Small Intestinal Bacterial Overgrowth in Patients with Refractory Functional Gastrointestinal Disorders

Critical appraisal of the SIBO hypothesis and breath testing: A clinical practice update endorsed by the European society of neurogastroenterology and motility (ESNM) and the American neurogastroenterology and motility society (ANMS)

BACKGROUND

There is compelling evidence that microbe-host interactions in the intestinal tract underlie many human disorders, including disorders of gut-brain interactions (previously termed functional bowel disorders), such as irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) has been recognized for over a century in patients with predisposing conditions causing intestinal stasis, such as surgical alteration of the small bowel or chronic diseases, including scleroderma and is associated with diarrhea and signs of malabsorption. Over 20 years ago, it was hypothesized that increased numbers of small intestine bacteria might also account for symptoms in the absence of malabsorption in IBS and related disorders. This SIBO-IBS hypothesis stimulated significant research and helped focus the profession's attention on the importance of microbe-host interactions as a potential pathophysiological mechanism in IBS.

PURPOSE

However, after two decades, this hypothesis remains unproven. Moreover, it has led to serious unintended consequences, namely the widespread use of unreliable and unvalidated breath tests as a diagnostic test for SIBO and a resultant injudicious use of antibiotics. In this review, we examine why the SIBO hypothesis remains unproven and, given the unintended consequences, discuss why it is time to reject this hypothesis and its reliance on breath testing. We also examine recent IBS studies of bacterial communities in the GI tract, their composition and functions, and their interactions with the host. While these studies provide important insights to guide future research, they highlight the need for further mechanistic studies of microbe-host interactions in IBS patients before we can understand their possible role in diagnosis and treatment of patient with IBS and related disorders.

Altered resting-state brain activity in functional dyspepsia patients: a coordinate-based meta-analysis

Background

Neuroimaging studies have identified aberrant activity patterns in multiple brain regions in functional dyspepsia (FD) patients. However, due to the differences in study design, these previous findings are inconsistent, and the underlying neuropathological characteristics of FD remain unclear.

Methods

Eight databases were systematically searched for literature from inception to October 2022 with the keywords "Functional dyspepsia" and "Neuroimaging." Thereafter, the anisotropic effect size signed the differential mapping (AES-SDM) approach that was applied to meta-analyze the aberrant brain activity pattern of FD patients.

Results

A total of 11 articles with 260 FD patients and 202 healthy controls (HCs) were included. The AES-SDM meta-analysis demonstrated that FD patients manifested increased activity in the bilateral insula, left anterior cingulate gyrus, bilateral thalamus, right precentral gyrus, left supplementary motor area, right putamen, and left rectus gyrus and decreased functional activity in the right cerebellum compared to the HCs. Sensitivity analysis showed that all these above regions were highly reproducible, and no significant publication bias was detected.

Conclusion

The current study demonstrated that FD patients had significantly abnormal activity patterns in several brain regions involved in visceral sensation perception, pain modulation, and emotion regulation, which provided an integrated insight into the neuropathological characteristics of FD.

Research trends in the field of the gut-brain interaction: Functional dyspepsia in the spotlight – An integrated bibliometric and science mapping approach

Objectives

This study aims to perform a bibliometric analysis of functional dyspepsia (FD), which includes visualizing bibliographic information, in order to identify prevailing study themes, topics of interest, contributing journals, countries, institutions, and authors as well as co-citation patterns.

Methods

The Web of Science™ Core Collection Database was used to retrieve all peer-reviewed scientific publications related to FD research. The validated search terms were entered into the “title” and “author keywords” fields, and the results were sorted by publication year from 2006 to 2022. There were no restrictions on language. On 12 February 2023, a manual export of the complete metadata for each original publication and review article was performed. CiteSpace was used to reveal co-authorship, publication, and co-citation patterns to find prominent authors, organizations, countries, and journals in FD research as well as to identify author keywords with strong citation bursts, which could indicate an emerging research area. VOSviewer was used to build the co-occurrence indicator (co-word) to identify the main author keywords on which previous studies focused and to induce clustered scientific landscape for two consecutive periods to identify intriguing areas for future research.

Results

A search of the database retrieved 2,957 documents. There was a wave-like pattern in the number of publications until 2017, after which there was a spike in publication volume. The USA, China, and Japan provided the majority of contributions. In terms of institution, Mayo Clin, Univ Newcastle, and Katholieke Univ Leuven were found to be the prolific institutions. Additionally, the results indicate that eastern Asian researchers contributed significantly to the global knowledge of literature that led other countries; however, Canada, the USA, Australia, England, and Germany were found to have the highest degree of betweenness centrality. Nicholas J. Talley, Jan Tack, Gerald Holtmann, Michael Camilleri, Ken Haruma, and Paul Moayyedi occupied the top positions based on productivity and centrality indicators. Six thematic clusters emerged (Helicobacter pylori infection; pathophysiological mechanisms of FD; extraintestinal co-morbidities and overlap syndromes associated with FD; herbal medicine in FD; diabetic gastroparesis; and dietary factors in FD). “Acupuncture,” “duodenal eosinophilia,” “gut microbiota,” and others were among the author keywords with rising prevalence.

Conclusion

In FD research, eastern Asian countries have established themselves as major contributors with the highest publishing productivity; however, research has primarily been driven by North America, Europe, and Australia, where cooperation is generally more active and highly influential scientific results are produced. Our analysis suggests that increased investments, training of human resources, improved infrastructures, and expanded collaborations are essential to improving the quality of FD research in Asia. The emerging author keyword analysis suggests that eosinophil-mast cell axis, gut microbiota, mental disorders, and acupuncture are the key areas that attract researchers’ attention as future research boulevards. There is a highly skewed distribution of research output across Asia, with most focus on complementary and alternative medicine (CAM) coming from Chinese, Japanese, and South Korean centers. However, CAM remains an underexplored area of research in the context of FD, and it deserves greater research efforts in order to obtain quality scientific evidence. Furthermore, we propose that the research framework of CAM should not be limited to dysmotility; rather, it could be interpreted within a more holistic context that includes the brain-gut-microbiota axis, as well as novel concepts such as duodenitis, increased mucosal permeability, and infiltration and activation of eosinophils and mast cells, among others. Overall, we provided bibliometrics-based overviews of relevant literature to researchers from different backgrounds and healthcare professionals to provide an in-depth overview of major trends in FD research.

Disorders of Gut-Brain Interaction in a National Cohort of Children With Down Syndrome

Background/Aims

Disorders of brain-gut interaction (DGBIs) are present in adults and children around the world. Down syndrome (DS) is the most common chromosomal condition in humans. While DS has associations with many organic medical conditions, the frequency of DGBIs in children and adolescents with DS has not previously been studied. We assess the rate of DGBIs in children and adolescents 4-18 years of age with DS in the United States using the Rome IV criteria by caregiver report.

Methods

This is a cross-sectional national survey study in which caregivers (n = 114) of children with DS completed an online survey about their child's gastrointestinal symptoms and quality of life (QoL).

Results

Using the Rome IV parent-report diagnostic questionnaire, 51.8% of children met symptom-based criteria for at least 1 DGBI. Functional constipation (36.0%) and irritable bowel syndrome (14.9%) were the most common disorders identified. QoL was lower in children with at least 1 disorder as compared to children who did not meet criteria for any disorders (mean QoL = 62.3 vs mean QoL = 72.9, P < 0.001). Almost all children with DS and concomitant autism (87.5%) had at least 1 DGBI.

Conclusions

DGBIs are common in children with DS and are associated with diminished QoL.

Role of the duodenal microbiota in functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a common and debilitating gastrointestinal disorder attributed to altered gut-brain interactions. While the etiology of FD remains unknown, emerging research suggests the mechanisms are likely multifactorial and heterogenous among patient subgroups. Small bowel motor disturbances, visceral hypersensitivity, chronic microinflammation, and increased intestinal tract permeability have all been linked to the pathogenesis of FD. Recently, alterations to the gut microbiome have also been implicated to play an important role in the disease. Changes to the duodenal microbiota may either trigger or be a consequence of immune and neuronal disturbances observed in the disease, but the mechanisms of influence of small intestinal flora on gastrointestinal function and symptomatology are unknown.

PURPOSE

This review summarizes and synthesizes the literature on the link between the microbiota, low-grade inflammatory changes in the duodenum and FD. This review is not intended to provide a complete overview of FD or the small intestinal microbiota, but instead outline some of the key conceptual advances in understanding the interactions between altered gastrointestinal bacterial communities; dietary factors; host immune activation; and stimulation of the gut-brain axes in patients with FD versus controls. Current and emerging treatment approaches such as dietary interventions and antibiotic or probiotic use that have demonstrated symptom benefits for patients are reviewed, and their role in modulating the host-microbiota is discussed. Finally, suggested opportunities for diagnostic and therapeutic improvements for patients with this condition are presented.

Small Intestinal Bacterial Overgrowth In Various Functional Gastrointestinal Disorders: A Case-Control Study

INTRODUCTION

Small intestinal bacterial overgrowth (SIBO) is prevalent in irritable bowel syndrome (IBS), but its' association with other functional gastrointestinal disorders (FGIDs) is less certain. This study aimed to explore SIBO in a multi-racial Asian population with various FGIDs compared to non-FGID controls.

METHODOLOGY

Consecutive Asian adults with Rome III diagnosed common FGIDs (functional dyspepsia/FD, IBS and functional constipation/FC) and non-FGID controls were subjected to glucose breath testing, with hydrogen (H2) and methane (CH4) levels determined.

RESULTS

A total of 244 participants (FGIDs n = 186, controls n = 58, median age 45 years, males 36%, Malay ethnicity 76%) were recruited. FGIDs had a higher prevalence trend of SIBO compared to controls (16% FGIDs vs. 10% controls, p = 0.278) with 14% in FD, 18% in IBS and 17% in FC. Compared to controls, SIBO was associated with diarrhoea-predominant IBS (IBS-D) (24% vs. 10%, P = 0.050) but not with other types of FGIDs. IBS-D remained an independent predictor of SIBO (OR = 2.864, 95% CI 1.160-7.071, p = 0.023) but not PPI usage nor history of diabetes (both p > 0.050) at multivariate analysis. Compared to controls, SIBO in IBS-D was associated with an elevated H₂ level (≥ 20 ppm from baseline) (18% vs. 3%, p = 0.017), but not CH4 levels (≥ 10 ppm) (9% vs. 7%, p = 0.493). In addition, no difference was found in the prevalence of methane-positive SIBO between chronic constipation (constipation-predominant IBS and FC) compared to controls (9% vs. 7%, P = 0.466).

CONCLUSION

SIBO is prevalent amongst multi-ethnic Asian adults with and without FGIDs. Amongst various FGIDs, only IBS-D is significantly associated with SIBO.

Bi-Directionality of the Microbiota-Gut-Brain Axis in Patients With Functional Dyspepsia: Relevance of Psychotherapy and Probiotics

Functional dyspepsia is one of the most commonly diagnosed disorders of the gut-brain interaction worldwide. The precise pathogenesis of functional dyspepsia is complex and remains incompletely understood. Therefore, advances in the understanding of functional dyspepsia could change clinical practice. The aim of this review is to highlight the relevance of psychotherapy and probiotics in the context of the microbiota-gut-brain axis in the pathophysiology and especially in the treatment of functional dyspepsia. Therefore, studies which have been conducted to investigate the role of psychotherapy and probiotics in FD and the microbiota-gut-brain axis in the pathophysiology of functional dyspepsia were examined, and the outcomes of this research summarized. There might be a link between changes in the microbiome and functional dyspepsia. Even though, specific alterations in the microbiome that may be pathognomonic in functional dyspepsia remain unclear, the use of probiotics became a viable treatment option for patients with functional dyspepsia. Since mental illness also plays an important role in the pathophysiology of functional dyspepsia, psychotherapy is a useful treatment method, with additional study results indicating that psychotherapy may also shift the microbiome in a favorable direction. Moreover, other findings suggest that probiotics can be used not only to alleviate gastrointestinal symptoms in functional dyspepsia, but also to treat or even prevent mental disorders in these patients. In summary, in this review we highlight the bi-directionality of the microbiota-gut-brain axis in the pathophysiology of functional dyspepsia. Although there are multiple treatment approaches, the burden of disease in patients with functional dyspepsia is still enormous and a definitive therapy to cure this disease does not (yet) exist. Lastly, there is a lack of studies on the impact of dysbiosis, mental health and probiotics on pathophysiology and symptomatology in functional dyspepsia which should be investigated in future studies.

Asian-Pacific consensus on small intestinal bacterial overgrowth in gastrointestinal disorders: An initiative of the Indian Neurogastroenterology and Motility Association

In the clinical setting, small intestinal bacterial overgrowth (SIBO) is a frequent, but under-diagnosed entity. SIBO is linked to various gastrointestinal (GI) and non-GI disorders with potentially significant morbidity. The optimal management of SIBO is undefined while there is a lack of published consensus guidelines. Against this background, under the auspices of the Indian Neurogastroenterology and Motility Association (INMA), formerly known as the Indian Motility and Functional Diseases Association (IMFDA), experts from the Asian-Pacific region with extensive research and clinical experience in the field of gut dysbiosis including SIBO developed this evidence-based practice guideline for the management of SIBO utilizing a modified Delphi process based upon 37 consensus statements, involving an electronic voting process as well as face-to-face meetings and review of relevant supporting literature. These statements include 6 statements on definition and epidemiology; 11 on etiopathogenesis and pathophysiology; 5 on clinical manifestations, differential diagnosis, and predictors; and 15 on investigations and treatment. When the proportion of those who voted either to accept completely or with minor reservations was 80% or higher, the statement was regarded as accepted. The members of the consensus team consider that this guideline would be valuable to inform clinical practice, teaching, and research on SIBO in the Asian-Pacific region as well as in other countries.

Adding a liquid test meal to a standardized lactulose hydrogen breath test significantly influences abdominal symptom generation and hydrogen values

OBJECTIVE

While single sugar tests are controversially discussed, combination tests with meals are gaining more attention. The aim of this study was to analyze the impact of adding a test meal to lactulose hydrogen breath tests (LHBT) on hydrogen values and abdominal symptoms in patients with functional gastrointestinal disorders (FGIDs).

METHODS

Data of 81 FGID patients between 2014-2018 were analyzed. Patients underwent LHBT with 30 g lactulose + 300 mL water and a nutrient challenge test (NCT) including 400 mL liquid test meal + 30 g lactulose. To statistically assess the effect of a test meal on abdominal symptoms and H2, mixed-effect models were used.

RESULTS

Adding a test meal to LHBT showed a significant increase in nausea [odds ratio (OR) 1.4; 95% confidence interval (CI), 1.1-1.7], decrease in abdominal pain (OR 0.7; 95% CI, 0.6-0.9), borborygmi (OR 0.5; 95% CI, 0.4-0.6), diarrhea (OR 0.4; 95% CI, 0.3-0.6), and H2 production (estimate -5.3, SE 0.7, P < 0.001). The effect on bloating was only significant in functional dyspepsia, irritable bowel syndrome-functional dyspepsia mixed type and functional abdominal pain/bloating (OR 0.1; 95% CI, 0.0-0.2; OR 1.7; 95% CI, 1.2-2.3 resp OR 4.4; 95% CI, 1.8-10.6).

CONCLUSIONS

Significant effects on abdominal symptoms and H2 production by adding a test meal to LHBT in FGID patients are shown. Increased occurrence of nausea may be caused by gastric/duodenal hypersensitivity; decreased H2, diarrhea and borborygmi by slower and more physiologic gastric emptying resulting in later arrival of the test substance in the bowel. We recommend NCTs instead of LHBT to more physiologically represent FGID patients' meal-induced burden.

Kynurenine Pathway of Tryptophan Metabolism in Migraine and Functional Gastrointestinal Disorders

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation.

Small Intestinal Bacterial Overgrowth in Functional Dyspepsia: A Systematic Review and Meta-Analysis

INTRODUCTION

This systematic review and meta-analysis aimed to determine the role of small intestinal bacterial overgrowth (SIBO) in patients with functional dyspepsia (FD).

METHODS

Electronic databases were searched until July 2020 for studies reporting prevalence of SIBO in FD. The prevalence rates, odds ratio, and 95% confidence intervals (CIs) of SIBO in FD and controls were calculated.

RESULTS

Seven studies with 263 patients with FD and 84 controls were identified. The odds for SIBO in patients with FD were significantly higher as compared to that in controls (odds ratio = 4.3, 95% CI, 1.1-17.5, 4 studies, 234 participants); however, there was moderate heterogeneity in this analysis. Including high-quality, case-control studies (all using glucose breath tests [GBTs]), the risk of SIBO in patients with FD as compared to controls was 2.8 higher (95% CI 0.8-10.0, 3 studies, 200 participants) with minimal heterogeneity in this analysis. Using the lactulose breath test, SIBO prevalence in FD was significantly higher (53.4%, 95% CI 33.9-71.9, 3 studies, 110 participants) as compared to that with GBT (17.2%, 95% CI 8.6-31.6, 4 studies, 153 participants). Substantial heterogeneity was found in studies using the lactulose breath test but not in studies using GBT. There was no significant difference in SIBO prevalence in patients with FD according to FD subtype.

DISCUSSION

This meta-analysis suggests a link between FD and SIBO. The quality of evidence is low and can be largely attributed to the type of breath test for SIBO diagnosis and clinical heterogeneity. More appropriately designed studies are required to confirm the link between SIBO and FD.

Inflammation and Overlap of Irritable Bowel Syndrome and Functional Dyspepsia

Irritable bowel syndrome (IBS) and functional dyspepsia (FD) are common functional gastrointestinal disorders (FGIDs) and account for a large proportion of consulting patients. These 2 disorders overlap with each other frequently. The pathogenesis of IBS or FD is complicated and multi-factors related, in which infectious or non-infectious inflammation and local or systemic immune response play significant roles. There are few studies focusing on the mechanism of inflammation in patients with overlap syndrome of irritable bowel syndrome and functional dyspepsia (IBS-FD). This review focuses on current advances about the role of inflammation in the pathogenesis of IBS and FD and the possible mechanism of inflammation in IBS-FD.

Lactose Sensitivity and Lactose Malabsorption: The 2 Faces of Lactose Intolerance

Background/Aims

Self-reported lactose intolerance (LI) is frequent in patients with functional bowel disorders (FBD) that could be interpreted as irritable bowel syndrome (IBS). The present study aims to characterize the responses of patients with FBD, without small intestinal bacterial overgrowth (SIBO), and LI, in terms of lactose malabsorption (LM) and lactose sensitivity (LS) according to psychological and clinical features.

Methods

One hundred and fifty-eight consecutive FBD outpatients with LI, and no SIBO, were classified according to the Rome III questionnaire and filled Beck Depression Inventory, and State and Trait Anxiety questionnaires. They underwent a lactose tolerance test in which glycemia during 60 minutes and digestive symptoms for 3 hours were recorded.

Results

Abnormal lactose tolerance tests were found in 110 patients (70%), 44 (28%) with LM, 96 (61%) with LS, and 30 (19%) having both LM and LS. LM patients had a higher frequency of functional diarrhea (P = 0.040) and a lower frequency of dysphagia (P = 0.031). LS patients had a higher depression score (P = 0.007), higher frequency of globus (P = 0.042), irritable bowel syndrome (IBS) (P = 0.027) and mixed IBS (P = 0.049), and lower frequency of abdominal pain (P = 0.040). LS was significantly associated with a higher depression score (P = 0.002), and a higher frequency of globus (P = 0.046).

Conclusions

Thirty percent of LI patients have normal lactose absorption and normal LS. In the other 70% of patients, LI could be associated with LM and/or LS.

Evaluation of main functional dyspepsia symptoms after probiotic administration in patients receiving conventional pharmacological therapies

Objective

Postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) are the two main forms of functional dyspepsia (FD). Probiotics are a promising therapy for FD, but current data remains heterogeneous. This work aims to evaluate a probiotic combination of Lacticaseibacillus rhamnosus LR04 (DSM 16605), Lactiplantibacillus pentosus LPS01 (DSM 21980), Lactiplantibacillus plantarum LP01 (LMG P-21021), and Lactobacillus delbrueckii subsp. delbruekii LDD01 (DMS 22106), alone or together with other pharmacological therapies, for clinical improvement of symptoms associated with FD.

Methods

Patients with FD were enrolled and divided into two groups: PDS and EPS. Probiotic alone or combined with prokinetics, antacids, or proton-pump-inhibitors were administered for 30 days. A progressive-score scale was used to evaluate symptoms in all patients at the beginning of the trial and at 15 days after the end of treatment.

Results

A cohort of 2676 patients were enrolled (1 357 with PDS; 1 319 with EPS). All patients showed significant improvements in dyspeptic symptoms following treatment. In patients with PDS, probiotic alone resulted in the lowest prevalence of symptoms following treatment, while patients with EPS showed no clear between-treatment differences.

Conclusions

Dyspeptic symptoms were reduced following treatment in all patients.

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

BACKGROUND

Clinical symptoms of patients with small intestinal bacterial overgrowth (SIBO) may overlap with symptoms of gastroparesis. Prior studies suggest delayed small intestinal transit is associated with SIBO, but have not shown an association between delayed gastric emptying and SIBO. However, these studies have generally relied on the indirect method of breath testing to diagnose SIBO.

AIMS

The aim of this study was to examine the association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy.

METHODS

In a single-center retrospective study of previous research participants who presented for small bowel enteroscopy for diagnostic evaluation of SIBO, we identified 73 participants who underwent gastric emptying study by scintigraphy. A microbiological diagnosis of SIBO was made in patients based on culture results of jejunal aspirates. Clinical symptoms were assessed using the total gastroparesis cardinal symptom index (GCSI) score. We compared delayed gastric emptying, 2- and 4-h gastric retention, and gastroparesis symptoms between patients with and without a microbiological diagnosis of SIBO.

KEY RESULTS

Among 29 participants with SIBO and 44 without SIBO, 33 (45%) had evidence of delayed gastric emptying. There was no significant association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. Percent retained at 2 and 4 h, and total GCSI scores did not differ significantly between those with and without SIBO.

CONCLUSIONS

Although delayed gastric emptying is common in patients with suspected SIBO, gastric emptying is not associated with a microbiological diagnosis of SIBO.

Management of small intestinal bacterial overgrowth by pediatric gastroenterologists in Spain

BACKGROUND

small intestinal bacterial overgrowth (SIBO) is a heterogeneous condition with nonspecific symptoms. This study aimed to report its management by pediatric gastroenterologists in Spain.

METHODS

a descriptive study was performed by means of a survey sent to 184 active members of the Spanish Society of Pediatric Gastroenterology, Hepatology and Nutrition (SEGHNP).

RESULTS

one hundred and forty-eight responses (80.4 %) were received. Forty-four patients had no predisposing condition, 31.1 % used antibiotics followed by probiotics, 33.1 % antibiotherapy concomitant with probiotics, 24.3 % only antibiotics and 10.8 % only probiotics. The diagnosis was established via clinical parameters in 73.8 % of participants and the therapeutic response was checked only by clinical data in 90 %.

CONCLUSIONS

there is high variability in the management of SIBO among pediatric population in Spain.

[Prevalence of small bowel bacterial overgrowth in patients with functional dyspepsia: a meta-analysis]

AIM

Systematization of data on the frequency of detection of the syndrome of bacterial overgrowth in the small intestine (SIBO) in patients with functional dyspepsia (FD).

MATERIALS AND METHODS

MEDLINE/PubMed, EMBASE, Cochrane, Google Scholar, the Russian Science Citation Index (RSCI) through July 2020 were searched to identify studies evaluating the prevalence of SIBO in FD. In addition, a search for relevant abstracts was carried out in the electronic databases of the United European Gastroenterology Week (UEG), American College of Gastroenterology (ACG), International Conference on Nutrition and Food (ICNF). For the final analysis, publications were selected that used validated tests for the assessment of SIBO (hydrogen breath test using glucose or lactulose) with detailed descriptive statistics, allowing the resulting data to be included in the meta-analysis.

RESULTS

The final analysis included 7 studies with 1248 patients with FD. Overall pooled prevalence of SIBO in patients with FD was 34.73% (95% CI 24.80745.383). There was significant heterogeneity between the results (p0.0001; I2=89.91%). When excluded from the meta-analysis of a study in which the incidence of SIBO was studied in patients with refractory FD, the pooled prevalence was 38.98% (95% CI 28.96449.490).

CONCLUSION

This meta-analysis has demonstrated that SIBO is often associated with FD and is observed in about every third patient with this functional gastrointestinal tract disease.

Asymptomatic Duodenitis and Helicobacter pylori associated Dyspepsia in 2-Year-Old Chronic Malnourished Bangladeshi Slum-Dwelling Children: A Cross-Sectional Study

AIM

There is insufficient knowledge on the * duodenal histology and Helicobacter pylori infection in malnourished Bangladeshi children. Therefore, we attempted to explore the prevalence of H. pylori infection and duodenal histopathology in 2-year-old chronic malnourished Bangladeshi slum-dwelling children and investigate their association with dyspeptic symptoms.

METHODS

This cross-sectional study was conducted using the data of the Bangladesh Environmental Enteric Dysfunction study in an urban slum of Dhaka, Bangladesh. With a view to address the association of environmental enteric dysfunction (EED) with stunting, upper gastrointestinal endoscopy was performed on 54 chronic malnourished children {31 stunted [length-for-age Z-scores (LAZ) <-2] and 23 at risk of stunting (LAZ <-1 to -2)} aged between 12-24 months and the mucosal biopsies were subjected to histopathological examination after obtaining proper clinical history. Stool antigen for H. pylori (HpSA) was assessed to determine H. pylori status.

RESULTS

In all, 83.3% (45/54) of the children had histopathological evidence of duodenitis. Chronic mild duodenitis was found to be the most prevalent form of duodenitis (53.7%) in the children. Only 8.9% (4/45) of the children with duodenitis had dyspepsia (p < 0.05). The 14.8% (8/54) of the children were found positive for H. pylori infection. Logistic regression analysis revealed children positive for HpSA had significant association with dyspepsia (OR 9.34; 95% CI 1.54-56.80).

CONCLUSIONS

The number of chronic malnourished children suffering from duodenitis was found to be very high. Majority of these children was asymptomatic. Children positive for HpSA had significant association with dyspeptic symptoms.

High Prevalence of Small Intestinal Bacterial Overgrowth among Functional Dyspepsia Patients

BACKGROUND

Small intestinal bacterial overgrowth (SIBO), characterized by either increased numbers or presence of colonic type bacteria in the small bowel has been previously described in functional dyspepsia (FD), based on breath testing. In this study, we aim to examine the prevalence of SIBO among FD patients using small bowel aspirate culture.

METHODS

We prospectively enrolled outpatients fulfilling Rome IV criteria for FD. Severity of symptoms was graded using the patient assessment of upper gastrointestinal symptom severity index (PAGI-SYM) questionnaire. Patients underwent upper gastrointestinal endoscopy and duodenal fluid was aspirated in sterile traps. SIBO was defined as ≥103 colony forming units/mL of duodenal aspirate and/or presence of colonic type bacteria. Patients undergoing gastroscopy due to gastroesophageal reflux symptoms - control group (CG) - and patients with irritable bowel syndrome (IBS) fulfilling Rome IV criteria were also recruited.

RESULTS

We enrolled 227 FD subjects, 30 CG, and 90 IBS patients. Among FD patients, 144 (63.4%), 64 (28.2%), and 19 (8.4%) had postprandial distress syndrome (PDS), epigastric pain syndrome (EPS), and overlapping PDS-EPS syndrome, respectively. SIBO prevalence was 20.8%, 12.5%, and 31.6% among PDS, EPS, and overlapping PDS-EPS FD subtypes, respectively. Overall, SIBO prevalence was significantly higher in FD (44/227 [19.4%]) compared to CG (1/30 [3.3%]) (p = 0.037) and similar to IBS (44/227 [19.4%] vs. 15/90 [16.7%], p = 0.63) subjects. SIBO presence was associated neither with total nor with any subscale score of the PAGI-SYM questionnaire.

CONCLUSION

In a cohort of Greek FD patients, SIBO prevalence was similar to that of IBS subjects and higher compared to that of controls.

Duodenal and rectal mucosal microbiota related to small intestinal bacterial overgrowth in diarrhea-predominant irritable bowel syndrome

BACKGROUND AND AIM

Small intestinal bacterial overgrowth (SIBO) has been proposed as an etiologic factor in irritable bowel syndrome, particularly the diarrhea-predominant subtype (IBS-D). We aimed to identify potential intestinal microbial pattern in IBS-D patients with SIBO.

METHODS

Diarrhea-predominant irritable bowel syndrome patients fulfilling Rome III criteria were recruited and randomly divided into an exploratory cohort (57 cases) and a validation cohort (20 cases). SIBO was identified according to standard glucose hydrogen breath test. For 16S rRNA gene sequencing, samples of duodenal mucosa, duodenal fluid, rectal mucosa, and fresh feces were collected and performed. The α and β diversity, as well as differences in microbial composition and function, in SIBO⁺ and SIBO^- IBS-D subjects were evaluated.

RESULTS

The microbial diversity and composition obviously differed between SIBO⁺ and SIBO^- IBS-D in duodenal and rectal mucosa but not in duodenal fluid and fresh feces. For rectal mucosal microbiota, it displayed markedly reduced aerobe and Gram-negative bacteria and increased facultative anaerobe and Gram-positive bacteria, moreover, altered functions of microbial metabolism in SIBO⁺ IBS-D. Significantly higher rectal mucosa-related microbial dysbiosis index was observed in SIBO⁺ IBS-D, and a cut-off value at -0.37 had a sensitivity of 56.55% and specificity of 90.91% to identify the SIBO in IBS-D subjects.

CONCLUSIONS

Mucosal microbiota, rather than luminal bacteria, has a more apparent dysbiosis in SIBO⁺ IBS-D patients relative to those without SIBO. Rectal mucosa-associated microbiota may act as a potential predictor of SIBO in IBS-D patients.

Efficacy and Safety of Probiotics, Prebiotics and Synbiotics in the Treatment of Irritable Bowel Syndrome: A systematic review and meta-analysis

Treatments that target alterations in gut microbiota may be beneficial for patients with irritable bowel syndrome (IBS). A systematic review and meta-analysis was conducted of randomised clinical trials (RCTs) evaluating the efficacy and safety of probiotics, prebiotics and synbiotics. Factors considered in the analysis included global IBS symptoms and/or abdominal pain, secondary symptoms and the frequency of adverse events. A total of 33 RCTs involving 4,321 patients were identified. Overall, probiotics significantly improved global IBS symptoms compared to placebos (standardised mean difference = −0.32, 95% confidence interval: −0.48 to −0.15; P <0.001), with significant heterogeneity between studies (I² = 72%; P <0.001). This remained apparent in both single- and multi-strain probiotic interventions as well as synbiotic formulations. However, evidence regarding prebiotics was scarce. There were no significant inter-group differences in terms of the frequency of adverse events. Future RCTs should address methodological limitations, including short follow-up periods and patient adherence.

Efficacy of prebiotics and probiotics for functional dyspepsia: A systematic review and meta-analysis

BACKGROUND

Functional dyspepsia (FD) is a functional gastrointestinal disorder. Evidence suggests that disturbance of the gastrointestinal microbiota may be implicated in FD. We performed a systematic review and meta-analysis to examine the efficacy of prebiotics and probiotics for FD.

METHODS

MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (through September 2018). Randomized controlled trials (RCTs) that recruited adults with FD and that compared prebiotics, probiotics, or synbiotics with placebo or no therapy were eligible. Eligibility assessment and data extraction were performed by two independent researchers. Dichotomous symptom data were pooled to obtain a relative risk (RR) with a 95% confidence interval (CI) of remaining symptomatic after therapy. Continuous data were pooled using a standardized or weighted mean difference with a 95% CI.

RESULTS

The search strategy identified 1062 citations. Five RCTs were eligible for inclusion. The RR of FD symptoms improving with probiotics or probiotics vs placebo was 1.15 (95% CI 1.01-1.30). Probiotics and prebiotics had beneficial effects on symptom scores of FD. Data for synbiotics in the context of FD were sparse, and no definite conclusions could be drawn.

ETHICS AND DISSEMINATION

This study belongs to the category of systematic reviews, not clinical trials. Therefore, it does not require ethical approval. The results of this study will be published in influential international academic journals related to this topic.

CONCLUSION

Probiotics and prebiotics seemed to be effective treatments for FD, although the individual species and strains that are the most beneficial remain unclear. Using only probiotics failed to improve the symptoms of FD. Further evidence is required before the role of probiotics, prebiotics, and synbiotics in FD can be fully understood.

Lactulose Breath Testing Can Be a Positive Predictor Before Weight Gain in Participants with Obesity Submitted to Roux-en-Y Gastric Bypass

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is defined as the colonization of fermentative bacteria in the duodenum and jejunum. The alteration of digestive anatomy promoted by bariatric surgery may be a pre-disposing factor for SIBO. In this context, the prevalence of SIBO in participants undergoing bariatric surgery using Roux-en-Y gastric bypass (BGYR) was evaluated.

METHODS

Participants, both sexes, older than 18 years, were those who (a) had bariatric surgery by the BGYR technique at least 1 year before the data collection and (b) did not use antibiotics recently. The SIBO diagnosis was established through the hydrogen breath test (H₂BT), with intake of lactulose and serial collection of breath samples over 2 h. A test with ≥ 12-point elevation over the basal sample at 60 min after substrate intake was deemed positive.

RESULTS

A total of 18 participants (14 females (77.8%)) were enrolled with a mean age of 50.5 years (range, 23 to 79 years). The interval between surgery and data collection ranged from 5 to 20 years (mean, 11.2 years). The mean preoperative body mass index (BMI) was 44.6 kg/m² (range, 36.7-56.2 kg/m²). The H₂RT with lactulose was positive for SIBO in seven (six female) participants. The participants with negative test measured trough H₂BT with lactulose had a lower mean BMI of 28.69 kg/m², in comparison with the positive group, which presented a mean BMI of 33.04 kg/m² (p value = 0.041).

CONCLUSION

Our data point to a high prevalence of SIBO (38.8%) in patients undergoing BGYR with a value in accordance with the literature. Moreover, the differences in BMI between negative and positive groups by H₂BT with lactulose evidenced a weight gain relapse in participants with SIBO.

Preparation methods for animal models of diarrhea with gastrointestinal food stagnation syndrome: A review

Gastrointestinal food stagnation syndrome, also known as dyspeptic retention syndrome, is a syndrome that some high-protein, high-calorie food cannot be digested normally and is retained in the gastrointestinal tract. Food retention in the gastrointestinal tract is likely to cause internal heat, resulting in diarrhea or constipation. This paper provides an overview of gastrointestinal food stagnation syndrome, its animal models, intestinal microecological characteristics, and treatment of diarrhea with gastrointestinal food stagnation syndrome, in order to provide a reference for the clinical diagnosis and treatment of this disorder.

Breath Hydrogen Testing in East and Southeast Asia

Breath hydrogen tests are popular, noninvasive tests for the assessment of carbohydrate fermentation in patients with irritable bowel syndrome (IBS) and functional dyspepsia (FD). There is limited information regarding the utility of breath hydrogen and methane tests in IBS and FD patients in East and Southeast Asia. This review aims to summarize current literature about common indications of breath testing in this region, the genesis of functional gastrointestinal symptoms by provocative breath testing and provide suggestions for correct use. The most common testing indication is the assessment of lactose intolerance, followed by small intestinal bacterial overgrowth (SIBO) and differentiation of intestinal gas profiles in research setting. Studies in this region not only documented a high prevalence of lactose malabsorption but a population, both healthy and IBS, that is highly symptomatic to typical lactose intakes. Breath hydrogen assessment of other fermentable carbohydrates (FODMAPs) are fairly uncommon, whereas methane breath testing is almost nonexistent. Cumulative hydrogen production following lactulose was also not excessive in IBS patients compared with controls. The evidence however, for the detection of SIBO suggests limited reliability in the use of lactulose or glucose breath testing alone and inconclusive data on its correlation with symptoms. Conversely, little has been carried out in FD. In conclusion, breath testing should be limited in the predicting patients with SIBO for directing clinical management but can be considered in the objective assessment of lactose malabsorption within a low FODMAP diet. Recommendations to improve the interpretation of breath testing in research were also provided.

Gut Microbiota-Based Therapies for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, heterogeneous disorder characterized by abdominal pain associated with changes in bowel habits. The pathogenesis of IBS is multifactorial and may relate to alterations in the gut microbiota, changes in visceral sensation and motility, and genetic and environmental factors. Administration of systemic antibiotics may increase the risk of IBS by altering gastrointestinal homeostasis. Therapeutic interventions for IBS with diarrhea that are thought to target alterations in the gut microbiota include the nonsystemic antibiotic rifaximin, the medical food serum-derived bovine immunoglobulin, prebiotics, probiotics, and dietary modification. SYN-010 is a modified-release statin formulation that reduces methane production by Methanobrevibacter smithii and is currently in development for the treatment of patients with constipation-predominant IBS. Use of these interventions in the management of patients with IBS may function to restore a healthy gut microbiota and ameliorate symptoms of IBS.

Is It Useful to Administer Probiotics Together With Proton Pump Inhibitors in Children With Gastroesophageal Reflux?

Background/Aims

Gastroesophageal reflux disease (GERD) is a frequent condition diagnosed in children and treated with proton pump inhibitors (PPI). Long-term PPI administration can alter intestinal bacterial population by suppressing the gastric acid barrier and may cause diarrhea. The aim of this study is to evaluate the prevalence of small intestinal bacterial overgrowth assessed by glucose hydrogen breath test among children that received 12 weeks of PPI with or without probiotics (Lactobacillus reuteri DSM 17938) associated, compared to controls.

Methods

Glucose hydrogen breath test was performed before PPI treatment and after 12 weeks of PPI treatment to 128 consecutive children with GERD (1–18 years old) and a control group (120 healthy children). The children with GERD were randomized into 2 groups: placebo group (64 who received PPI and placebo for 12 weeks) and probiotics group (64 who received PPI and probiotics for 12 weeks).

Results

After 12 weeks of treatment, dysbiosis was detected among 56.2% of children from placebo group (36/64), compared to 6.2% of children from the probiotics group (4/64, P < 0.001). Bacterial overgrowth was detected in 5% of controls (6/120). Probiotics group had a lower prevalence of dysbiosis, similar to controls (P = 0.740).

Conclusion

Probiotics administration decreased the rate of dysbiosis among children treated with PPI.

Functional dyspepsia

Functional dyspepsia is one of the most prevalent functional gastrointestinal disorders. Functional dyspepsia comprises three subtypes with presumed different pathophysiology and aetiology: postprandial distress syndrome (PDS), epigastric pain syndrome (EPS) and a subtype with overlapping PDS and EPS features. Functional dyspepsia symptoms can be caused by disturbed gastric motility (for example, inadequate fundic accommodation or delayed gastric emptying), gastric sensation (for example, sensations associated with hypersensitivity to gas and bloating) or gastric and duodenal inflammation. A genetic predisposition is probable but less evident than in other functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Psychiatric comorbidity and psychopathological state and trait characteristics could also play a part, although they are not specific to functional dyspepsia and are less pronounced than in IBS. Possible differential diagnoses include Helicobacter pylori infection and peptic ulceration. Pharmacological therapy is mostly based on the subtype of functional dyspepsia, such as prokinetic and fundus-relaxing drugs for PDS and acid-suppressive drugs for EPS, whereas centrally active neuromodulators and herbal drugs play a minor part. Psychotherapy is effective only in a small subset of patients, whereas quality of life can be severely affected in nearly all patients. Future therapies might include novel compounds that attempt to treat the underlying gastric and duodenal inflammation.

Is Helicobacter pylori Associated Functional Dyspepsia Correlated With Dysbiosis?

BACKGROUND/AIMS

To assess the long-term effect of Helicobacter pylori eradication on symptomatic improvement according to the type of antibiotic and the duration of treatment in H. pylori-associated functional dyspepsia.

METHODS

We searched Pubmed, Embase, CINAHL, and the Cochrane library databases for randomized controlled trials written in English and undertaken up to August 2016 that met our eligibility criteria. The search methodology used combinations of the following keywords: Helicobacter pylori OR H. pylori OR HP; dyspepsia OR functional dyspepsia OR non-ulcer dyspepsia; eradication OR cure OR treatment. The study outcome was the summary odds ratio (OR) for symptomatic improvement in H. pylori-associated functional dyspepsia with successful eradication therapy. Subgroup analyses were performed based on the type of antibiotic, and the duration of treatment, whether or not patients had symptoms of irritable bowel syndrome, and on race.

RESULTS

Sixteen randomized controlled trials met the inclusion criteria. The summary OR for symptomatic improvement in patients in our eradication group was 1.33 (95% confidence interval [CI], 1.16-1.54; P < 0.01). In a subgroup analysis on type of antibiotic, symptomatic improvement with metronidazole-containing regimen (OR, 1.87; 95% CI, 1.26-2.77) was better than treatment with clarithromycin (OR, 1.29; 95% CI, 1.11-1.50). H. pylori eradication therapy given for 10-14 days was the more effective for symptom improvement than 7-day therapy. When the studies excluding irritable bowel syndrome cases were analyzed, there were no therapeutic effects of H. pylori eradication on symptomatic improvement.

CONCLUSIONS

In the clinical setting, the most effective H. pylori eradication regimen for functional dyspepsia to provide relief of symptoms is a metronidazole-based treatment regimen for at least 10 days. The explanation for this is that H. pylori-associated functional dyspepsia could be associated with dysbiosis.

Superior Mesenteric Artery Syndrome May Be Overlooked in Women with Functional Dyspepsia

Objective Superior mesenteric artery (SMA) syndrome is characterized by the compression of the third segment of the duodenum between the SMA and aorta, resulting in duodenal obstruction. Because the symptoms of the syndrome are similar to those of functional dyspepsia (FD), this study aimed to examine whether or not patients with SMA syndrome were present among those diagnosed with FD. Methods Patients with an FD diagnosis underwent measurement of the angle and distance between the SMA and aorta by ultrasonography or computed tomography. Patients with an angle of ≤22° or with a distance of ≤8 mm between the SMA and aorta were diagnosed with SMA syndrome. Bacterial culture of the duodenal aspirate was also performed. Results Of the 46 FD patients, 5 (11%) met the criteria. All 5 were women with a body mass index significantly lower than the remaining 41 patients (18.7 vs. 24.0 kg/m², p=0.003). In addition, all 5 patients had 10⁵/mL or more bacteria in the duodenum. The symptoms of these five patients were treated through dietary and postprandial posture counselling with or without medication. Conclusion Patients with SMA syndrome were observed among underweight women diagnosed with FD. Their symptoms may be associated with bacterial overgrowth.

Serial Frozen Fecal Microbiota Transplantation in the Treatment of Chronic Intestinal Pseudo-obstruction: A Preliminary Study

Background/Aims

Chronic intestinal pseudo-obstruction (CIPO) is a serious, life-threatening motility disorder that is often related to bacterial overgrowth. Fecal microbiota transplantation (FMT) results in restoration of the normal intestinal microbial community structure. We investigated the efficacy of FMT in the treatment of CIPO patients.

Methods

Nine patients (age 18–53 years) with CIPO were enrolled in this prospective, open-label study. Patients received FMT for 6 consecutive days through nasojejunal (NJ) tubes and were followed up for 8 weeks after treatment. We evaluated the rate of clinical improvement and remission, feeding tolerance of enteral nutrition, and CT imaging scores of intestinal obstructions. Lactulose hydrogen breath tests were performed before FMT and 8 weeks after FMT to evaluate for the presence small intestinal bacterial overgrowth (SIBO).

Results

FMT significantly alleviated bloating symptoms, and symptoms of pain were relieved 2 weeks after FMT. Enteral nutrition administered through a NJ tube after FMT was well-tolerated by 66.7% (6/9) of patients. CT scores of intestinal obstructions were significantly reduced after FMT (P = 0.014). SIBO was eliminated in 71.0% (5/7) of patients.

Conclusions

This pilot study demonstrated the safety of using FMT. FMT may relieve symptoms in selected patients with CIPO. FMT may also improve patient tolerance of enteral nutrition delivered via a NJ tube.

PREVALENCE OF SMALL INTESTINE BACTERIAL OVERGROWTH IN PATIENTS WITH GASTROINTESTINAL SYMPTOMS

BACKGROUND

Small intestine bacterial overgrowth is a heterogeneous syndrome characterized by an increase in the number and/or the presence of atypical microbiota in the small intestine. The symptoms of small intestine bacterial overgrowth are unspecific, encompassing abdominal pain/distension, diarrhea and flatulence. Due to the increased cost and complexity for carrying out the jejunal aspirate, the gold standard for diagnosis of the syndrome, routinely the hydrogen (H 2 ) breath test has been used, utilizing glucose or lactulose as substrate, which is able to determine, in the exhaled air, the H 2 concentration produced from the intestinal bacterial metabolism. However, due to a number of individuals presenting a methanogenic microbiota, which does not produce H 2 , the testing on devices capable of detecting, concurrently, the concentration of exhaled H 2 and methane (CH 4 ) is justified.

OBJECTIVE

This study aimed to determine the prevalence of small intestine bacterial overgrowth in patients with digestive symptoms, through a comparative analysis of breath tests of H 2 or H 2 and CH 4 associated, using glucose as substrate .

METHODS

A total of 200 patients of both sexes without age limitation were evaluated, being directed to a Breath Test Laboratory for performing the H 2 test (100 patients) and of exhaled H 2 and CH 4 (100 patients) due to gastrointestinal complaints, most of them patients with gastrointestinal functional disorders.

RESULTS

The results indicated a significant prevalence of small intestine bacterial overgrowth in the H 2 test and in the test of exhaled H 2 and CH 4 (56% and 64% respectively) in patients with gastrointestinal symptoms, and higher prevalence in females. It found further that methane gas was alone responsible for positivity in 18% of patients.

CONCLUSION

The data found in this study is consistent with the findings of the current literature and underscores the need for using devices capable of capturing the two gases (exhaled H 2 and CH 4 ) to improve the sensitivity and hence the accuracy of small intestine bacterial overgrowth diagnosis in daily medical practice.

New insights in IBS-like disorders: Pandora's box has been opened; a review

The most complained gastrointestinal symptoms are chronic diarrhea, bloating and abdominal pain. Once malignancies and inflammatory bowel diseases are excluded, irritable bowel syndrome (IBS) and the so called "IBS-like disorders" should be taken into account. The relationship between IBS as defined by Rome IV criteria and these clinical conditions is sometimes obscure, since many IBS patients identify food as a possible trigger for their symptoms. Here, we discuss IBS and the most common IBS-like disorders (celiac disease, non-celiac gluten sensitivity, fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), lactose intolerance, small intestinal bacterial overgrowth (SIBO), α-amylase/trypsin inhibitor (ATIs), nickel allergic contact mucositis), focusing on epidemiologic, clinical, diagnostic and therapeutic aspects. Given the lack of specificity of symptoms, clinical investigation will be facilitated by awareness of these disorders as well as new specific diagnostic tools.

The Role of Duodenal Inflammation in Functional Dyspepsia

Functional dyspepsia (FD) is common and significantly impairs quality of life. Symptoms of FD are considered to originate from the gastroduodenal region, classified by the Rome criteria as disorders of brain-gut interaction without structural alteration. However, it is now apparent that FD is a number of syndromes, the epigastric pain syndrome (bothersome epigastric pain or epigastric burning) and the postprandial distress syndrome (with bothersome postprandial fullness or early satiation) and there are wide-ranging symptoms and severity. The origin of these troublesome symptoms is now considered to be a result of disrupted gastroduodenal neuropathophysiology. The complexity of the syndrome indicates that there must be different triggers, supported by the limited efficacy of the many treatments available. Current research based on evidence by association suggests that duodenal contents, including the duodenal microbiome, pathogens, and allergy may be triggers of FD. Recent studies have also shown that systemic responses of increased circulating lymphocytes and elevated proinflammatory cytokines and subtle inflammation in the duodenum may accompany the onset and persistence of symptoms. This inflammatory phenotype is characterized by innate inflammation, an eosinophil infiltrate in the duodenum in FD in those with postprandial distress syndrome. Routine histopathology practice does not quantify these cells so the status of FD is not yet appreciated as an inflammatory condition. Thus functional is becoming inflammatory and this breakthrough in understanding that functional does not necessarily mean no, but subtle pathology, may improve therapeutic options, which are currently aimed at symptom relief rather than targeted at underlying pathology.

Upper gastrointestinal dysmotility and small intestinal bacterial overgrowth in patients with functional constipation

AIM

To explore the association between upper and lower gastrointestinal (GI) motility, as well as that between small intestinal bacterial overgrowth (SIBO) and abdominal symptoms in patients with functional constipation (FC).

METHODS

Consecutive patients with FC who met Rome III criteria were enrolled. The symptoms of constipation were assessed by the patient assessment of constipation symptom (PAC-SYM) questionnaire. All subjects underwent lactulose hydrogen breath test (LHBT) and colonic transit test. The association between delayed colonic transit time (CTT) and delayed orocecal transit time (OCTT), as well as that between delayed OCTT and SIBO were investigated. Abdominal symptom scores were compared between the SIBO positive and negative groups.

RESULTS

Forty-five patients were enrolled. Twenty-five patients had delayed CTT and 19 had delayed OCTT. The SIBO positive rate in FC patients was 44.4%. The frequency of delayed OCTT was significantly higher in the delayed CTT group than in the normal CTT group (P = 0.036). The delayed OCTT group rated more occurrence of SIBO (P < 0.001). There was a significant difference in bloating symptom score between the SIBO positive and negative groups (P = 0.043).

CONCLUSION

FC patients may also have upper GI dysmotility. SIBO may be associated with delayed OCTT and may aggravate the bloating symptom in FC patients.

Utility of wireless motility capsule and lactulose breath testing in the evaluation of patients with chronic functional bloating

BACKGROUND

The precise aetiology of chronic bloating remains poorly understood and underlying gastroparesis, small bowel bacterial overgrowth and colonic inertia may, individually or collectively, play a role.

AIMS

In this retrospective cohort analysis of symptomatic patients with chronic persistent bloating, we determined the clinical utility of wireless motility capsule and lactulose breath test in further defining the underlying aetiology for functional bloating.

METHODS

Consecutive patients with chronic bloating underwent clinical assessment, wireless motility capsule testing and lactulose breath testing using standard protocols.

RESULTS

52 patients qualified for inclusion in this analysis, fulfilling Rome III criteria for functional bloating. Most patients (54%) had an abnormal wireless motility capsule study; of those, 11.5% had evidence of gastroparesis, 7.7% had small bowel transit delay, 15.8% had colonic inertia, 3.8% had delayed gastric and small bowel transit, 5.6% had combined gastric and colonic transit delay, 3.8% had delayed small bowel and colonic transit, and 5.6% had delayed gastric, small bowel and colon transit times. Using clinical questionnaires the median scores for bloating, constipation and eructation were not significantly different. Neither constipation nor eructation was specific to gastroparesis or colonic inertia but bloating was numerically more prevalent and severe in patients with delayed small bowel transit. 40% of patients had positive lactulose breath test but had no distinguishing clinical characteristics.

CONCLUSIONS

Chronic functional bloating may reflect underlying gastroparesis, small intestinal bacterial overgrowth or colonic inertia. Wireless motility capsule and lactulose breath test are useful in the assessment of patients with bloating and should be considered during evaluation.

Clinical drugs for reflux esophagitis

Reflux esophagitis (RE) is a common clinical disease with complex etiology and high incidence which is increasing year by year. Although conventional treatments can ease patients' symptoms, the long-term prognosis is unsatisfactory with many adverse reactions and recurrent symptoms. This article discusses the physiological functions, therapeutic effects and combined application of clinical drugs for reflux esophagitis, with an aim to provide guidance for the treatment of this disease.

Changes in patients’ symptoms and gastric emptying after Helicobacter pylori treatment

AIM: To investigate the changes in clinical symptoms and gastric emptying and their association in functional dyspepsia (FD) patients.

METHODS: Seventy FD patients were enrolled and divided into 2 groups Helicobacter pylori (H. pylori)-negative group (28 patients), and H. pylori-positive group (42 patients). Patients in the H. pylori-positive group were further randomly divided into groups: H. pylori-treatment group (21 patients) and conventional treatment group (21 patients). Seventy two healthy subjects were selected as the control group. The proximal and distal stomach area was measured by ultrasound immediately after patients took the test meal, and at 20, 40, 60 and 90 min; then, gastric half-emptying time was calculated. The incidence of symptoms and gastric half-emptying time between the FD and control groups were compared. The H. pylori-negative and conventional treatment groups were given conventional treatment: domperidone 0.6 mg/(kg/d) for 1 mo. The H. pylori-treatment group was given H. pylori eradication treatment + conventional treatment: lansoprazole 30 mg once daily, clarithromycin 0.5 g twice daily and amoxicillin 1.0 g twice daily for 1 wk, then domperidone 0.6 mg/(kg/d) for 1 mo. The incidence of symptoms and gastric emptying were compared between the FD and control groups. The relationship between dyspeptic symptoms and gastric half-emptying time in the FD and control groups were analyzed. Then total symptom scores before and after treatment and gastric half-emptying time were compared among the 3 groups.

RESULTS: The incidence of abdominal pain, epigastric burning sensation, abdominal distension, nausea, belching, and early satiety symptoms in the FD group were significantly higher than in the control group (50.0% vs 20.8%; 37.1% vs 12.5%; 78.6% vs 44.4%; 45.7% vs 22.2%; 52.9% vs 15.3%; 57.1% vs 19.4%; all P < 0.05). The gastric half-emptying times of the proximal end, distal end, and the whole stomach in the FD group were slower than in the control group (93.7 ± 26.2 vs 72.0 ± 14.3; 102.2 ± 26.4 vs 87.5 ± 18.2; 102.1 ± 28.6 vs 78.3 ± 14.1; all P < 0.05). Abdominal distension, belching and early satiety had an effect on distal gastric half-emptying time (P < 0.05). Abdominal distension and abdominal pain had an effect on the gastric half-emptying time of the whole stomach (P < 0.05). All were risk factors (odds ratio > 1). The total symptom score of the 3 groups after treatment was lower than before treatment (P < 0.05). Total symptom scores after treatment in the H. pylori-treatment group and H. pylori-negative group were lower than in the conventional treatment group (5.15 ± 2.27 vs 7.02 ± 3.04, 4.93 ± 3.22 vs 7.02 ± 3.04, All P < 0.05). The gastric half-emptying times of the proximal end, distal end, and the whole stomach in the H. pylori-negative and H. pylori-treatment groups were shorter than in the conventional treatment group (P < 0.05).

CONCLUSION: FD patients have delayed gastric emptying. H. pylori infection treatment helps to improve symptoms of dyspepsia and is a reasonable choice for treatment in clinical practice.