding optimal substrate, diagnostic thresholds, and confounding variables. We provide seven real-world cases which comprehensively illustrate the principles and nuances of the interpretation of breath testing.

RECENT FINDINGS

We highlight recent studies which examine the optimal substrate for breath testing (glucose versus lactulose), the subtypes and clinical significance of breath test patterns including hydrogen, methane, and hydrogen-sulfide, elevated baseline gas levels, and confounders to breath test interpretation including transit time and diet. Reviewing the latest evidence, we provide recommendations for a personalized interpretation of breath tests utilizing unique patient factors. We conclude with an algorithm to assist clinicians in providing more accurate diagnoses.

Bidirectional endoscopic and pharmacological approach for the treatment of severe right-sided colonic stool impaction

A female patient in her 40s with scleroderma and Behçet's disease presented with dehydration, weight loss, fever and stool impaction. She failed aggressive laxatives and rectal enemas and was referred for colectomy. Abdominal X-ray revealed severe proximal colonic faecal impaction. We used a bidirectional approach to stimulate laxation composed of jejunal infusion of magnesium citrate using enteroscopy, gastrografin infusion into the right colon using colonoscopy, and intravenous neostigmine to stimulate peristalsis. This novel, three-pronged, outpatient approach using osmotic laxatives and peristaltic stimulants facilitated successful disimpaction over 36 hours, preventing possible colonic perforation or colectomy in a complex patient with right-sided stool impaction and comorbidities. This is a single case report that does not provide evidence for the safety or efficacy of a new treatment strategy.

DIAGNOSIS AND TREATMENT OF SMALL INTESTINAL BACTERIAL OVERGROWTH: AN OFFICIAL POSITION PAPER FROM THE BRAZILIAN FEDERATION OF GASTROENTEROLOGY

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is a condition characterized by an abnormal increase in bacterial population in the small intestine, leading to symptoms such as bloating, abdominal pain, distension, diarrhea, and eventually malabsorption. The diagnosis and management of SIBO remain challenging due to overlapping symptoms with other gastrointestinal disorders such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and coeliac disease.

OBJECTIVE

This article aims to review current evidence on the diagnosis and treatment of SIBO, with a focus on strategies suitable for the Brazilian healthcare system.

METHODS

A comprehensive literature review was performed, focusing on clinical guidelines, randomized controlled trials, and cohort studies concerning SIBO. Diagnostic methods, including breath tests and direct aspiration techniques, were critically analyzed. Treatment approaches, including antibiotics, dietary modifications, and probiotics, were reviewed. The recommendations were formulated based on a panel of gastroenterologists, members of the Brazilian Federation of Gastroenterology (FBG), with approval from the majority of the members.

RESULTS

Breath tests using glucose and lactulose remain the most commonly used non-invasive diagnostic tools, though they are subject to limitations such as false positives and false negatives. Treatment with rifaximin is effective in most cases of SIBO, while systemic antibiotics like metronidazole and ciprofloxacin are alternatives. Probiotics and dietary interventions, particularly low FODMAP diets, can complement antibiotic therapy. Long-term follow-up is essential due to the recurrence rate, which is common in SIBO patients.

CONCLUSION

Standardizing SIBO diagnosis and treatment in Brazil is essential to reduce diagnostic delays and optimize care, especially given the disparities and heterogeneity in clinical practice across the country. This article provides evidence-based recommendations to guide clinical practice. Further research is needed to refine diagnostic methods, explore novel treatment strategies, and better understand the specific characteristics of the Brazilian population.

Evaluation of a Novel Smart Capsule Bacterial Detection System Device for Diagnosis of Small Intestinal Bacterial Overgrowth

BACKGROUND

There is a large unmet need for alternative, non-invasive, and accurate diagnosis of small intestinal bacterial overgrowth (SIBO). The smart capsule bacterial detection system (SCBDS) device contains a targeted sampling technology and an onboard SCBDS assay to detect metabolically active bacteria in the small intestine. Here, we evaluated the agreement of SCBDS assay with duodenal aspiration/culture ex vivo in a multicenter clinical study.

METHODS

Duodenal aspiration was performed in subjects with gastrointestinal symptoms suggestive of SIBO. Aspirated fluid was sent to local and central microbiology labs to evaluate the agreement for detecting bacteria with SCBDS assay compared to the total bacterial count (TBC) reference standard. The performance of SCBDS assay was evaluated using a receiver operator curve, sensitivities, and specificities.

KEY RESULTS

Aspirates from 66 patients were collected and analyzed for TBC and SCDBS assay. The overall agreement between the two assays was 82%-92% across 3 clinical sites. The SCBDS assay had a sensitivity of 67%-100% and a specificity of 90%-97% using either ≥ 103 or 105 CFU mL-1 cutoff. Additionally, there was a good correlation (r = 0.82) for the TBC culture between the local and central labs.

CONCLUSIONS AND INFERENCES

The SCBDS assay showed a high level of agreement with TBC and improved performance compared to other non-invasive tests. These results demonstrate the potential utility of SCBDS device to aid SIBO diagnosis as a simple and non-invasive tool that merits further clinical validation.

Bakterielle Fehlbesiedlung des Dünndarms

SIBO (Small Intestinal Bacterial Overgrowth) ist durch eine bakterielle Überwucherung oder Fehlbesiedlung des Dünndarms in Kombination mit intestinalen Symptomen definiert. Intestinale Stase, Hypochlorhydrie, Immundefizienz, Alter u.a. sind auslösende Faktoren. Die Therapie beinhaltet die Behandlung der auslösenden Grunderkrankung, den Ausgleich einer Mangelernährung, den Einsatz von Antibiotika und Probiotika sowie diätetische Maßnahmen.

Understanding Our Tests: Hydrogen-Methane Breath Testing to Diagnose Small Intestinal Bacterial Overgrowth

There is increasing appreciation that small intestinal bacterial overgrowth (SIBO) drives many common gastrointestinal symptoms, including diarrhea, bloating, and abdominal pain. Breath testing via measurement of exhaled hydrogen and methane gases following ingestion of a readily metabolized carbohydrate has become an important noninvasive testing paradigm to help diagnose SIBO. However, because of a number of physiological and technical considerations, how and when to use breath testing in the diagnosis of SIBO remains a nuanced clinical decision. This narrative review provides a comprehensive overview of breath testing paradigms including the indications for testing, how to administer the test, and how patient factors influence breath testing results. We also explore the performance characteristics of breath testing (sensitivity, specificity, positive and negative predictive values, likelihood ratios, and diagnostic odds ratio). Additionally, we describe complementary and alternative tests for diagnosing SIBO. We discuss applications of breath testing for research. Current estimates of SIBO prevalence among commonly encountered high-risk populations are reviewed to provide pretest probability estimates under a variety of clinical situations. Finally, we discuss how to integrate breath test performance characteristics into clinical care decisions using clinical predictors and the Fagan nomogram.

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.

Bacterial overgrowth and lactose intolerance: how to best assess

PURPOSE OF REVIEW

To provide an up-to-date review on the clinical assessment of two important gastrointestinal problems with overlapping symptomatology but diverse cause and testing methods. Small intestinal bacterial overgrowth (SIBO) is characterized by the presence of excess bacteria in the small intestine associated with bloating, distention, gas, and diarrhea. Lactose intolerance is caused by lactase enzyme deficiency in the small bowel mucosa leading to lactose malabsorption and symptoms of bloating, gas, and diarrhea.

RECENT FINDINGS

SIBO is assessed by hydrogen/methane breath test using glucose as a substrate and/or small bowel aspirate and culture but these tests have shortcomings. Consequently, several new diagnostic techniques, including novel capsule technologies and other approaches are being evaluated. Lactose intolerance can be assessed by hydrogen/methane breath test using lactose as a substrate, or small bowel mucosal lactase assay, genetic testing and lactose tolerance test, although the efficacy and practicality of these diagnostic modalities are not equal.

SUMMARY

In clinical practice, gas, bloating, distention, pain, and diarrhea are common gastrointestinal symptoms that often remain unexplained when routine gastrointestinal endoscopy, imaging, and stool tests are negative. These patients should be evaluated for SIBO and/or food intolerances including lactose intolerance.