Current understanding of pathogenesis of functional dyspepsia

DNMT1 involved in the analgesic effect of folic acid on gastric hypersensitivity through downregulating ASIC1 in adult offspring rats with prenatal maternal stress

AIMS

Gastric hypersensitivity (GHS) is a characteristic pathogenesis of functional dyspepsia (FD). DNA methyltransferase 1 (DNMT1) and acid-sensing ion channel 1 (ASIC1) are associated with GHS induced by prenatal maternal stress (PMS). The aim of this study was to investigate the mechanism of DNMT1 mediating the analgesic effect of folic acid (FA) on PMS-induced GHS.

METHODS

GHS was quantified by electromyogram recordings. The expression of DNMT1, DNMT3a, DNMT3b, and ASIC1 were detected by western blot, RT-PCR, and double-immunofluorescence. Neuronal excitability and proton-elicited currents of dorsal root ganglion (DRG) neurons were determined by whole-cell patch clamp recordings.

RESULTS

The expression of DNMT1, but not DNMT3a or DNMT3b, was decreased in DRGs of PMS rats. FA alleviated PMS-induced GHS and hyperexcitability of DRG neurons. FA also increased DNMT1 and decreased ASIC1 expression and sensitivity. Intrathecal injection of DNMT1 inhibitor DC-517 attenuated the effect of FA on GHS alleviation and ASIC1 downregulation. Overexpression of DNMT1 with lentivirus not only rescued ASIC1 upregulation and hypersensitivity, but also alleviated GHS and hyperexcitability of DRG neurons induced by PMS.

CONCLUSIONS

These results indicate that increased DNMT1 contributes to the analgesic effect of FA on PMS-induced GHS by reducing ASIC1 expression and sensitivity.

Economic living standard and abdominal pain mediate the association between functional gastrointestinal disorders and depression or anxiety

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are common and cause significant morbidity. Psychiatric comorbidities associated with FGIDs include anxiety and depression. However, little is understood about the factors that modulate this association. The aim of this study was to examine the association between FGIDs and depression and anxiety, and to determine the covariates influencing this association in a New Zealand cohort.

METHODS

The Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT) study is an observational case-control study that recruited FGID cases and healthy controls between 2016 and 2018. In addition to the collection of a wide range of biological samples, participants completed questionnaires concerning socioeconomic status, physical activity, smoking, alcohol intake, anxiety, and depression (the latter two measured using the Hospital Anxiety and Depression Score [HADS]). A multivariate analysis was performed using the significant covariates from the univariate analyses to test whether their effect was independently significant on anxiety and depression.

KEY RESULTS

A total of 315 participants (57 with diarrhea-predominant IBS (IBS-D), 30 with constipation-predominant IBS (IBS-C), 41 with mixed-IBS (IBS-M), 16 with functional diarrhea (FD), 42 with functional constipation (FC), and 129 controls); mean age 53 years (range 18-70 years), 221 (70%) female) completed the questionnaires. Anxiety (odds ratio [OR] 2.85 [95% confidence interval [CI] 1.64-4.94, p < 0.01) and depression (OR 3.40 [95% CI 1.35-8.55, p = 0.01]) were strongly associated with FGID cases versus controls. Lower economic living status (p < 0.01) was an independent covariate associated with depression, while lower economic living status (p < 0.005) and abdominal pain (p = 0.005) were both independently associated with anxiety.

CONCLUSIONS & INFERENCES

In addition to the established associations between FGIDs and anxiety and depression, we have shown that the economic standard of living, pain, and IBS phenotype are significant independent covariates. This study demonstrates the range of lifestyle and demographic factors that modulate morbidity associated with FGIDs and may provide targets for intervention.

Evidence-based clinical practice guidelines for functional dyspepsia 2021

BACKGROUND

Functional dyspepsia (FD) is a disorder that presents with chronic dyspepsia, which is not only very common but also highly affects quality of life of the patients. In Japan, FD became a disease name for national insurance in 2013, and has been gradually recognized, though still not satisfactory. Following the revision policy of Japanese Society of Gastroenterology (JSGE), the first version of FD guideline was revised this time.

METHOD

Like previously, the guideline was created by the GRADE (grading of recommendations assessment, development and evaluation) system, but this time, the questions were classified to background questions (BQs, 24 already clarified issues), future research questions (FRQs, 9 issues cannot be addressed with insufficient evidence), and 7 clinical questions that are mainly associated with treatment.

RESULTS AND CONCLUSION

These revised guidelines have two major features. The first is the new position of endoscopy in the flow of FD diagnosis. While endoscopy was required to all cases for diagnosis of FD, the revised guidelines specify the necessity of endoscopy only in cases where organic disease is suspected. The second feature is that the drug treatment options have been changed to reflect the latest evidence. The first-line treatment includes gastric acid-secretion inhibitors, acetylcholinesterase (AChE) inhibitors (acotiamide, a prokinetic agent), and Japanese herbal medicine (rikkunshito). The second-line treatment includes anxiolytics /antidepressant, prokinetics other than acotiamide (dopamine receptor antagonists, 5-HT4 receptor agonists), and Japanese herbal medicines other than rikkunshito. The patients not responding to these treatment regimens are regarded as refractory FD.

Epigenetic upregulation of acid-sensing ion channel 1 contributes to gastric hypersensitivity in adult offspring rats with prenatal maternal stress

Functional dyspepsia is a common functional gastrointestinal disorder. Gastric hypersensitivity (GHS) is a hallmark of this disorder, but the cellular mechanisms remain largely unknown. Stressors during gestational period could have effects on the offspring's tissue structure and function, which may predispose to gastrointestinal diseases. The aim of this study was to test whether prenatal maternal stress (PMS) induces GHS and to investigate role of acid-sensing ion channel (ASIC)/nuclear factor-κB (NF-κB) signaling by examining Asic1 methylation status in adult offspring rats. Gastric hypersensitivity in response to gastric distension was examined by electromyography recordings. Changes in neuronal excitability were determined by whole-cell patch-clamp recording techniques. Demethylation of CpG islands of Asic1 was determined by methylation-specific PCR and bisulfite sequencing assay. Prenatal maternal stress produced GHS in adult offspring rats. Treatment with amiloride, an inhibitor of ASICs, significantly attenuated GHS and reversed hyperexcitability of gastric-specific dorsal root ganglion (DRG) neurons labeled by the dye DiI. Expression of ASIC1 and NF-κBp65 was markedly enhanced in T7 to T10 DRGs. Furthermore, PMS led to a significant demethylation of CpG islands in the Asic1 promoter. A chromatin immunoprecipitation assay showed that PMS also enhanced the ability of NF-κBp65 to bind the promoter of Asic1 gene. Blockade of NF-κB using lentiviral-p65shRNA reversed upregulation of ASIC1 expression, GHS, and the hyperexcitability of DRG neurons. These data suggest that upregulation of ASIC1 expression is attributed to Asic1 promoter DNA demethylation and NF-κB activation, and that the enhanced interaction of the Asic1 and NF-κBp65 contributes to GHS induced by PMS.

Sini-San Regulates the NO-cGMP-PKG Pathway in the Spinal Dorsal Horn in a Modified Rat Model of Functional Dyspepsia

The present study investigated the effect of Chinese medicine Sini-San (SNS) on visceral hypersensitivity in a rat model of functional dyspepsia (FD), and it explored related underlying mechanisms. The rat model of FD was developed by combining neonatal iodoacetamide (IA) treatment and adult tail-clamping. After SNS treatment, the behavior and electromyographic testing were performed to evaluate the visceromotor responses of rats to gastric distention. Immunofluorescence was used to detect the distribution of iNOS-positive cells in the spinal dorsal horn, while the real-time quantitative PCR and western blot were used for detection of the gene expression of c-fos, iNOS, and GABAb and protein levels of iNOS and GABAb in the spinal dorsal horn, respectively. The protein concentration of cGMP and PKG proteins in the spinal dorsal horn were quantified by enzyme-linked immunosorbent assay. In this study, SNS treatment significantly reduced the behavioral score and electromyographic response to graded intragastric distension pressure. The middle-dose of SNS treatment significantly reduced the distribution of iNOS-positive cells in the spinal dorsal horn of FD model rats. The gene expression of c-fos, iNOS, and GABAb and the protein contents of iNOS, GABAb, cGMP, and PKG in the spinal dorsal horn of FD model rats were restored to a normal level by middle-dose of SNS treatment. Our results suggest that Sini-San may alleviate the visceral hypersensitivity in FD model rats via regulation of the NO/cGMP/PKG pathway in the spinal dorsal horn.

Association between Functional Dyspepsia and Gastric Depressive Erosions in Japanese Subjects

Objective The association between functional dyspepsia (FD) and endoscopic findings has not been fully elucidated. Helicobacter pylori infection is considered a key factor in the pathophysiology of FD. The Kyoto Classification of Gastritis (KCG) was proposed in 2014 to evaluate endoscopic findings based on the H. pylori status. We investigated the endoscopic findings associated with FD according to the KCG. Methods This cross-sectional study included subjects who underwent esophagogastroduodenoscopy during a medical health check-up. We compared the endoscopic findings between subjects with FD and healthy controls (HCs) according to the KCG. Results A total of 456 subjects were analyzed. Among them, the detection rate of FD was 5.5% (25/456 persons). In a univariate analysis of the endoscopic findings, a significantly lower proportion of subjects with FD had gastric red streak in comparison to HCs (0% vs. 18.6%, respectively; p=0.0124). Subjects with FD were more likely to have gastric depressive erosion (20.0% vs. 7.9%; p=0.0522). A higher proportion of the erosion-positive subjects had FD in comparison to erosion-negative subjects (12.8% vs. 4.8%). There were no significant differences in the other endoscopic findings, including gastric atrophy, intestinal metaplasia, enlarged fold, nodularity, and diffuse redness. A multivariate analysis revealed that gastric depressive erosion was significantly and independently associated with FD (odds ratio, 2.92; 95% confidence interval, 1.03-8.26; p=0.0436). In contrast, gastric red streak was not associated with FD (p=0.989). Conclusion Gastric depressive erosions may be associated with dyspepsia.

[Gender Difference in Functional Gastrointestinal Disorders]

Functional gastrointestinal diseases (FGIDs) are known to be influenced more by a lowering of the quality of life, such as mental health and sleep quality, compared to organic diseases. Genetic, microbiological, molecular biological, and social environmental factors are involved in the pathophysiology of FGIDs. In particular, mental factors, such as depression and anxiety, play a major role in the development of FGIDs. The prevalence of most FGIDs is higher in women. Gender needs to be analyzed in patients with FGIDs because it can have a great influence on the onset of FGIDs. Because there are differences in the treatment response according to gender, further research in the development of therapeutic drugs considering this gender difference will be needed, and ultimately it will be possible to lower the prevalence of FGIDs and improve the quality of life of patients.

Anxiety, depression, and anger in functional gastrointestinal disorders: A Cross-sectional observational study

Previous studies have identified a link between anger and somatization. However, little is known about the associations between anger and the development and progression of Functional Gastrointestinal Disorders (FGID). The study aim was to determine the associations between FGID and anger, anxiety, and depression. Participants in this cross-sectional observational study were 109 consecutive patients aged 18-64 years with FGID at Gastroenterology Clinic of Başkent University Hospital. A control group comprised of 96 individuals with no chronic gastrointestinal disorders recruited via snowball sampling. Sociodemographic and clinical information were obtained and participants completed the Hospital Anxiety and Depression Scale and the State-Trait Anger Expression Inventory-2. FGID participants scored higher than controls on depression, anxiety, state anger, and anger expression-in. When the FGID group was divided into upper and lower gastrointestinal symptom groups, the lower symptom group showed higher anger expression-out scores than the upper symptom group. Anger may contribute to the etiology and development of FGID. This is the first study to demonstrate a significant psychological difference between individuals with lower and upper FGID. Interdisciplinary collaboration with gastroenterologists and psychiatrists could strengthen FGID evaluation and may improve treatment compliance.

Helicobacter pylori eradication: influence of interleukin-1beta -31 C/T polymorphism

Aim

To analyze the influence of the –31 C/T polymorphism of the interleukin-1β gene on Helicobacter pylori eradication therapy success in patients with functional dyspepsia.

Methods

Functional dyspepsia was diagnosed according to the Rome III criteria. All patients underwent upper gastrointestinal endoscopy, and gastric biopsies were obtained at screening and 12 months after randomization (last follow-up visit). Urease test and histological examination were performed to define the H. pylori status. Patients received twice-daily amoxicillin, clarithromycin and omeprazole for 10 days. Genotyping of the interleukin-1beta –31 C/T polymorphism (rs1143627) was performed using polymerase chain reaction-restriction fragment length polymorphism.

Results

One hundred forty-nine patients received treatment with triple therapy for H. pylori eradication. Only one patient was lost to follow-up, and adherence to study medication was 94.6%. A total of 148 patients (mean age 46.08 ± 12.24 years; 81.8% women) were evaluated for the influence of the interleukin-1beta –31 C/T polymorphism on the outcome of H. pylori eradication therapy. After treatment, bacteria were eradicated in 87% of patients (129/148). Genotype frequencies of the polymorphism were as follows: CC, 38/148 (25.7%); CT, 71/148 (47.9%); and TT, 39/148 (26.4%). Successful eradication rate was 78.9%, 94.4% and 82.1% for the CC, CT and TT genotypes, respectively. The CT genotype was significantly associated with successful H. pylori eradication (p = 0.039).

Conclusion

This study suggests that the CT genotype of the interleukin-1beta –31 C/T polymorphism plays a role in the successful eradication of H. pylori among patients with functional dyspepsia.

A Randomized, Double-Blind, Multicenter, Placebo-Controlled Trial of Qi-Zhi-Wei-Tong Granules on Postprandial Distress Syndrome-Predominant Functional Dyspepsia

Background:

Functional dyspepsia (FD) is a common upper gastrointestinal disorder worldwide, but the current treatments for FD are still unsatisfactory. The aims of this study were to investigate the efficacy and safety of Qi-Zhi-Wei-Tong granules in patients with postprandial distress syndrome (PDS)-predominant FD.

Methods:

The study was conducted as a randomized, double-blinded, multicenter, placebo-controlled design in 197 patients with PDS. All participants received placebo treatment for 1 week. Patients whose total symptom score decreased by <50% after the placebo treatment were recruited into the 4-week treatment period, in which they were randomly assigned to be treated with either Qi-Zhi-Wei-Tong granules or placebo. The patients were then followed for 2 weeks without any treatment. Dyspeptic symptoms were scored at weeks 2 and 4 during the random treatment period and 2 weeks after the treatment. Anxiety and depression symptoms were also scored and compared.

Results:

(1) The total effective rates in the Qi-Zhi-Wei-Tong granules group at weeks 2 and 4 during the random treatment period and 2 weeks after treatment were all significantly higher than those in the placebo group (38.82% vs. 8.75%, P < 0.001; 69.14% vs. 16.25%, P < 0.001; 77.65% vs. 21.25%, P < 0.001). (2) The total dyspeptic symptoms scores in the Qi-Zhi-Wei-Tong granules group at weeks 2 and 4 and 2 weeks after treatment were significantly lower than those in the placebo group. (3) The severity and frequency of each dyspeptic symptom at weeks 2 and 4 and the follow-up period were all significantly lower than those in the placebo group. (4) The anxiety scores in the Qi-Zhi-Wei-Tong granules group were significantly lower than those in the placebo group. (5) Qi-Zhi-Wei-Tong granules did not have more adverse effects than the placebo.

Conclusion:

Qi-Zhi-Wei-Tong granules offer significant symptomatic improvement in PDS with no more adverse effects than placebo.

Trial Registration:

https://clinicaltrials.gov/, NCT02460601.

Chronic Diffuse Pain and Functional Gastrointestinal Disorders After Traumatic Stress: Pathophysiology Through a Polyvagal Perspective

Chronic diffuse pain disorders, such as fibromyalgia, and functional gastrointestinal disorders (FGIDs), such as irritable bowel syndrome, place substantial burden on those affected and on the medical system. Despite their sizable impact, their pathophysiology is poorly understood. In contrast to an approach that focuses on the correlation between heart rate variability (HRV) and a specific organ or symptom, we propose that a bio-evolutionary threat-related autonomic response—as outlined in the Polyvagal Theory—may serve as a plausible explanation of how HRV, particularly respiratory sinus arrhythmia (RSA), would index the pathophysiology of these disorders. Evidence comes from: (1) the well-documented atypical autonomic regulation of the heart common to fibromyalgia and irritable bowel syndrome reflected in dampened RSA, (2) the neural architecture that integrates the heart, pain pathways, and the gastrointestinal tract, (3) the common physical co-morbidities shared by chronic diffuse pain and FGIDs, many of which are functionally regulated by the autonomic nervous system, (4) the elevated risk of chronic diffuse pain and FGIDs following traumatic stress or abuse, (5) and the elevated risk of chronic diffuse pain and FGIDs in individuals with anxiety and panic disorders. This novel conceptualization points to a pathogenesis rooted in changes to brain-body autonomic feedback loops in response to evolutionarily-salient threat cues, providing an integrated biopsychosocial model of chronic diffuse pain and FGIDs and suggesting new, non-pharmacological treatment strategies.

Regional Brain Activity During Rest and Gastric Water Load in Subtypes of Functional Dyspepsia: A Preliminary Brain Functional Magnetic Resonance Imaging Study

Background/Aims

Functional dyspepsia (FD) remains a great clinical challenge since the FD subtypes, defined by Rome III classification, still have heterogeneous pathogenesis. Previous studies have shown notable differences in visceral sensation processing in the CNS in FD compared to healthy subjects (HS). However, the role of CNS in the pathogenesis of each FD subtype has not been recognized.

Methods

Twenty-eight FD patients, including 10 epigastric pain syndrome (EPS), 9 postprandial distress syndrome (PDS), and 9 mixed-type, and 10 HS, were enrolled. All subjects underwent a proximal gastric perfusion water load test and the regional brain activities during resting state and water load test were investigated by functional magnetic resonance imaging.

Results

For regional brain activities during the resting state and water load test, each FD subtype was significantly different from HS (P < 0.05). Focusing on EPS and PDS, the regional brain activities of EPS were stronger than PDS in the left paracentral lobule, right inferior frontal gyrus pars opercularis, postcentral gyrus, precuneus, insula, parahippocampal gyrus, caudate nucleus, and bilateral cingulate cortices at the resting state (P < 0.05), and stronger than PDS in the left inferior temporal and fusiform gyri during the water load test (P < 0.05).

Conclusions

Compared to HS, FD subtypes had different regional brain activities at rest and during water load test, whereby the differences displayed distinct manifestations for each subtype. Compared to PDS, EPS presented more significant differences from HS at rest, suggesting that the abnormality of central visceral pain processing could be one of the main pathogenesis mechanisms for EPS.

Lanthanum Deposition in the Stomach in the Absence of Helicobacter pylori Infection

In this case report, we describe two patients who showed a diffusely whitish mucosa in the posterior wall and the lesser curvature of the gastric body. The patients were serologically- and histopathologically-negative for Helicobacter pylori. Random biopsy specimens from the stomach revealed no regenerative changes, intestinal metaplasia, and/or foveolar hyperplasia in either of the patients. Although lanthanum deposition in the gastric mucosa has been reported to occur in close association with H. pylori-associated gastritis, our patients tested negative for H. pylori. These cases suggest that lanthanum deposition presents as whitish lesions in the gastric body in H. pylori-negative patients.

Investigation of autophagy and differentiation of myenteric interstitial cells of Cajal in the pathogenesis of gastric motility disorders in rats with functional dyspepsia

Interstitial cells of Cajal (ICC), especially myenteric interstitial cells of Cajal (ICC-MY), are key to gastrointestinal motility. However, their role in the pathogenesis of functional dyspepsia (FD) is unclear. Therefore, autophagy and differentiation of ICC-MY were investigated to elucidate the pathogenesis of gastric motility disorder in FD. FD model was induced by chronic stress via tail clamping in rats, which was assessed by the vital signs of rats, gastric emptying rate result, and histology. The ultrastructure of ICC-MY was examined using transmission electron microscope. In ICC-MY, changes in autophagic biomarkers (Beclin1 and LC3B) and differentiation biomarkers (c-kit and SCF) were evaluated with in situ hybridization, quantitative real time PCR, immunofluorescence, and Western blot, respectively. The FD model was successfully induced in rats, as evidenced by the abnormal vital signs (such as loss of appetite, liquid excreta, less activity, and slower weight gain), the decrease in gastric emptying rates, and little pathological change in gastric antrum tissue. Compared with the control group, FD caused increased organelle denaturation or reduction and increase in vacuolization. FD also promoted generation of autophagosomes in ICC-MY. Moreover, increased the expression of Beclin1 and LC3B, but decreased expression of c-kit and SCF. Excessive autophagy and abnormal differentiation of ICC-MY may contribute to the pathogenesis of gastric motility disorder in FD.

Potential rat model of anxiety-like gastric hypersensitivity induced by sequential stress

AIM

To establish a rat model of anxiety-like gastric hypersensitivity (GHS) of functional dyspepsia (FD) induced by novel sequential stress.

METHODS

Animal pups were divided into two groups from postnatal day 2: controls and the sequential-stress-treated. The sequential-stress-treated group received maternal separation and acute gastric irritation early in life and restraint stress in adulthood; controls were reared undisturbed with their mothers. Rats in both groups were followed to adulthood (8 wk) at which point the anxiety-like behaviors and visceromotor responses to gastric distention (20-100 mmHg) and gastric emptying were tested. Meanwhile, alterations in several anxiety-related brain-stomach modulators including 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), brain-derived neurotrophic factor (BDNF) and nesfatin-1 in the rat hippocampus, plasma and gastric fundus and the 5-HT1A receptor (5-HT1AR) in the hippocampal CA1 subfield and the mucosa of the gastric fundus were examined.

RESULTS

Sequential-stress-treated rats simultaneously demonstrated anxiety-like behaviors and GHS in dose-dependent manner compared with the control group. Although rats in both groups consumed similar amount of solid food, the rate of gastric emptying was lower in the sequential-stress-treated rats than in the control group. Sequential stress significantly decreased the levels of 5-HT (51.91 ± 1.88 vs 104.21 ± 2.88, P < 0.01), GABA (2.38 ± 0.16 vs 5.01 ± 0.13, P < 0.01) and BDNF (304.40 ± 10.16 vs 698.17 ± 27.91, P < 0.01) in the hippocampus but increased the content of nesfatin-1 (1961.38 ± 56.89 vs 1007.50 ± 33.05, P < 0.01) in the same site; significantly decreased the levels of 5-HT (47.82 ± 2.29 vs 89.45 ± 2.61, P < 0.01) and BDNF (257.05 ± 12.89 vs 536.71 ± 20.73, P < 0.01) in the plasma but increased the content of nesfatin-1 in it (1391.75 ± 42.77 vs 737.88 ± 33.15, P < 0.01); significantly decreased the levels of 5-HT (41.15 ± 1.81 vs 89.17 ± 2.31, P < 0.01) and BDNF (226.49 ± 12.10 vs 551.36 ± 16.47, P < 0.01) in the gastric fundus but increased the content of nesfatin-1 in the same site (1534.75 ± 38.52 vs 819.63 ± 38.04, P < 0.01). The expressions of 5-HT1AR in the hippocampal CA1 subfield and the mucosa of the gastric fundus were down-regulated measured by IHC (Optical Density value: Hippocampus 15253.50 ± 760.35 vs 21149.75 ± 834.13; gastric fundus 15865.25 ± 521.24 vs 23865.75 ± 1868.60; P < 0.05, respectively) and WB (0.38 ± 0.01 vs 0.57 ± 0.03, P < 0.01) (n = 8 in each group).

CONCLUSION

Sequential stress could induce a potential rat model of anxiety-like GHS of FD, which could be used to research the mechanisms of this intractable disease.

The Role of Esophageal Hypersensitivity in Functional Heartburn

Functional heartburn (FH) is defined as a functional esophageal disorder characterized by symptoms of chronic heartburn with no apparent correlation to acid or nonacid reflux. In addition, its symptoms persist despite the lack of organic abnormalities or inflammation, esophageal motility disorders, or metabolic disorders. Although conditions presenting with esophageal symptoms without endoscopic abnormalities were previously categorized as nonerosive reflux disease, such conditions are now classified into 3 categories under Rome IV criteria: nonerosive reflux disease, reflux hypersensitivity, and FH. Although many aspects of FH remain unclear, its onset mechanism is considered to be strongly associated with peripheral or central sensitization, given the fact that its symptoms seem to be unrelated to gastroesophageal reflux. In addition, the cause of such hypersensitivity is an interesting topic in itself, and psychological factors, such as stress followed by increasing esophageal permeability are gaining attention as factors that can potentially influence this condition. There is a great unmet clinical need for therapeutic drugs that can be used to treat FH, and the development of novel drugs, diagnostic tests and biomarkers is eagerly awaited.

The Esophageal and Gastric Microbiome in Health and Disease

The esophagus and stomach are host to their own population of bacteria, which differs in health and disease. Helicobacter pylori uniquely colonizes only gastric mucosa, but an increasing number of bacteria is now isolated from the gastric juice and gastric mucosa, including Lactobacillus. The presence of H pylori alters populations of other gastric bacteria with a marked reduction in diversity. Alterations in intragastric acidity may be the cause or the consequence of changes in the microbial populations of the stomach. Esophageal inflammation is associated with an altered microbiota in gastroesophageal reflux disease, Barrett's esophagus, eosinophilic esophagitis, and cancer.

Gastric Activity and Gut Peptides in Patients With Functional Dyspepsia: Postprandial Distress Syndrome Versus Epigastric Pain Syndrome

GOALS

The goals of the study were to investigate in both postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) the gastric electrical activity and the gastric emptying (GE) time together with the circulating concentrations of motilin, somatostatin, corticotrophin-releasing factor, and neurotensin, and to establish whether the genetic variability in the neurotensin system genes differs between these 2 categories of functional dyspepsia (FD).

BACKGROUND

The current FD classification is based on symptoms and it has been proven not to be completely satisfying because of a high degree of symptom overlap between subgroups.

STUDY

Gastric electrical activity was evaluated by cutaneous electrogastrography: the GE time by C-octanoic acid breast test. Circulating concentrations of gut peptides were measured by a radioimmunoassay. NTS 479 A/G and NTSR1 rs6090453 SNPs were evaluated by PCR and endonuclease digestion.

RESULTS

Fifty-four FD patients (50 female/4 male) were studied. Using a symptom questionnaire, 42 patients were classified as PDS and 12 as EPS, although an overlap between the symptom profiles of the 2 subgroups was recorded. The electrogastrographic parameters (the postprandial instability coefficient of dominant frequency, the dominant power, and the power ratio) were significantly different between the subgroups, whereas the GE time did not differ significantly. In addition, EPS was characterized by a different gut peptide profile compared with PDS. Finally, neurotensin polymorphism was shown to be associated with neurotensin levels. This evidence deserves further studies in consideration of an analgesic role of neurotensin.

CONCLUSIONS

Analysis of gut peptide profiles could represent an interesting tool to enhance FD diagnosis and overcome limitations due to a distinction based solely on symptoms.

Dyspepsia and constipation in patients with schizophrenia spectrum disorders

Constipation and dyspepsia are disturbing gastrointestinal symptoms that are often ignored in research on physical comorbidities of schizophrenia. The aim was to assess dyspepsia and constipation in a sample of outpatients with schizophrenia spectrum psychoses. A general practitioner performed a thorough physical health check for 275 outpatients and diagnosed constipation and dyspepsia. This study assessed the possible contribution of several sociodemographic, lifestyle, and clinical variables to constipation and dyspepsia using logistic regression analysis. This study also assessed whether these symptoms were associated with abnormal laboratory findings. The prevalence of constipation was 31.3%, and of dyspepsia 23.6%. Paracetamol (OR =3.07, 95% CI =1.34-7.02) and clozapine use (OR =5.48, 95% CI =2.75-10.90), older age (OR =1.04, 95% CI =1.01-1.06), and living in sheltered housing (OR =2.49, 95% CI =1.16-5.33) were risk factors for constipation. For dyspepsia the risk factors were female sex (OR =2.10, 95% CI =1.15-3.83), non-steroidal anti-inflammatory drugs (OR =2.47, 95% CI =1.13-5.39), and diabetes medication (OR =2.42, 95% CI =1.12-5.25). Patients with dyspepsia had lower haemoglobin and haematocrit and higher glucose values than those without dyspepsia. Patients with constipation had lower thrombocyte values than patients without constipation. However, these findings were explained by factors pre-disposing to constipation and dyspepsia. Clozapine use markedly increases the risk of constipation and may lead to life-threatening complications. In addition, analgesics and diabetes medication were related to gastrointestinal symptoms. These medications and their association to gastrointestinal symptoms should be kept in mind when treating patients with schizophrenia.

LACK OF ASSOCIATION BETWEEN HELICOBACTER PYLORI'S VIRULENCE AND INCREASED SERUM C-REACTIVE PROTEIN LEVELS IN FUNCTIONAL DYSPEPTIC PATIENTS

ABSTRACT Background Recently, a great variety of studies aimed to investigate and even suggestHelicobacter pylori as an important key factor in gastrointestinal and non-gastrointestinal events development. The well-established relationship between bacterial virulence and increased risk for peptic ulcer or gastric carcinoma is not so clear when comparing inflammation markers alterations, such C-reactive protein, with the pathogen. Objective The objective of this study was to evaluate the presence of H. pylori, bacterial virulence and C-reactive protein serum levels in individuals diagnosed with functional dyspepsia. Methods Were prospectively included in this study 489 dyspeptic individuals. They fulfill Rome III clinical criteria for the diagnosis of functional dyspepsia with no organic disease at endoscopy. The bacterial infection was established by histology and urease rapid test. The levels of serum C-reactive protein were obtained by immunonefelometry and CagA status ofH. pylori positive individuals was determined through an imunoenzimatic assay. Results Prevalence rate of H. pylori was 66.3% and virulence factor CagA was detected in nearly 43% of positive samples. In addition, it has been noticed an association between Ilex paraguariensis(yerba maté) consumption and pathogen's prevalence. An important effect of bacterial infection on inflammation was only observed in gastric epithelium. Conclusion No systemic response to the pathogen, measured through C-reactive protein levels, was observed, regardless of CagA status. Otherwise, the intake of yerba maté should be considered as a cultural factor possibly related toH. pylori's transmission.

Dysbiotic infection in the stomach

Microbiota in human alimentary tract plays important roles for homeostatic maintenance of the body. Compositional difference of gut microbiota is tightly associated with susceptibility of many diseases, including inflammatory diseases, obesity, diabetes mellitus, cancer, and atherosclerosis. “Dysbiosis” refers to a state of imbalance among the colonies of microorganisms within the body, which brings abnormal increase of specific minor components and decrease in the normally dominant species. Since stomach secrets strong acid for its digestive role, this organ has long been thought a sterile organ. However, the discovery of Helicobacter pylori (H. pylori) has changed the concept. This bacterium has proven to cause gastritis, peptic ulcer, and gastric cancer. However, recent cross-sectional studies revealed that H. pylori carriers had a decreased risk of developing immunological diseases, such as asthma. H. pylori coinfection also suppresses inflammatory bowel diseases. This review describes human gastric microbiota by discussing its mutual interaction and pathogenic enrollment. Gastric “dysbiosis” may affect host inflammatory response and play important role for gastric pathogenesis. We will topically discuss enrollment of dysbiosis for genesis of gastric cancer as well as for disruption of immunological homeostasis affecting oncogenic resistance.

Comparing the Areas of Interest in the Field of Functional Gastrointestinal Disorder and Neurogastroenterology and Motility Between the East and the West

There is a paucity of studies that compare the differences in published articles submitted from the East and the West in the area of neurogastroenterology and motility (NM). To compare the article topics from the East and the West which have been published, 5 Western (Gastroenterology, Gut, American Journal of Gastroenterology, American Journal of Physiology-Gastrointestinal and Liver Physiology, and Neurogastroenterology and Motility) and 3 Eastern gastrointestinal journals (Journal of Gastroenterology, Journal of Gastroenterology and Hepatology, and Journal of Neurogastroenterology and Motility) were selected based on the impact factor. Published papers were classified into 12 categories and 60 subcategories. The titles and abstracts of review articles, original articles, and meta-analyses from these journals were reviewed for the last 2 years (2013–2014). In case of Journal of Neurogastroenterology and Motility which is published quarterly, this search was performed for 5 years (2010–2014). Of the total 2656 reviewed articles, 842 (260 from the East and 582 from the West) were classified into the category of NM. The most frequently published papers from the Western researchers were categorized as brain-gut interaction, visceral hypersensitivity, and irritable bowel syndrome, whereas those from the Eastern researchers were categorized as gastroesophageal reflux disease, functional dyspepsia, and irritable bowel syndrome. This difference between the East and the West is not just due to the journal itself, but it also depends on the author’s affiliation and their ability to perform high quality research in the area of the NM. These data provide evidence for the research trend and give valuable information to the researchers for determining subjects for the study and for selecting proper journals for publishing their studies.

Evidence for neuronal and structural changes in submucous ganglia of patients with functional dyspepsia

OBJECTIVES

An intact and well-functioning enteric nervous system is necessary to efficiently organize gut function. Functional gastrointestinal disorders are pathological entities in which gut function is impaired without a clearly established pathophysiology. On the basis of the relative ease with which intestinal biopsies can be obtained, and taking advantage of a recently developed optical recording technique, we evaluated whether functional neuronal defects exist in enteric nerves of patients with functional dyspepsia (FD).

METHODS

The submucous plexus isolated from duodenal biopsies taken from FD patients and control subjects was used to functionally and morphologically examine nerves and ganglionic architecture (neurons and glial cells). In light of previous studies reporting eosinophil and mast cell infiltration in the gut mucosa of FD patients, we also examined whether these cells infiltrated the submucous plexus and whether this correlated with neuronal activity and specific clinical symptoms.

RESULTS

We demonstrate that neuronal functioning is impaired in the submucous plexus of FD patients, as shown by decreased calcium responses to depolarization and electrical stimulation. Glial (S100) and neuronal (HuCD) markers show signs of gliosis, altered ganglionic architecture, and neuronal abnormalities in the submucous plexus of FD patients. We found that eosinophils and mast cells infiltrated the submucous layer of FD patients to a much larger extent than in controls. A significant correlation was found between the number of these cells and the calcium transient amplitudes measured in submucous ganglia.

CONCLUSIONS

We provide the first direct evidence that FD is characterized by functional and structural abnormalities within the submucous ganglion plexus, which may be of future predictive and diagnostic value in the treatment of FD patients.

No increase in prevalence of somatization in functional vs organic dyspepsia: a cross-sectional survey

BACKGROUND

Psychological factors are associated with functional gastrointestinal (GI) disorders. Literature suggests that somatization is associated with functional dyspepsia (FD). However, the relationship between organic dyspepsia (OD), FD, and FD subtypes and somatization is poorly described. We aimed to examine this issue in a cross-sectional study of secondary care patients.

METHODS

Demographic and GI symptom data were collected from 4224 adult patients via the Rome III questionnaire. Somatization data were collected using the patient health questionnaire-12. Mean somatization score and number of somatic symptoms were compared between patients with organic and FD, and between FD subtypes using analysis of variance. The same comparison was undertaken for the proportion of patients reporting individual somatic symptoms.

KEY RESULTS

Exactly, 783 patients met criteria for dyspepsia, of whom 231 (29.5%) had organic disease following upper GI endoscopy. Mean somatization scores and number of somatic symptoms were no higher in functional vs OD (p = 0.23; p = 0.19). In addition, while the prevalence of somatization in FD was relatively high, there was no difference in severity of somatization in FD subgroups.

CONCLUSIONS & INFERENCES

Somatization is associated with functional and OD to the same degree. Overall severity of somatization did not appear to vary according to FD subtype.

Continuous consumption of fermented milk containing Bifidobacterium bifidum YIT 10347 improves gastrointestinal and psychological symptoms in patients with functional gastrointestinal disorders

The aim of this study was to investigate whether consumption of probiotic fermented milk containing Bifidobacterium bifidum YIT 10347 improves symptoms in patients with functional gastrointestinal disorders (FGID). Thirty-seven FGID patients (18 male, 19 female) aged 12–80 years (mean ± SD, 52.6 ± 17.5 years) whose condition had not improved despite being seen at several medical institutions consumed 100 mL/day of B. bifidum YIT 10347 fermented milk for 4 weeks. Symptoms were evaluated after the enrollment period (BL: baseline), sample consumption period (CP) and 4 weeks after the CP (FP: follow-up period). Gastrointestinal symptoms were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS) and the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG); psychological symptoms were evaluated using the Profile of Mood States (POMS) short form. Concentrations of salivary stress markers and the oxidative stress marker urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) were measured. GSRS subscale scores for abdominal pain, diarrhea, and constipation significantly improved relative to BL after consumption of the fermented milk, as did FSSG subscale scores for symptoms of acid-related dyspepsia. Some subjective psychological symptoms improved. POMS scores significantly improved, and “Anger-Hostility” subscale scores significantly decreased after the consumption period, while “Vigor” subscale scores marginally increased during the consumption period. The concentrations of urinary 8-OHdG and the stress marker salivary cortisol were significantly lower at CP but returned to baseline levels at FP. Continuous consumption of B. bifidum YIT 10347 fermented milk is expected to improve gastrointestinal symptoms and reduce psychological stress in FGID patients.

Offshore training in navy personnel is associated with uninvestigated dyspepsia

To investigate the known and new factors associated with uninvestigated dyspepsia (UD), we surveyed 8600 Chinese navy personnel with offshore training shorter than 1 month or longer than 9 months per year. All respondents were required to complete a questionnaire covering demographics, the Chinese version of the Rome III survey, eating habits, life styles, and medical and family history. The response rate was 94.3% (8106/8600) with 4899 respondents qualified for analysis, including 1046 with offshore training and 3853 with onshore training. The prevalence of UD was higher in the offshore group than in the onshore group (12.6% vs. 6.9%, P<0.001), with a general prevalence of 8.1%. The subjects with offshore training were more likely to suffer from UD and postprandial distress syndrome (OR=1.955, 95% CI 1.568-2.439, P<0.001 and OR=1.789, 95% CI 1.403-2.303, P<0.001, respectively). The multivariate logistic regression analysis showed UD was associated with offshore training (OR=1.580, 95% CI 1.179-2.118, P=0.002), family history (OR=1.765, 95% CI 1.186-2.626, P=0.005) and smoking (OR=1.270, 95% CI 1.084-1.488, P=0.003), but not with alcohol drinking. The association between dysentery history and UD was undetermined/borderline (P=0.056-0.069). In conclusion, we identified offshore training as a new factor associated with UD, and also confirmed 2 known associated factors, family history and smoking.

Treatment of functional dyspepsia and gastroparesis

OPINION STATEMENT

Functional dyspepsia (FD) and gastroparesis (GP) are the two most prevalent gastric neuromuscular disorders. These disorders are frequently confused, have more similarities than differences, and can be thought of as two ends of a continuous spectrum of gastric neuromuscular disorders (Fig. 1). FD is currently defined by the Rome III criteria; it is now subdivided into a pain-predominant subtype (epigastric pain syndrome) and a meal-associated subtype (post-prandial distress syndrome). GP is defined by symptoms in conjunction with delayed gastric emptying in the absence of mechanical obstruction. Symptoms for both FD and GP are similar and include epigastric pain or discomfort, early satiety, bloating, and post-prandial nausea. Vomiting can occur with either diagnosis; it is typically more common in GP. A patient suspected of having either FD or GP should undergo upper endoscopy. In suspected FD, upper endoscopy is required to exclude an alternative organic cause for the patient's symptoms; however, most (70 %) patients with dyspeptic symptoms will have FD rather than an organic disorder. In suspected GP, upper endoscopy is required to rule out a mechanical obstruction. A 4-hour solid-phase gastric emptying scan is recommended to confirm the diagnosis of GP; its utility is unclear in patients with FD, as it may not change treatment. Once the diagnosis of FD or GP is made, treatment should focus on the predominant symptom. This is especially true in patients with GP, as accelerating gastric emptying with the use of prokinetics may not necessarily translate into an improvement in symptoms. Unfortunately, no medication is currently approved for the treatment of FD and, thus, technically, all treatment options remain off-label, including medications for visceral pain (e.g., tricyclic antidepressants) and nausea. This review focuses on treatment options for FD and GP with an emphasis on new advances in the field over the last several years.

Relationship between functional dyspepsia and Helicobacter pylori infection

AIM: To investigate the correlation between functional dyspepsia (FD) and Helicobacter pylori (H. pylori) infection.

METHODS: A total of 1570 FD patients with H. pylori infection were recruited. Four hundred FD patients with H. pylori infection who did not have abnormal social psychological factors were divided randomly into either a treatment group or a control group. The treatment group was further divided into an eradication success group or an eradication failure group by H. pylori eradication status one month after the eradication therapy. Twelve months after treatment, improvement of symptoms and the average cost of rescue medication were analyzed and compared between groups.

RESULTS: In the H. pylori eradication success group, the symptoms improved more significantly compared with the H. pylori eradication failure group and control group one month after treatment, and the proportion of patients with symptomatic improvement ≥ 50% in the H. pylori eradication success group was significantly higher than those in the other two groups 12 mo after treatment. The average cost of rescue medication in the H. pylori eradication success group was significantly less than that in the control group and the H. pylori eradication failure group one month before the end of follow-up.

CONCLUSION: H. pylori has a certain relevance to FD. H. pylori eradication in H. pylori positive FD patients who are not associated with abnormal social psychological factors can achieve good treatment effects.

Radionuclide gastric emptying scintigraphy in patients with functional dyspepsia

AIM: To assess the use of gastric emptying scintigraphy with solid test meal in patients with functional dyspepsia (FD) and normal subjects.

METHODS: Forty-two patients with FD and 30 normal subjects underwent gastric emptying scintigraphy with 99mTc-DTPA labeling egg solid meal. The standard curve of gastric emptying was plotted to figure out the half-time of gastric emptying and emptying rate at 60 and 120 min by three different methods: method 1 with the radioactivity of the anterior view, method 2 with the mean value of and method 3 with the geometric mean of the radioactivity of the anterior and pastier views as the y-axis of the standard curve of gastric emptying, respectively. The differences in half-times and gastric emptying rates at 60 and 120 min figured out by the three different methods were compared between patients with FD and normal subjects.

RESULTS: One-way analysis of variance was performed to compare the differences in half-times. The half-time figured out by method 1 did not differ significantly from that by method 2 (P = 0.808, P = 0.243, P > 0.05), but the half-time figured out by method 3 differed significantly from those by methods 1 and 2 (1 vs 3: P = 0.007, P = 0.000; 2 vs 3: P = 0.035, P = 0.023; P < 0.05 for all). The half-time and gastric emptying rates at 60 and 120 min differed significantly between FD patients and normal subjects (P = 0.000). Method 1 figured out 80.9%, method 2 figured out 71.4% and method 3 figured out 90.5% of FD patients had longer half-time than normal subjects.

CONCLUSION: Radionuclide 99mTc-DTPA gastric emptying scintigraphy with solid meal is a simple, accurate, quantitative and physiologic method for measuring gastric motility in FD patients.

Effects of Kampo on functional gastrointestinal disorders

This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigastiric discomfort, but also extra-gastric symptoms, such as general fatigue, when compared with control drugs. The therapeutic effects of rikkunshito were more evident when it was prescribed to patients with “kyosho”, i.e., low energy. Two RCTs suggested the efficacy of keishikashakuyakuto for IBS.

Basic research studies have demonstrated that these Kampo medicines have multiple sites of action to improve subjective symptoms. For example, rikkunshito improves gastric motility dysfunction, including impaired adaptive relaxation and delayed gastric emptying, gastric hypersensitivity, and anorexia via facilitation of ghrelin secretion. It also exhibits anti-stress effects, i.e., it attenuates stress-induced exacerbation of gastric sensation and anorexia, as well as the hypothalamic-pituitary-adrenocortical axis and sympathetic activation. Keishikashakuyakuto exhibited not only an antispasmodic effect on intestinal smooth muscle, but also antidepressant-like effects. Case series suggest that other Kampo prescriptions are also effective for FD and IBS. However, further studies are necessary to evaluate their efficacy.

Real-time gastric motility monitoring using transcutaneous intraluminal impedance measurements (TIIM)

The stomach plays a critical role in digestion, processing ingested food mechanically and breaking it up into particles, which can be effectively and efficiently processed by the intestines. When the motility of the stomach is compromised, digestion is adversely affected. This can lead to a variety of disorders. Current diagnostic techniques for gastric motility disorders are seriously lacking, and are based more on eliminating other possibilities rather than on specific tests. Presently, gastric motility can be assessed by monitoring gastric emptying, food transit, intragastric pressures, etc. The associated tests are usually stationary and of relatively short duration. The present study proposes a new method of measuring gastric motility, utilizing the attenuation of an oscillator-induced electrical signal across the gastric tissue, which is modulated by gastric contractions. The induced high-frequency oscillator signal is generated within the stomach, and is picked up transluminally by cutaneous electrodes positioned on the abdominal area connected to a custom-designed data acquisition instrument. The proposed method was implemented in two different designs: first a transoral catheter was modified to emit the signal inside the stomach; and second, a gastric retentive pill was designed to emit the signal. Both implementations were applied in vivo on two mongrel dogs (25.50 kg and 25.75 kg). Gastric contractions were registered and quantitatively compared to recordings from force transducers sutured onto the serosa of the stomach. Gastric motility indices were calculated for each minute, with transluminal impedance measurements and the measurements from the force transducers showing statistically significant (p < 0.05) Pearson correlation coefficients (0.65 ± 0.08 for the catheter-based design and 0.77 ± 0.03 for the gastric retentive pill design). These results show that transcutaneous intraluminal impedance measurement has the potential with further research and development to become a useful diagnostic technique.

Gastrointestinal symptoms and associated factors in Chinese patients with functional dyspepsia

AIM: To study the evolution of gastrointestinal symptoms and associated factors in Chinese patients with functional dyspepsia (FD).

METHODS: From June 2008 to November 2009, a total of 1049 patients with FD (65.3% female, mean age 42.80 ± 11.64 years) who visited the departments of gastroenterology in Wuhan, Beijing, Shanghai, Guangzhou, and Xi’an, China were referred for this study. All of the patients fulfilled the Rome III criteria for FD. Baseline demographic data, dyspepsia symptoms, anxiety, depression, sleep disorder, and drug treatment were assessed using self-report questionnaires. Patients completed questionnaires at baseline and after 1, 3, 6 and 12 mo follow-up. Comparison of dyspepsia symptoms between baseline and after follow-up was explored using multivariate analysis of variance of repeated measuring. Multiple linear regression was done to examine factors associated with outcome, both longitudinally and horizontally.

RESULTS: Nine hundred and forty-three patients (89.9% of the original population) completed all four follow-ups. The average duration of follow-up was 12.24 ± 0.59 mo. During 1-year follow-up, the mean dyspeptic symptom score (DSS) in FD patients showed a significant gradually reduced trend (P < 0.001), and similar differences were found for all individual symptoms (P < 0.001). Multiple linear regression analysis showed that sex (P < 0.001), anxiety (P = 0.018), sleep disorder at 1-year follow-up (P = 0.019), weight loss (P < 0.001), consulting a physician (P < 0.001), and prokinetic use during 1-year follow-up (P = 0.035) were horizontally associated with DSS at 1-year follow-up. No relationship was found longitudinally between DSS at 1-year follow-up and patient characteristics at baseline.

CONCLUSION: Female sex, anxiety, and sleep disorder, weight loss, consulting a physician and prokinetic use during 1-year follow-up were associated with outcome of FD.

Sonographic evaluation of proximal gastric accommodation in patients with functional dyspepsia

AIM: To assess the value of ultrasonography (US) in evaluation of proximal gastric accommodation disorder in patients with functional dyspepsia (FD).

METHODS: Between April 2011 and March 2012, 45 patients with FD and 27 healthy volunteers were enrolled in this study. Two-dimensional ultrasound (2DUS) and 3-dimensional ultrasound (3DUS) were performed sequentially to measure proximal gastric area (PGA), maximal proximal gastric diameter (MPGD), and proximal gastric volume (PGV). These values were measured separately in the two groups every other 5 min for a duration of 25 min after the beginning of ingestion of a test meal. Air pocket grading was done separately for images of 2DUS and blocks of 3DUS obtained at five scanning time points.

RESULTS: Both PGA and PGV of patients were significantly smaller than healthy controls (P = 0.000 and 0.002, respectively). Comparing the two parameters between the groups at each time point, the differences were also statistically significant (P = 0.000-0.013), except at 10 min for the PGV (P = 0.077). However, no overall difference was found between the groups in the MPGD measurements (P = 0.114), though it was statistically significant at a 20-minute examination point (P = 0.026). A total of 360 sets or blocks of images were obtained for both 2DUS and 3DUS. For the images analyzed by 2DUS, none were excluded because of gastric gas, and 50 (13.9%) and 310 (86.1%) sets were determined as air pockets grades 1 and 2, respectively. For the images analyzed by 3DUS, 23 (6.4%) blocks were excluded from the measurement due to presence of a large fundus air pocket (grade 3); fifty (13.9%) and 287 (79.7%) blocks were also graded as 1 and 2, respectively.

CONCLUSION: Measurement of both PGA and PGV by 2DUS and 3DUS could be useful for assessment of the proximal gastric accommodation.

Whole-brain functional connectivity identification of functional dyspepsia

Recent neuroimaging studies have shown local brain aberrations in functional dyspepsia (FD) patients, yet little attention has been paid to the whole-brain resting-state functional network abnormalities. The purpose of this study was to investigate whether FD disrupts the patterns of whole-brain networks and the abnormal functional connectivity could reflect the severity of the disease. The dysfunctional interactions between brain regions at rest were investigated in FD patients as compared with 40 age- and gender- matched healthy controls. Multivariate pattern analysis was used to evaluate the discriminative power of our results for classifying patients from controls. In our findings, the abnormal brain functional connections were mainly situated within or across the limbic/paralimbic system, the prefrontal cortex, the tempo-parietal areas and the visual cortex. About 96% of the subjects among the original dataset were correctly classified by a leave one-out cross-validation approach, and 88% accuracy was also validated in a replication dataset. The classification features were significantly associated with the patients' dyspepsia symptoms, the self-rating depression scale and self-rating anxiety scale, but it was not correlated with duration of FD patients (p>0.05). Our results may indicate the effectiveness of the altered brain functional connections reflecting the disease pathophysiology underling FD. These dysfunctional connections may be the epiphenomena or causative agents of FD, which may be affected by clinical severity and its related emotional dimension of the disease rather than the clinical course.

Functional Dyspepsia in Review: Pathophysiology and Challenges in the Diagnosis and Management due to Coexisting Gastroesophageal Reflux Disease and Irritable Bowel Syndrome

Functional dyspepsia is a common disorder which imposes significant diagnostic and treatment challenges for patients and physicians. The most recent update of the diagnostic criteria subdivides functional dyspepsia into two subcategories based on the main symptom of epigastric pain or postmeal fullness. As we discuss in this review, several studies have shown significant overlap in symptoms and pathophysiology between functional dyspepsia, irritable bowel syndrome, and the spectrum of reflux disorders. This overlap in symptoms can be informative in helping us to understand the underlying pathophysiology, diagnostic approaches, and treatment strategies. The addition of diagnostic testing such as pH impedance manometry of the distal esophagus to the current common diagnostic tests might be helpful in distinguishing between functional dyspepsia and reflux disease. Importantly, various treatment modalities may be more effective than others if the main symptom is burning rather than pain or postmeal fullness rather than early satiation.

Modified chaihu shugan powder for functional dyspepsia: meta-analysis for randomized controlled trial

Context. Modified Chaihu Shugan powder (MCSP) is a popular traditional Chinese herbal formula for functional dyspepsia, which is revised from Chaihu Shugan San and recorded in a medical classic works of China. However, its role and effect in treating functional dyspepsia have not been well established. Objective. To assess the effect and safety of modified Chaihu Shugan powder for functional dyspepsia. Methods. We searched the published and unpublished studies up to August 2012. Only RCTs of modified Chaihu Shugan powder with or without prokinetic drugs versus prokinetic drugs in the patients diagnosed with functional dyspepsia were included. Results. Twenty-two clinical trials involving 1998 participants were included. There were evidences that modified Chaihu Shugan powder (RR = 1.20, 95%, CI 1.14 to 1.27) and modified Chaihu Shugan powder plus prokinetic drugs (RR = 1.18, 95%, CI 1.11 to 1.25) were significantly better treatment options than prokinetic drugs alone in improving symptoms. No serious adverse events were described in the included trials. Conclusions. This meta-analysis showed that modified Chaihu Shugan powder alone or in combination with prokinetic drugs might be more effective than prokinetic drugs alone. However, with poor methodological quality, all the included trials were at high risk of bias. Further large-scale high-quality trials are required for assessment.

Pathogenesis of functional dyspepsia

Functional dyspepsia (FD) is one of the most common clinical functional gastrointestinal disorders. As a chronic, relapsing and remitting disorder, FD not only significantly affects the quality of life of patients but also causes very high medical expenses. However, the specific pathogenesis of FD has always been a big problem for gastroenterologists. Recently, motility abnormalities, visceral hypersensitivity, psychosocial factors, Helicobacter pylori, genetic factors, excessive gastric acid secretion, environment, diet, and lifestyle have been proposed to explain the pathogenesis of FD, of which the brain-gut axis, autonomic nervous system , gastrointestinal hormones may play an important role. In this paper, we review the recent progress in the pathogenesis of FD.

Relationship between functional dyspepsia and Helicobacter pylori infection

Functional dyspepsia is one of the most common clinical functional gastrointestinal disorders. Currently, many pathogenic factors have been proposed to explain the pathogenesis of functional dyspepsia. Although the relationship between Helicobacter pylori (H. pylori) infection and functional dyspepsia has been studied extensively, the results obtained are contradictory. In recent years, the better understanding of functional dyspepsia and several revisions of the Roman standards have led to the revelation of shortcomings of previous studies. In this paper we discuss the relationship between H. pylori infection and functional dyspepsia.

Developmental origins of functional dyspepsia-like gastric hypersensitivity in rats

BACKGROUND & AIMS

Gastric hypersensitivity (GHS) contributes to epigastric pain in patients with functional dyspepsia (FD); the etiology and cellular mechanisms of this dysfunction remain unknown. We investigated whether inflammatory insult to the colons of neonatal rats induced GHS in adult life.

METHODS

We used cellular, molecular, and in vivo approaches to investigate the mechanisms of GHS in adult rats subjected to neonatal colonic insult by intraluminal administration of trinitrobenzene sulfonic acid; controls received saline. Six to 8 weeks later, rats were evaluated for GHS and tissue was collected for molecular experiments.

RESULTS

Inflammatory insult to the colon on post-natal day 10 caused an aberrant increase of corticosterone on post-natal day 15 and induced GHS in adult life. We called these FD-like rats. Inhibition of glucocorticoid receptors after neonatal insult blocked the induction of GHS in adult rats. The aberrant increase of plasma corticosterone in neonates increased the plasma concentration of norepinephrine, nerve growth factor in the gastric fundus muscularis externae, brain-derived neurotrophic factor in the thoracic dorsal root ganglia and spinal cord, and down-regulated K(v)1.1 messenger RNA in thoracic dorsal root ganglia without affecting the expression of K(v)1.4, Na(v)1.8, TrpA1, TrpV1, or P2X3 in FD-like rats. Inhibition of glucocorticoid receptors during neonatal insult or the inhibition of adrenergic receptors, nerve growth factor, or brain-derived neurotrophic factor in FD-like rats suppressed GHS. The intrathecal administration of small interfering RNAs against K(v)1.1 increased GHS in naive rats.

CONCLUSIONS

Inflammatory insult to the colons of rat pups leads to GHS in adult life. GHS is caused by altered expression of genes encoding neurotrophins and ion channels, and altered activity of the sympathetic nervous system.

Gastric hypochlorhydria is associated with an exacerbation of dyspeptic symptoms in female patients

BACKGROUND

Gender and gastric acid have been suggested to be independently involved in the pathophysiology of functional dyspepsia, but the interrelationship among gender, dyspeptic symptoms, and gastric acid secretion remains to be evaluated. We sought to explore this issue in dyspeptic patients.

METHODS

A total of 89 outpatients (male, 36; mean age, 55.6 years) with dyspeptic symptoms were analyzed. The degree of dyspeptic symptoms was evaluated and scored using a symptom questionnaire consisting of 3 subcategories: dysmotility-related symptoms, reflux-related symptoms, and epigastric pain-related symptoms. Stimulated gastric acid secretion was directly measured using an endoscopic gastrin test.

RESULTS

The total symptom scores and the epigastric pain-related symptom scores were significantly higher in female patients than in male patients. The dysmotility-related and reflux-related symptom scores were also higher, but not significantly, in the female patients. Multiple regression analysis of age, gender, habitual drinking, smoking, Helicobacter pylori infection, and gastric acid secretion revealed that gender and gastric hypochlorhydria, defined as less than 2.1 mEq/10 min in the endoscopic gastrin test, were significantly associated with higher dyspeptic symptom scores. The total scores and the dysmotility-related scores were significantly higher in the patients with gastric hypochlorhydria than in those with gastric non-hypochlorhydria, and this difference was found to be present only in females.

CONCLUSIONS

Gastric hypochlorhydria in female dyspeptic patients may be involved in the exacerbation of dyspeptic symptoms. Differences in the responsiveness to gastric hypochlorhydria between males and females may be partly responsible for the gender differences in the prevalence and severity of dyspeptic symptoms.

Relationship between Symptoms and Gastric Emptying of Solids in Functional Dyspepsia

Objective:

Functional dyspepsia is a heterogeneous disorder and different pathophysiological mechanisms underlie its symptom patterns. This study investigated the relationship between dyspepsia symptoms and overall and proximal gastric emptying in patients with functional dyspepsia.

Methods:

A total of 93 patients with functional dyspepsia and 32 healthy subjects were enrolled in this cross-sectional study. Prevalence and severity of eight dyspepsia symptoms were recorded. Gastric emptying was measured using single photon emission computed tomography scanning.

Results:

Overall and proximal gastric emptying were delayed in 47.3% (44/93) and 46.2% (43/93) of the patients, respectively. Logistic regression analyses showed that presence of nausea was associated with delayed proximal gastric emptying (odds ratio 4.951; 95% confidence interval 1.321, 18.558). There were no significant differences between normal and delayed overall gastric emptying according to presence of symptoms.

Conclusions:

Presence of nausea might indicate delayed gastric emptying of the proximal stomach. Promotion of proximal gastric emptying may constitute an effective therapy for patients with functional dyspepsia who report nausea as the dominant symptom.

Why dyspepsia can occur without organic disease: pathogenesis and management of functional dyspepsia

Functional dyspepsia (FD), one of the most common conditions in medicine, is a gastrointestinal disorder in which the patient suffers from chronic dyspeptic symptoms such as epigastralgia and a heavy feeling in the stomach despite the absence of organic disease. Elucidating the pathogenesis of FD means answering the question, "Why do symptoms occur?" The factors contributing to symptom manifestation in FD probably should be divided into 3 categories: (1) physiological abnormalities that directly induce symptoms, (2) factors that modify those physiological abnormalities, and (3) factors that govern abnormal responses to stress. The symptoms of FD are directly caused by two major physiological abnormalities-abnormal gastric motility and visceral hypersensitivity-occurring in patients who have acquired excessive responsiveness to stress as a result of the environment during early life, genetic abnormalities, residual inflammation after gastrointestinal infections, or other causes, with the process modified by factors including psychophysiological abnormalities, abnormal secretion of gastric acid, Helicobacter pylori infection, diet, and lifestyle. If the basis of this model of FD pathogenesis is excessive responsiveness of gastrointestinal function to stress and external stimuli, psychosomatic approaches to alter stress perception could be important treatment options. However, in the primary care setting, the treatment of FD has focused on local gastric factors, including abnormal gastric acid secretion, abnormal gastric motility, and H. pylori infection. Acid secretion inhibitors and prokinetics have been commonly used, and H. pylori eradication therapy has been carried out, but the effectiveness of drug therapy has been limited.

Relationship between symptoms and proximal stomach function in patients with functional dyspepsia

AIM: To investigate the prevalence of impaired proximal stomach function and its relationship to symptoms in patients with functional dyspepsia (FD).

METHODS: Fifty-nine patients with FD and 32 healthy subjects (HS) were enrolled in this study. After an overnight fast of at least 12 h, a double-lumen polyvinyl tube with an adherent plastic bag that was finely folded was introduced through the patient's mouth. A gastric barostat was used to evaluate proximal stomach function (sensitivity, accommodation and compliance). After an overnight fast, gastric emptying was measured by single photon emission computerized tomography (SPECT). The gastric emptying curve was plotted to calculate the gastric emptying half-time. Individual dyspepsia symptom scores were obtained for all patients and their relationship with proximal stomach function was assessed. Logistic regression analysis and χ² statistics were used to identify the association between proximal stomach function and symptoms.

RESULTS: Visceral hypersensitivity to gastric distention was found in 44.07% of the patients, and their gastric emptying half-time did not significantly differ from that of patients with normal sensitivity. Epigastric pain was significantly more prevalent in patients with visceral hypersensitivity than in those with normal sensitivity (P < 0.01). Epigastric pain was independently and significantly associated with hypersensitivity to gastric distention (OR = 4.430, P < 0.05). Impaired gastric accommodation was found in 37.29% of the patients, and their gastric emptying half-time did not differ from that of other patients. Impaired gastric accommodation to gastric distention was associated with a higher prevalence of early satiety (P < 0.05). The presence of early satiety was the only symptom that was independently associated with impaired accommodation to gastric distention (OR = 3.231, P < 0.05). Reduced compliance was found in 54.24% of the patients; however, no relationship was found between reduced compliance and dyspeptic symptoms.

CONCLUSION: Symptoms are associated with impaired proximal stomach function in patients with FD. Epigastric pain and early satiety can be used to predict the presence of hypersensitivity and impaired accommodation, respectively.

Life style in persons with functional gastrointestinal disorders--large-scale internet survey of lifestyle in Japan

BACKGROUND

Care of patients with functional gastrointestinal disorders (FGIDs) commonly includes offering guidance on diet, exercise, and other lifestyle factors, but there is little information available on the actual lifestyles of FGID sufferers.

METHODS

An internet questionnaire survey of 15,000 adult members of the general public in Japan who were screened for functional dyspepsia (FD) and irritable bowel syndrome (IBS) using the Rome III adult FGID questionnaire was conducted.

KEY RESULTS

The prevalence of FD and IBS was 6.5% and 14.0%, respectively, and 3.0% of the subjects met the criteria for both FD and IBS. The prevalence of both FD and IBS was higher in women than in men. The lifestyles of 2,547 subjects who met the Rome III criteria for FD, IBS, or both were compared with the lifestyles of 1,000 control subjects who did not meet the criteria for FD or the criteria for IBS. Compared to the control subjects, a significantly lower percentage of subjects with FD, IBS, or both exercised frequently, and a significantly higher percentage thought that their sleep was insufficient, ate meals irregularly, did not have an appetite, did not like meat, thought that their vegetable consumption was insufficient, felt stress in their daily lives, and regarded themselves as being highly susceptible to stress.

CONCLUSIONS & INFERENCES

Persons with FGIDs are affected by impairment of sleep, eating habits, diet, exercise and other lifestyle factors, and feel excessive stress. This suggests that offering lifestyle guidance to FGID patients may be useful.

Asian consensus report on functional dyspepsia

BACKGROUND AND AIM

Environmental factors such as food, lifestyle and prevalence of Helicobacter pylori infection are widely different in Asian countries compared with the West, and physiological functions and genetic factors of Asians may also be different from those of Westerners. Establishing an Asian consensus for functional dyspepsia is crucial in order to attract attention to such data from Asian countries, to articulate the experience and views of Asian experts, and to provide a relevant guide on management of functional dyspepsia for primary care physicians working in Asia.

METHODS

Consensus team members were selected from Asian experts and consensus development was carried out by using a modified Delphi method. Consensus teams collected published papers on functional dyspepsia especially from Asia and developed candidate consensus statements based on the generated clinical questions. At the first face-to-face meeting, each statement was reviewed and e-mail voting was done twice. At the second face-to-face meeting, final voting on each statement was done using a keypad voting system. A grade of evidence and strength of recommendation were applied to each statement according to the method of the GRADE Working Group.

RESULTS

Twenty-nine consensus statements were finalized, including seven for definition and diagnosis, five for epidemiology, nine for pathophysiology, and eight for management. Algorithms for diagnosis and management of functional dyspepsia were added.

CONCLUSIONS

  This consensus developed by Asian experts shows distinctive features of functional dyspepsia in Asia and will provide a guide to the diagnosis and management of functional dyspepsia for Asian primary care physicians.

Asian consensus report on functional dyspepsia

BACKGROUND/AIMS

Environmental factors such as food, lifestyle and prevalence of Helicobacter pylori infection are widely different in Asian countries compared to the West, and physiological functions and genetic factors of Asians may also be different from those of Westerners. Establishing an Asian consensus for functional dyspepsia is crucial in order to attract attention to such data from Asian countries, to articulate the experience and views of Asian experts, and to provide a relevant guide on management of functional dyspepsia for primary care physicians working in Asia.

METHODS

Consensus team members were selected from Asian experts and consensus development was carried out using a modified Delphi method. Consensus teams collected published papers on functional dyspepsia especially from Asia and developed candidate consensus statements based on the generated clinical questions. At the first face-to-face meeting, each statement was reviewed and e-mail voting was done twice. At the second face-to-face meeting, final voting on each statement was done using keypad voting system. A grade of evidence and a strength of recommendation were applied to each statement according to the method of the GRADE Working Group.

RESULTS

Twenty-nine consensus statements were finalized, including 7 for definition and diagnosis, 5 for epidemiology, 9 for pathophysiology and 8 for management. Algorithms for diagnosis and management of functional dyspepsia were added.

CONCLUSIONS

This consensus developed by Asian experts shows distinctive features of functional dyspepsia in Asia and will provide a guide to the diagnosis and management of functional dyspepsia for Asian primary care physicians.