Symptoms associated with hypersensitivity to gastric distention in functional dyspepsia

Updated document on the management of functional dyspepsia by the Asociación Española de Neurogastroenterologia y Motilidad (ASENEM) and Sociedad Española de Medicina Familiar y Comunitaria (semFYC)

Functional dyspepsia (FD) is a gut-brain axis disorder characterized by postprandial fullness, early satiety, bloating and/or epigastric pain, which are presumed to originate in the gastroduodenal tract. While the international recommendations in the Rome IV consensus require endoscopy to rule out an organic condition before establishing a diagnosis of FD, international guidelines recommend that, in the absence of risk factors, patient management be initiated at the primary care level by establishing Helicobacter pylori infection status, with eradication when positive, followed by empiric therapy with proton pump inhibitors and/or prokinetics, and that endoscopy be reserved for patients refractory to said measures. Second-line therapy includes neuromodulating agents, among which tricyclic antidepressants and atypical antipsychotics such as levosulpiride stand out. The latter has a predominant prokinetic effect, hence it is also used as first-line therapy for patients where early satiety and postprandial fullness predominate. Other therapy alternatives include phytotherapy using STW5 or peppermint/caraway oil, which have shown their superiority over placebo in controlled studies. Concurrently, dietary and lifestyle counseling, as well as psychological interventions such as cognitive-behavioral therapy, when available, may represent a therapeutic alternative worth considering for some patients.

European Guideline on Chronic Nausea and Vomiting-A UEG and ESNM Consensus for Clinical Management

INTRODUCTION

Chronic nausea and vomiting are symptoms of a wide range of gastrointestinal and non-gastrointestinal conditions. Diagnosis can be challenging and requires a systematic and well-structured approach. If the initial investigation for structural, toxic and metabolic disorders is negative, digestive motility and gut-brain interaction disorders should be assessed. United European Gastroenterology (UEG) and the European Society for Neurogastroenterology and Motility (ESNM) identified the need for an updated, evidence-based clinical guideline for the management of chronic nausea and vomiting.

METHODS

A multidisciplinary team of experts in the field, including European specialists and national societies, participated in the development of the guideline. Relevant questions were addressed through a literature review and statements were developed and voted on according to a Delphi process.

RESULTS

Ninety-eight statements were identified and voted following the Delphi process. Overall agreement was high, although the grade of scientific evidence was low in many areas. Disagreement was more evident for some pharmacological treatment options. A diagnostic algorithm was developed, focussing on the differentiating features between gastrointestinal motility and gut-brain interaction disorders with predominant nausea and vomiting.

CONCLUSION

These guidelines provide an evidence-based framework for the evaluation and treatment of patients with chronic nausea and vomiting.

Randomized clinical trial: the effects of mirtazapine in functional dyspepsia patients

Background

Functional dyspepsia (FD) is one of the most common gastrointestinal disorders worldwide. Currently, anti-gastric drugs, gastric acid inhibitors, prokinetic drugs, and mucosal protective drugs are widely used in FD patients, however, only a small proportion of patients benefit from these drugs. Studies reported mirtazapine may improve symptoms of FD patients but the efficacy and safety of mirtazapine in the treatment of FD is unclear.

Objectives

To investigate the efficacy and safety of mirtazapine in FD patients.

Design

We performed a prospective, single-randomized, two-group parallel clinical trial involving 120 FD patients with poor traditional drug treatment outcomes to evaluate the efficacy and safety of mirtazapine.

Methods

Qualified patients identified through the screening assessments were randomly divided into two groups: mirtazapine group (n = 60) treated with mirtazapine 15 mg qn on top of traditional drugs, and control group (n = 60) who continued to be treated with traditional drugs. Subjects were evaluated for meal-related symptoms and severity, quality of life, gastrointestinal-specific anxiety, and body weight before and after the 8-week intervention. Adverse reactions were also recorded.

Results

At the end of 8-week treatment, dyspeptic symptoms in the mirtazapine group were significantly relieved compared with the baseline (7.95 ± 1.86 vs 11.17 ± 2.14, p < 0.001). Assessment of the impact of dyspepsia on patients' quality of life from the short form-Nepean Dyspepsia Index showed that patients generally feel better in mirtazapine group than control group (24.52 ± 2.87 vs 28.64 ± 4.32, p < 0.001). Mirtazapine group also showed significant weight gain and decreased visceral sensitivity index score.

Conclusion

Compared with control group, 8-week administration of mirtazapine significantly improved the overall severity of symptoms of dyspepsia (such as individual symptoms of postprandial fullness, early satiation, nausea, and vomiting), gastrointestinal-specific anxiety, quality of life, and increased weight in FD patients. This study provided clues to clinicians that mirtazapine may be a good choice for the treatment of FD patients.

Trial registration

This study was registered in the Chinese clinical trial registry (https://www.chictr.org.cn/index.html, protocol No. ChiCTR2100048304).

Functional Dyspepsia and Gastroesophageal Reflux Disease: From Pathogenesis to Current Treatment Strategies

Aim: to present a modern view on the combination of functional dyspepsia (FD) and gastroesophageal reflux disease (GERD) and to evaluate the effectiveness of acotiamide in patients with FD and GERD.

Key points. The high frequency of the combination of FD and GERD is caused by common pathogenetic mechanisms and presents an urgent problem in clinical practice. The concurrent occurrence of these diseases alters the clinical picture, complicates differential diagnostics, and leads to inadequate prescription of drugs. Medical treatment for patients with FD and GERD includes the use of proton pump inhibitors (PPIs) and prokinetics. Currently, acotiamide is recognized as an effective drug that affects the motility of the upper gastrointestinal tract. Acotiamide is an antagonist of muscarinic M1 and M2 receptors and a reversible inhibitor of acetylcholinesterase. The clinical efficacy of this drug has been demonstrated not only in patients with FD but also in those with a combination of FD and GERD.

Conclusion. Administration of acotiamide is pathogenetically justified in patients with the combination of GERD and FD.

Development of a Standard Tool of Pattern Identification for Functional Dyspepsia: A Cross-Sectional Study from Korea

BACKGROUND/OBJECTIVE

The diagnosis and treatment of functional dyspepsia (FD) require a systematic and tailored approach. In traditional Korean medicine (TKM), pattern-identification tools help analyze clinical information and guide treatment. This study aimed to develop a Korean version of the standard tool of pattern identification for functional dyspepsia (STPI-FD) and subsequently assess its reliability and validity.

METHODS

Common patterns and symptoms were identified through a systematic review of the clinical studies conducted in Korea and China. An importance survey for each pattern and symptom was conducted using the Delphi method and refined through expert consensus. A draft STPI-FD comprising six patterns and 38 items was developed. Ninety-five patients with FD completed the STPI-FD along with the Visual Analog Scale, Total Dyspepsia Symptom scale, Single Dyspepsia Symptom scale, and Functional Dyspepsia-related Quality of Life questionnaire.

RESULTS

Two items were excluded from the STPI-FD due to their negative impact on reliability, resulting in a 36-item tool. The revised STPI-FD demonstrated high internal consistency, with an overall Cronbach's alpha of 0.942. In contrast, the Cronbach's alpha values for each pattern ranged from 0.7 to 0.9. To assess its validity, significant differences in the pattern characteristics and associated symptoms were confirmed, indicating its clinical relevance. Statistically significant positive correlations between the revised STPI-FD and other dyspepsia-related scales underscore the differentiation between patterns.

CONCLUSION

The final STPI-FD is a moderately reliable and valid tool for diagnosing specific patterns in FD, supporting the selection of interventions and the evaluation of symptom improvement in patients treated with TKM.

Plasticity of gastrointestinal vagal afferents in terms of feeding-related physiology and pathophysiology

Gastrointestinal vagal afferents play an important role in communicating food related information from the gut to the brain. This information initiates vago-vagal reflexes essential for gut functions, including gut motility and secretions. These afferents also play a role in energy homeostasis, signalling the arrival, amount and nutrient composition of a meal to the central nervous system where it is processed ultimately leading to termination of a meal. Vagal afferent responses to food related stimuli demonstrate a high degree of plasticity, responding to short term changes in nutritional demand, such as the fluctuations that occur across a 24-hr or in response to a fast, as well as long term changes in energy demand, such as occurs during pregnancy. This plasticity is disrupted in disease states, such as obesity or chronic stress where there is hypo- and hypersensitivity of these afferents, respectively. Improved understanding of the plasticity of these afferents will enable identification of new treatment options for diseases associated with vagal afferent function.

Insights and future prospects of traditional Chinese medicine in the treatment of functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a prevalent and challenging gastrointestinal disorder. Conventional medicine often faces limitations in providing effective treatment for FD, thus indicating the need to explore alternative approaches. Traditional Chinese medicine (TCM), which is rooted in ancient Chinese traditions and has evolved over thousands of years, offers a holistic approach to well-being. TCM incorporates herbal remedies, acupuncture, and other therapies while shaping the future of complementary and alternative medicine.

PURPOSE

To review the existing literature on the current status and future prospects of using TCM to treat FD.

METHODS

We extensively searched the PubMed, Google Scholar, Embase, an China National Knowledge Internet databases from inception to May 31, 2023 to identify relevant literature. We also searched the reference lists of the included articles.

RESULTS

Clinical evidence-based research has explored the efficacy of TCM in treating FD. Recent research has illuminated the multifaceted mechanisms through which TCM interventions affect FD. TCM is a promising alternative, as it emphasizes a holistic approach and holds potential advantages in addressing the complex nature of FD.

CONCLUSIONS

The integration of TCM and Western medicine offers a comprehensive approach to understanding and managing FD by bridging traditional wisdom with modern scientific understanding. This paper highlights the practical implications of this integration, the challenges to be addressed, and the potential for international collaboration to further elucidate the efficacy of TCM. However, continued research and dialog are needed to advance the modern development of TCM and to improve the quality of life of FD patients.

Coeliac disease is a strong risk factor for Gastro-oesophageal reflux disease while a gluten free diet is protective: a systematic review and meta-analysis

Background

Gastro-oesophageal reflux disease (GORD) mechanisms are well described, but the aetiology is uncertain. Coeliac disease (CD), a gluten enteropathy with increased duodenal eosinophils overlaps with GORD. Functional dyspepsia is a condition where duodenal eosinophilia is featured, and a 6-fold increased risk of incident GORD has been observed. Perturbations of the duodenum can alter proximal gastric and oesophageal motor function. We performed a systematic review and meta-analysis assessing the association between CD and GORD.

Methods

A systematic search of studies reporting the association of GORD and CD was conducted. CD was defined by combined serological and histological parameters. GORD was defined based on classical symptoms, oesophagitis (endoscopic or histologic) or abnormal 24-h pH monitoring; studies reporting oesophageal motility abnormalities linked with GORD were also included. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using a random-effects model.

Findings

31 papers were included. Individuals with CD on a gluten containing diet were 3 times more likely to have GORD than controls (OR: 3.37, 95% CI: 2.09-5.44), and over 10 times more likely when compared to those on a gluten free diet (GFD) (OR: 10.20, 95% CI: 6.49-16.04). Endoscopic oesophagitis was significantly associated with CD (OR: 4.96; 95% CI: 2.22-11.06). One year of a GFD in CD and GORD was more efficacious in preventing GORD symptom relapse than treatment with 8 weeks of PPI in non-CD GORD patients (OR: 0.18, 95% CI: 0.08-0.36). Paediatric CD patients were more likely to develop GORD (OR: 3.29, 95% CI: 1.46-7.43), compared to adult CD patients (OR: 2.55, 95% CI: 1.65-3.93).

Interpretation

CD is strongly associated with GORD but there was high heterogeneity. More convincingly, a GFD substantially improves GORD symptoms, suggesting a role for duodenal inflammation and dietary antigens in the aetiology of a subset with GORD. Ruling out CD in patients with GORD may be beneficial.

Funding

The study was supported by an Investigator Grant from the NHMRC to Dr. Talley.

Effects of corticotropin-releasing hormone on gastric electrical activity and sensorimotor function in healthy volunteers: a double-blinded crossover study

Biopsychosocial factors are associated with disorders of gut-brain interaction (DGBI) and exacerbate gastrointestinal symptoms. The mechanisms underlying pathophysiological alterations of stress remain unclear. Corticotropin-releasing hormone (CRH) is a central regulator of the hormonal stress response and has diverse impact on different organ systems. The aim of the present study was to investigate the effects of peripheral CRH infusion on meal-related gastrointestinal symptoms, gastric electrical activity, and gastric sensorimotor function in healthy volunteers (HVs). In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effects of CRH on gastric motility and sensitivity. HVs were randomized to receive either peripheral-administered CRH (100 µg bolus + 1 µg/kg/h) or placebo (saline), followed by at least a 7-day washout period and assignment to the opposite treatment. Tests encompassed saliva samples, gastric-emptying (GE) testing, body surface gastric mapping (BSGM, Gastric Alimetry; Alimetry) to assess gastric myoelectrical activity with real-time symptom profiling, and a gastric barostat study to assess gastric sensitivity to distention and accommodation. Twenty HVs [13 women, mean age 29.2 ± 5.3 yr, body mass index (BMI) 23.3 ± 3.8 kg/m2] completed GE tests, of which 18 also underwent BSGM measurements during the GE tests. The GE half-time decreased significantly after CRH exposure (65.2 ± 17.4 vs. 78.8 ± 24.5 min, P = 0.02) with significantly increased gastric amplitude [49.7 (34.7-55.6) vs. 31.7 (25.7-51.0) µV, P < 0.01], saliva cortisol levels, and postprandial symptom severity. Eleven HVs also underwent gastric barostat studies on a separate day. However, the thresholds for discomfort during isobaric distensions, gastric compliance, and accommodation did not differ between CRH and placebo.NEW & NOTEWORTHY In healthy volunteers, peripheral corticotropin-releasing hormone (CRH) infusion accelerates gastric-emptying rate and increases postprandial gastric response, accompanied by a rise in symptoms, but does not alter gastric sensitivity or meal-induced accommodation. These findings underscore a significant link between stress and dyspeptic symptoms, with CRH playing a pivotal role in mediating these effects.

Meal related symptoms in youth with chronic abdominal pain: Relationship to anxiety, depression, and sleep dysfunction

OBJECTIVE

The objective of the current study was to describe meal-related symptoms in youth with chronic abdominal pain fulfilling criteria for a disorder of gut-brain interaction (DGBI) and their associations with anxiety, depression, and sleep disturbances.

METHODS

This was a retrospective evaluation of 226 consecutive patients diagnosed with an abdominal pain-associated DGBI. As part of routine care, all had completed a standardized symptom history, the Sleep Disturbances Scale for Children (utilized to assess for disorders of initiation and maintenance of sleep and excessive daytime somnolence) and the Behavior Assessment System for Children-Third Edition (utilized to assess for anxiety and depression). Four meal related symptoms were assessed: early satiety, postprandial bloating, postprandial abdominal pain, and postprandial nausea.

RESULTS

Overall, 87.6% of patients reported at least one meal related symptom and the majority reported at least three symptoms. All meal related symptoms were significantly related to each other. Postprandial pain and nausea were more often reported by females. Early satiety, postprandial bloating, and postprandial nausea, but not postprandial pain demonstrated significant though variable associations with anxiety, depression, disorders of initiation and maintenance of sleep, and disorders of excessive somnolence, but only in adolescents.

CONCLUSIONS

Meal related symptoms are very common in youth with abdominal pain-associated DGBIs. Early satiety, bloating, and postprandial nausea demonstrate variable associations with anxiety, depression, and disordered sleep while increased postprandial pain was not associated with psychologic or sleep dysfunction, suggesting a different pathway for symptom generation.

Laminarin ameliorates iodoacetamide-induced functional dyspepsia via modulation of 5-HT3 receptors and the gut microbiota

Visceral and somatic hypersensitivity is a common cause of functional dyspepsia. Marine bioactive components have been revealed to possess numerous valuable abilities. However, as a kind of polysaccharide extracted from brown algae, the study focused on the biological properties of laminarin is still limited, especially in gastrointestinal disorders. In our study, indicators associated with visceral sensational function and gastrointestinal microecology were determined to investigate the modulatory effects of laminarin on functional dyspepsia induced by iodoacetamide. Mice with visceral hypersensitivity were orally administrated with laminarin (50 and 100 mg per kg bw) for fourteen days. The results indicated that laminarin partly alleviated the dysfunction by regulating corticosterone secretion, the expression of 5HT3 receptors at both protein and mRNA levels, and mechanical transduction through the PIEZO2-EPAC1 axis. Furthermore, laminarin administration moderated the imbalanced gut microbial profile, including modulating the abundance of Bacteroidetes and Firmicutes. Our findings revealed that laminarin may restore the overexpression of 5HT3 receptors, the abnormal mechanical transduction, and impaired gut microecology. In conclusion, we provide evidence to support the utilization of laminarin as the ingredient of complementary and alternative medicine of regulating visceral and somatic hypersensitivity.

Analgesic Effects of Vagus Nerve Stimulation on Visceral Hypersensitivity: A Direct Comparison Between Invasive and Noninvasive Methods in Rats

OBJECTIVES

The aims of this study were to investigate analgesic effects of vagus nerve stimulation (VNS) on visceral hypersensitivity (VH) in a rodent model of functional dyspepsia (FD) and to compare invasive VNS with noninvasive auricular VNS (aVNS).

MATERIALS AND METHODS

Eighteen ten-day-old male rats were gavaged with 0.1% iodoacetamide (IA) or 2% sucrose solution for six days. After eight weeks, IA-treated rats were implanted with electrodes for VNS or aVNS (n = 6 per group). Different parameters, varying in frequency and stimulation duty cycle, were tested to find the best parameter based on the improvement of VH assessed by electromyogram (EMG) during gastric distension.

RESULTS

Compared with sucrose-treated rats, visceral sensitivity was increased significantly in IA-treated "FD" rats and ameliorated remarkably by VNS (at 40, 60, and 80 mm Hg; p ≤ 0.02, respectively) and aVNS (at 60 and 80 mm Hg; p ≤ 0.05, respectively) with the parameter of 100 Hz and 20% duty cycle. There was no significant difference in area under the curve of EMG responses between VNS and aVNS (at 60 and 80 mm Hg, both p > 0.05). Spectral analysis of heart rate variability revealed a significant enhancement in vagal efferent activity while applying VNS/aVNS compared with sham stimulation (p < 0.01). In the presence of atropine, no significant differences were noted in EMG after VNS/aVNS. Naloxone blocked the analgesic effects of VNS/aVNS.

CONCLUSIONS

VNS/aVNS with optimized parameter elicits ameliorative effects on VH, mediated by autonomic and opioid mechanisms. aVNS is as effective as direct VNS and has great potential for treating visceral pain in patients with FD.

Efficacy of Bifidobacterium animalis subsp. lactis BL-99 in the treatment of functional dyspepsia: a randomized placebo-controlled clinical trial

Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.

Efficacy of Bifidobacterium animalis subsp. lactis BL-99 in the treatment of functional dyspepsia: a randomized placebo-controlled clinical trial

Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.

Impaired gastric accommodation in patients with postprandial distress syndrome type of functional dyspepsia assessed by 2D ultrasonography

BACKGROUND AND PURPOSE

The pathophysiology of postprandial distress syndrome includes impaired gastric accommodation, hypersensitivity to gastric distension and delayed gastric emptying. 2D-ultrasonography is one of the methods to assess gastric accommodation by measuring proximal gastric area and we evaluated its role in calculating proximal gastric area and thus assessing gastric accommodation in Indian patients with postprandial distress syndrome.

METHODS

In a hospital-based comparative analysis, proximal gastric area was measured with 2D-ultrasonography of postprandial distress syndrome (PDS) patients and compared with healthy controls. Five readings were measured every five minutes till 25 minutes after 400 mL of vegetable soup. The Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life (PAGI-QOL score) and diets aggravating PDS symptoms were studied through detailed questionnaires. Sample size was calculated at 80% study power and alpha error of 0.05 to be 30 subjects in each group.

RESULTS

The mean age of patients (18 males) vs. 30 healthy controls (25 males) was 40.8 ± 11.50 years vs. 36.37 ± 7.58, respectively, (p = 0.084). Proximal gastric area was significantly lower in patients versus healthy controls at five minutes (22.54 ± 2.77 vs. 30.66 ± 2.55 cm2), 10 minutes (23.03 ± 2.45 vs. 31.10 ± 2.06 cm2), 15 minutes (23.06 ± 2.27 vs. 30.31 ± 2.11 cm2), 20 minutes (22.21 ± 2.31 vs. 29.73 ± 1.71 cm2) and 25 minutes (22.02 ± 2.33 vs. 28.39 ± 1.55 cm2); p < 0.001 at all intervals of time, indicating impaired gastric accommodation. The QOL was poor in all patients with PDS with mean PAGI-QOL score of 31.30 ± 15.05, median of 30, minimum score of 12 and maximum score of 66.

CONCLUSIONS

Measurement of proximal gastric area with 2D-ultrasonography is simple and non-invasive. Proximal gastric area in patients was lower than controls, indicating impaired gastric accommodation. Poor quality of life was universal in patients with postprandial distress syndrome.

Esophageal Reflux Hypersensitivity: A Comprehensive Review

Reflux hypersensitivity (RH) is one of the phenotypes of gastroesophageal reflux disease. The latest Rome IV defines RH as a condition with typical reflux symptoms and positive reflux-symptom association despite normal acid exposure. Subsequently, the Lyon consensus proposed detailed cutoff values for the criteria on the basis of experts' consensus. Rome IV brought a clear-cut perspective into the pathophysiology of gastroesophageal reflux disease and the importance of esophageal hypersensitivity. This perspective can be supported by the fact that other functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia often overlap with RH. Although several possible pathophysiological mechanisms of esophageal hypersensitivity have been identified, there is still unmet medical needs in terms of treatment for this condition. This review summarizes the current knowledge regarding RH.

Brief cognitive-behavioral treatment for avoidant/restrictive food intake disorder in the context of functional dyspepsia: Study protocol for a feasibility randomized controlled trial

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) symptoms are common (up to 40%) among adults with functional dyspepsia (FD), a disorder of gut-brain interaction characterized by early satiation, post-prandial fullness, epigastric pain, and/or epigastric burning. Using an 8-session exposure-based cognitive-behavioral treatment (CBT) for adults with FD + ARFID compared to usual care (UC) alone, we aim to: (1) determine feasibility, (2) evaluate change in clinical outcomes in, and (3) explore possible mechanisms of action.

METHODS

We will randomize adults with FD who meet criteria for ARFID with ≥5% weight loss (N = 50) in a 1:1 ratio to CBT (with continued UC) or to UC alone. A priori primary benchmarks will be: ≥75% eligible participants enroll; ≥75% participants complete assessments; ≥70% participants attend 6/8 sessions; ≥70% of sessions have all content delivered; ≥70% participants rate Client Satisfaction Questionnaire scores above scale midpoint. We will also examine the size of changes in FD symptom severity and related quality of life within and between groups, and explore possible mechanisms of action.

CONCLUSIONS

Findings from this trial will inform next steps with treatment development or evaluation-either for further refinement or for next-step efficacy testing with a fully-powered clinical trial.

Belching Disorders and Rumination Syndrome: A Literature Review

BACKGROUND

Belching disorders and rumination syndrome (RS) are disorders of gut-brain interaction (DGBIs) in Rome IV. Belching disorders are composed of excessive gastric belching (GB) and supragastric belching (SGB). Excessive GB is related to physiological phenomenon whereas excessive SGB and RS are behavioral disorders.

SUMMARY

A recent large internet survey found that prevalence of belching disorders and RS were 1% and 2.8%, respectively. It has been recognized that not a few patients with two behavioral disorders, excessive SGB and RS, could be misdiagnosed as proton pump inhibitors (PPI)-refractory gastroesophageal reflux disease (GERD). In patients with reflux symptoms, distinguishing these conditions is essential because they need psychological treatment (i.e., cognitive behavioral therapy (CBT) rather than acid suppressants. Clinicians should take a medical history meticulously first to identify possible excessive SGB and/or RS. High-resolution impedance manometry and/or 24-h impedance-pH monitoring can offer an objective diagnosis of the disorders. Several therapeutic options are available for excessive SGB and RS. The first-line therapy should be CBT using diaphragmatic breathing that can stop the behaviors involving complex muscle contraction (e.g., abdominal straining) to generate SGB or rumination. Overlap with eating disorders and/or other DGBIs such as functional dyspepsia can make management of the behavioral disorders challenging since such coexisting conditions often require additional treatments.

KEY MESSAGES

Excessive SGB and RS are not unusual conditions. It is important to raise awareness of the behavioral disorders for appropriate management.

Patients with postprandial distress syndrome experience problems with their interoceptive perceptual function to the gastric region, but their heartbeat perception is normal: a case control study

BACKGROUND

Visceral hypersensitivity in functional dyspepsia can be localized or widespread, and there is no simple method of assessment. Measuring interoceptive accuracy at different sites provides an assessment of perceptual hypersensitivity to specific ecological phenomena. The purpose of this study was to characterize visceral hypersensitivity by comparing gastric sensory and cardiac perceptual tests in patients with postprandial distress syndrome and in healthy volunteers.

METHODS

Sixteen patients with postprandial distress syndrome (age = 47.5 ± 17.4, all female) and 16 healthy volunteers (age = 43.3 ± 16.1, all female) participated in the study after a six-hour fast. Each participant answered questionnaires about physical and mental quality of life, depression and anxiety, tendency of alexithymia, and somatosensory amplification. After completing the questionnaire, the participants took the heartbeat tracking task and the five-minute water load test. We performed statistical analysis using the Mann-Whitney U test and Spearman's rank correlation coefficient.

RESULTS

Subjects with postprandial distress syndrome had a lower drinking capacity than healthy volunteers (postprandial distress syndrome = 360.9 ± 170.0 mL, healthy volunteers = 644.1 ± 297 mL, P = 0.009), but there was no significant difference in the heartbeat perception score (postprandial distress syndrome = 0.599 ± 0.175, healthy volunteers = 0.623 ± 0.181, P = 0.647). There was a negative correlation (r = - 0.509, P < 0.05) between drinking capacity and the heartbeat perception score in healthy volunteers, but no correlation in postprandial distress syndrome (r = - 0.156, P = 0.564). Heartbeat perception score did not correlate with psychological measures.

CONCLUSIONS

Compared with healthy volunteers, only the five-minute water load test values were reduced in patients with postprandial distress syndrome, and no difference was observed in the heartbeat tracking task. Combining the 5-minute water load test and the heart rate tracking task revealed a lost cardiac-gastric perceptual relationship in patients with postprandial distress syndrome that was not observed in healthy volunteers, suggesting that there is hypersensitivity in gastric interoceptive perceptual function. Performing sensory examinations at two different sites may be useful in clarifying whether visceral hypersensitivity is localized.

TRIAL REGISTRATION

UMIN000057586. Registered11 March 2023(retrospectively registered).

Comparison of pancreatic enzyme abnormalities and protease-activated receptor-2-positive eosinophils in the duodenum of patients with functional dyspepsia-irritable bowel syndrome overlap with functional dyspepsia alone in Asian populations

BACKGROUND AND AIM

Some patients with functional gastrointestinal disorders exhibit pancreatic dysfunctions and pancreatic enzyme abnormalities. Thus, we aimed to clarify whether significant differences in clinical characteristics, prevalence of pancreatic enzyme abnormalities, duodenal inflammation, and protease-activated receptor 2 (PAR2) expression levels related to hypersensitivity exist between functional dyspepsia (FD) alone and FD-irritable bowel syndrome (IBS) overlap group.

METHODS

Ninety-three patients based on the Rome IV criteria, FD alone (n = 44) and FD overlapped with IBS (n = 49) group were enrolled. The patients scored their own clinical symptoms after consuming high-fat meals. Serum trypsin, PLA2, lipase, p-amylase, and elastase-1 levels were measured. PAR2, eotaxin-3, and TRPV4 mRNA levels in duodenum were determined using real-time polymerase chain reaction methods. PRG2- and PAR2 in the duodenum were evaluated using immunostaining.

RESULTS

FD score and global GSRS in patients with FD-IBS overlap were significantly higher than FD alone. Although the prevalence of pancreatic enzyme abnormalities in patients with FD alone was significantly (P < 0.01) higher than that in FD-IBS overlap, the ratio of aggravation of clinical symptoms following high-fat intake in patients with FD-IBS overlap was significantly higher (P = 0.007) than that in patients with FD alone. PAR2- and PRG2-double positive cells were localized in the degranulated eosinophils in the duodenum of patients with FD-IBS overlap. The number of PAR2- and PRG2-double positive cells in FD-IBS overlap was significantly (P < 0.01) higher than FD alone.

CONCLUSIONS

Pancreatic enzyme abnormalities and PAR2 expression on degranulated eosinophils infiltrations in the duodenum may be associated with the pathophysiology of patients with FD-IBS overlap in Asian populations.

Functional Dyspepsia: Current Understanding and Future Perspective

BACKGROUND

Functional dyspepsia (FD) is a common disorder characterized by chronic or recurrent upper abdominal pain or discomfort without any structural abnormalities in the gastrointestinal tract. FD is categorized into two subgroups based on symptoms: postprandial distress syndrome (PDS) and epigastric pain syndrome.

SUMMARY

The pathophysiology of FD involves several mechanisms. Delayed gastric emptying is observed in approximately 30% of FD patients but does not correlate with symptom patterns or severity. Impaired gastric accommodation is important in the pathophysiology, particularly for PDS. Visceral hypersensitivity, characterized by heightened sensitivity to normal activities, contributes to the perception of discomfort or pain in FD. Alterations to the duodenal mucosa, including impaired mucosal barrier function and low-grade inflammation, are also implicated in the pathogenesis of FD. Microbial dysbiosis and psychological factors such as stress can further exacerbate symptoms. Treatment options include dietary modifications, establishing a physician-patient relationship, acid suppressants, prokinetics, neuromodulators, and behavioral therapies. Dietary recommendations include eating smaller, more frequent meals, and avoiding trigger foods. Acid suppressants are used as the first-line treatment. Prokinetics and neuromodulators aim to improve gastric motility and central pain processing, respectively. Behavioral therapies, including cognitive behavioral therapy and hypnotherapy, have shown benefits for refractory FD. Severe and refractory cases may require combination therapies or experimental treatments.

KEY MESSAGES

FD is a disorder of gut-brain interaction involving diverse pathophysiological mechanisms. Individualized treatment based on symptoms and responses to interventions is crucial. Further research is needed to improve the understanding of FD and advance the development of effective therapies.

The Intersection of Disorders of Gut-Brain Interaction With Avoidant/Restrictive Food Intake Disorder

High rates of overlap exist between disorders of gut-brain interaction (DGBI) and eating disorders, for which common interventions conceptually conflict. There is particularly increasing recognition of eating disorders not centered on shape/weight concerns, specifically avoidant/restrictive food intake disorder (ARFID) in gastroenterology treatment settings. The significant comorbidity between DGBI and ARFID highlights its importance, with 13% to 40% of DGBI patients meeting full criteria for or having clinically significant symptoms of ARFID. Notably, exclusion diets may put some patients at risk for developing ARFID and continued food avoidance may perpetuate preexisting ARFID symptoms. In this review, we introduce the provider and researcher to ARFID and describe the possible risk and maintenance pathways between ARFID and DGBI. As DGBI treatment recommendations may put some patients at risk for developing ARFID, we offer recommendations for practical treatment management including evidence-based diet treatments, treatment risk counseling, and routine diet monitoring. When implemented thoughtfully, DGBI and ARFID treatments can be complementary rather than conflicting.

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.

Review article: Functional dyspepsia-a gastric disorder, a duodenal disorder or a combination of both?

BACKGROUND

Functional dyspepsia (FD) is one of the most frequent conditions in gastroenterological outpatient health care. Most recent research in FD has shifted its focus to duodenal pathophysiological mechanisms, although current treatments still focus mainly the stomach.

AIM

The aim of the study was to provide a comprehensive overview of the pathophysiology of FD focusing on a paradigm shift from gastric towards duodenal mechanisms.

METHODS

We conducted a literature search in PubMed for studies describing mechanisms that could possibly cause FD.

RESULTS

The pathophysiology of FD remains incompletely understood. Recent studies show that duodenal factors such as acid, bile salt exposure and eosinophil and mast cell activation correlate with symptom pattern and burden and can be associated with gastric sensorimotor dysfunction. The evolving data identify the duodenum an interesting target for new therapeutic approaches. Furthermore, the current first-line treatment, that is proton pump inhibitors, reduces duodenal low-grade inflammation and FD symptoms.

CONCLUSION

Future research for the treatment of FD should focus on the inhibition of duodenal mast cell activation, eosinophilia and loss of mucosal integrity.

Understanding neuroimmune interactions in disorders of gut-brain interaction: from functional to immune-mediated disorders

Functional gastrointestinal disorders-recently renamed into disorders of gut-brain interaction-such as irritable bowel syndrome and functional dyspepsia are highly prevalent conditions with bothersome abdominal symptoms in the absence of structural abnormalities. While traditionally considered as motility disorders or even psychosomatic conditions, our understanding of the pathophysiology has evolved significantly over the last two decades. Initial observations of subtle mucosal infiltration with immune cells, especially mast cells and eosinophils, are since recently being backed up by mechanistic evidence demonstrating increased release of nociceptive mediators by immune cells and the intestinal epithelium. These mediators can activate sensitised neurons leading to visceral hypersensitivity with bothersome symptoms. The interaction between immune activation and an impaired barrier function of the gut is most likely a bidirectional one with alterations in the microbiota, psychological stress and food components as upstream players in the pathophysiology. Only few immune-targeting treatments are currently available, but an improved understanding through a multidisciplinary scientific approach will hopefully identify novel, more precise treatment targets with ultimately better outcomes.

Prevalence of delayed gastric emptying in patients with gastroparesis-like symptoms

BACKGROUND

The European consensus defined gastroparesis as a condition characterised by delayed gastric emptying (GE) in the absence of mechanical obstruction, with a symptom pattern of predominant nausea and/or vomiting and overlapping postprandial distress syndrome (PDS). The distinction between patients with gastroparesis and those with functional dyspepsia (FD), another gastrointestinal condition characterised by predominant PDS or epigastric pain syndrome symptoms, is ongoing.

AIM

To investigate the extent that symptom patterns may differentiate gastroparesis from FD.

METHODS

This retrospective study included 637 patients from Leuven University Hospital in 2006-2021 who had upper gastrointestinal symptoms, underwent a GE test, and completed the Dyspepsia Symptom Severity (DSS) questionnaire. Patients were identified as with gastroparesis-like symptoms (GPLS; i.e., moderate to severe nausea with moderate to severe PDS) or FD symptoms (not fitting GPLS). We excluded patients aged <18 years, and those with diabetes, organic gastrointestinal disease or a history of abdominal surgeries. Demographic and clinical variables were compared.

RESULTS

Among 545 patients, 238 reported GPLS and 307 reported FD symptoms. Those with GPLS had a significantly higher prevalence of delayed GE (half emptying time (T1/2) ≥109 min) and lower body mass index than those with FD (33.2% vs 17.6%, p < 0.01; 19.9 vs 21.2, p < 0.01, respectively). Among GPLS patients, those with delayed GE had higher DSS than those without (13.0 vs 12.0, p < 0.01).

CONCLUSIONS

In tertiary care patients who reported gastroparesis or FD symptoms, the presence of delayed GE was associated with GPLS. In patients with GPLS, delayed GE was associated with higher symptom severity.

Targeting the altered duodenal microenvironment in functional dyspepsia

Duodenal micro-inflammation and microbial dysregulation are increasingly recognized to play an important role in functional dyspepsia (FD) pathophysiology, previously regarded as a purely functional disorder. With current therapeutic options contested through insufficient efficacy or unfavorable adverse effects profiles, novel treatments directed to duodenal alterations could result in superior symptom control in at least a subset of patients. Indeed, recent advances in FD research provided evidence for anti-inflammatory therapies to relieve gastroduodenal symptoms by reducing duodenal eosinophils or mast cells. In addition, restoring microbial homeostasis by probiotics proved to be successful in FD. As the exact mechanisms by which these novel pharmacological approaches result in clinical benefit often remain to be elucidated, future research should focus on how immune activation and dysbiosis translate into typical FD symptomatology.

Gastroparesis in geriatrics population: A United States population study

BACKGROUND

Older patients with upper gastrointestinal diseases may lack disease-specific symptoms that are required to make the correct diagnosis. This study aimed to compare the gastroparesis demographics, clinical presentation, and surgical management between the older adult and young populations.

METHODS

The National Inpatient Sample database was used between the years 2012 and 2014 with the primary diagnosis of gastroparesis. Patients were further divided based on their age into two groups: 70 years or older and younger than 70 years.

RESULTS

The older adults were more likely to have early satiety and bloating compared to younger population with an odds ratio (OR) = 3.79; 95% Confidence Interval (95%CI) 2.80- 5.11, p < 0.0001 and OR = 2.80, 95%CI 2.07-3.78, p<0.0001 respectively. Older adults had low odds of having nausea with vomiting (OR = 0.86, 95%CI 0.76-0.95, p = 0.003), or abdominal pain (OR = 0.56, 95%CI 0.50-0.63, p<0.0001).

CONCLUSIONS

Older adults had more early satiety and bloating, whereas younger patients had more nausea with vomiting and abdominal pain.

Unrecognized Functional Dyspepsia Among Those With Refractory Chronic Constipation: Analysis of a Tertiary Cohort

BACKGROUND AND AIMS

Patients with functional constipation (FC) are frequently dissatisfied with current treatment options which may be related to persistent, unaddressed symptoms. We hypothesized that refractory FC may actually represent functional dyspepsia (FD) overlap. Among adults presenting with refractory FC, we sought to (1) identify the prevalence of concurrent FD and (2) identify the symptoms and presentations most frequently associated with concurrent FD and FC.

METHODS

We assembled a retrospective cohort of 308 patients sequentially presenting to a tertiary neurogastroenterology clinic for evaluation of refractory FC, defined as having failed first-line therapy. Using Rome IV criteria, trained raters identified the presence and characteristics of concurrent FD in addition to demographics, presenting complaints, and psychological comorbidities.

RESULTS

Among 308 patients presenting with refractory FC (average of 3.0 ± 2.3 constipation treatments tried unsuccessfully), 119 (38.6%) had concurrent FD. Aside from meeting FD criteria, the presence of concurrent FD was associated with patient complaints of esophageal symptoms (Odds ratio = 3.1; 95% confidence interval, 1.80-5.42) and bloating and distension (Odds ratio = 2.67; 95% confidence interval, 1.50-4.89). Patients with concurrent FD were more likely to have a history of an eating disorder (21.0% vs 12.7%) and were also more likely to present with current avoidant/restrictive food intake disorder-related symptoms (31.9% vs 21.7%).

CONCLUSION

Almost 40% of adult patients referred for refractory FC met criteria for concurrent FD in a tertiary-level cohort. The presence of both FC and FD was associated with greater esophageal symptoms and bloating/distention. Determining presence of concurrent FD may represent an additional therapeutic opportunity in refractory patients who may attribute symptoms to FC alone.

Future of Brain-Gut Behavior Therapies: Mediators and Moderators

With growing evidence to support their efficacy, brain-gut behavior therapies are increasingly viewed as a key component to integrated care management of disorders of gut-brain interaction. However, the types of brain-gut behavior therapies differ in how and for whom they purportedly work. We provide a conceptual review of these brain-gut behavior therapies, with an emphasis on describing how (ie, mechanisms) and for whom (ie, moderators) they work as hypothesized and/or supported by evidence. Based on evidence to date, we recommend that brain-gut behavior therapies prioritize gastrointestinal-specific targets, such as gastrointestinal-specific anxiety.

Zhizhu Kuanzhong, a traditional Chinese medicine, alleviates gastric hypersensitivity and motor dysfunction on a rat model of functional dyspepsia

Ethnopharmacological relevance: Zhizhu Kuanzhong (ZZKZ) is a traditional Chinese medicine modified from classic formula Zhizhu decoction in "Synopsis of Golden Chamber" (Han Dynasty in the 3rd century) and the Zhizhu pill in "Differentiation on Endogenous" in Jin Dynasty (1,115-1,234). ZZKZ contains four botanical drugs, including Citrus × Aurantium L [Rutaceae; Aurantii Fructus Immaturus], Atractylodes Macrocephala Koidz. [Compositae; Rhizoma Atractylodis Macrocephalae], Bupleurum Chinense DC [Apiaceae; Radix Bupleuri Chinensis], and Crataegus Pinnatifida Bunge [Rosaceae; Fructus Crataegi Pinnatifidae], which have been widely used in clinical therapy for functional dyspepsia (FD). Aim of the study: This study aimed to evaluate the pharmacological effects and mechanisms of action of ZZKZ on gastric hypersensitivity and motor dysfunction in a rat model of FD. Materials and methods: FD was induced in Sprague-Dawley rats by neonatal gastric irritation with 0.1% iodoacetamide. The FD rats were treated with ZZKZ (0.5 g/kg, 1.0 g/kg, or 1.5 g/kg respectively) by gavage for 7 days, while domperidone (3 mg/kg) acted as treatment control. Body weight gain, food intake, gastric emptying, and intestinal propulsion were also measured. Ex vivo gastric smooth muscle activity recordings and greater splanchnic afferent (GSN) firing recordings were employed to evaluate gastric motility and sensation. Particularly, the role of 5-HT in the action of ZZKZ in improving gastric dysmotility and hypersensitivity was explored. Results: ZZKZ promoted weight gain, food intake, gastric emptying, and intestinal propulsion in FD rats. ZZKZ promoted spontaneous and ACh-induced contractions of gastric smooth muscle strips in FD rats, alleviated spontaneous activity, and chemical (acid perfusion) and mechanical (intragastric distension) stimulated GSN firing in FD rats. ZZKZ ameliorated gastric smooth muscle contraction and GSN firing induced by 5-HT in FD rats. ZZKZ stimulated the release of serum 5-HT, with reduced 5-HT3 receptor and increased 5-HT4 receptor mRNA expression in the guts of FD rats. Conclusion: This study demonstrated that ZZKZ improves FD-related gastric hypersensitivity and motor dysfunction and should be an effective compound for relieving FD symptoms. The gastric 5-HT system with lower 5-HT3 activity and increased 5-HT4 distribution is involved in the mechanisms of ZZKZ underlying the treatment of FD.

Alterations to the duodenal microbiota are linked to gastric emptying and symptoms in functional dyspepsia

OBJECTIVE

Functional dyspepsia (FD) is a complex disorder, with debilitating epigastric symptoms. Evidence suggests alterations in gastrointestinal (GI) motility, visceral hypersensitivity, permeability and low-level immune activation in the duodenum may play a role. However, we still have a relatively poor understanding of how these factors interact to precipitate the onset of FD symptoms which are frequently meal related. The duodenal microbiota, in combination with specific dietary substrates, may be important mediators in disease pathophysiology; however, these interlinked factors have not been thoroughly investigated in FD.

DESIGN

Eighty-six individuals (56 FD, 30 controls) undergoing endoscopy were consecutively recruited and underwent detailed clinical assessment, including upper GI symptoms, gastric emptying and dietary assessment. Duodenal biopsies were obtained aseptically, and the mucosa-associated microbiota (MAM) analysed via 16S rRNA gene amplicon sequencing.

RESULTS

The relative abundances of predominant members of the Firmicutes, Bacteroidota and Fusobacteriota phyla were linked to symptom burden in FD. Inverse relationships between the relative abundances of Streptococcus and Prevotella, and the relative abundance of Veillonella spp with gastric emptying time, were also observed. No significant differences in long-term nutrient intake or diet quality were found between FD and controls, and there appeared to be limited association between habitual diet and duodenal MAM profiles.

CONCLUSION

This study suggests a link between the duodenal MAM, gastric emptying and FD symptoms, and this is largely independent of long-term dietary intake.

British Society of Gastroenterology guidelines on the management of functional dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, affecting approximately 7% of individuals in the community, with most patients managed in primary care. The last British Society of Gastroenterology (BSG) guideline for the management of dyspepsia was published in 1996. In the interim, substantial advances have been made in understanding the complex pathophysiology of FD, and there has been a considerable amount of new evidence published concerning its diagnosis and classification, with the advent of the Rome IV criteria, and management. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based diagnosis and treatment of patients. The approach to investigating the patient presenting with dyspepsia is discussed, and efficacy of drugs in FD summarised based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of pairwise and network meta-analyses. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system. These provide both the strength of the recommendations and the overall quality of evidence. Finally, in this guideline, we consider novel treatments that are in development, as well as highlighting areas of unmet need and priorities for future research.

Smaller CO2 injection volume and lower gastric pressure induce bothersome symptoms in drug-resistant functional dyspepsia patients with less frequent belching

Background

The relationship between bothersome symptoms and gastric pressure or CO₂ injection volumes in drug-resistant functional dyspepsia (FD) patients remains unknown; therefore, this relationship was examined in drug-resistant FD and non-FD patients.

Methods

Thirty drug-resistant FD patients and 30 non-FD patients were recruited. Gastric pressure was assessed using an external pressure transducer, and the CO₂ injection volume was measured using an endoscopic CO₂-supplied device and flow meter. The following variables were examined: gastric pressure at baseline and gastric pressure and the CO₂ injection volume when patients initially felt abdominal tension and bothersome symptoms following the CO₂ injection. The relationship between belching and bothersome symptoms was also investigated.

Results

No significant differences were observed in basal gastric pressure between the groups. Initial and bothersome symptoms in the upper abdomen in drug-resistant FD patients developed at a significantly lower gastric pressure and significantly smaller CO₂ injection volume than in non-FD patients. The frequency of belching was significantly lower in the drug-resistant FD group than in the non-FD group.

Conclusion

Bothersome symptoms in drug-resistant FD patients develop at a lower gastric pressure and smaller CO₂ injection volume than in non-FD patients. These patients also had difficulties with belching.

Postprandial symptoms in patients with symptoms of gastroparesis: roles of gastric emptying and accommodation

Patients often are evaluated for gastroparesis because of symptoms occurring with meals. Gastric emptying scintigraphy (GES) is used for gastroparesis diagnosis, although results are not well correlated with gastroparesis symptoms. The aim of this study is to assess relationships between gastroparesis symptoms, gastric emptying (GE), and gastric accommodation (GA). Patients with symptoms of gastroparesis completed the Patient Assessment of Upper GI Symptoms (PAGI-SYM) and recorded symptoms during GES and water load satiety test (WLST), an indirect assessment for GA. A total of 109 patients with gastroparesis symptoms were assessed. Symptom severity increased after GES meal for stomach fullness, belching, nausea, abdominal burning, and abdominal pain. There was no difference in symptoms after meal between patients with delayed (n = 66) and normal (n = 42) GE. Diabetic patients (n = 26) had greater gastric retention than idiopathic patients (n = 78), but idiopathic patients had greater postprandial nausea, stomach fullness, and abdominal pain. Water consumed during WLST averaged 421 ± 245 mL. Idiopathic patients had greater nausea scores during WLST than diabetic patients. In comparison to those with normal water consumption (≥238 mL; n = 80), patients with impaired water ingestion (<238 mL; n = 26) had increased stomach fullness, early satiety, postprandial fullness, and loss of appetite on PAGI-SYM. Patients with delayed and normal GE had similar symptom profiles during GES and WLST. Idiopathic patients had less gastric retention but more symptoms after GES meal and after WLST compared with diabetic patients. Patients with impaired water consumption during WLST had increased symptoms by PAGI-SYM. These data suggest that impaired GA, rather than GE, may be important in explaining postprandial symptoms in patients with symptoms of gastroparesis.NEW & NOTEWORTHY Patients with delayed and normal gastric emptying (GE) had similar symptom profiles during gastric emptying scintigraphy (GES). Idiopathic patients with symptoms of gastroparesis had less gastric retention by GES; but more symptoms after GES meal and after water load satiety test (WLST) compared with diabetic patients. In patients with symptoms of gastroparesis, symptoms after WLST increased with decreasing water consumption. Early satiety and loss of appetite were associated with decreased water consumption during WLST. Thus, impaired accommodation and perhaps visceral hypersensitivity are important in explaining postprandial symptoms in gastroparesis.

Altered Vagal Signaling and Its Pathophysiological Roles in Functional Dyspepsia

The vagus nerve is crucial in the bidirectional communication between the gut and the brain. It is involved in the modulation of a variety of gut and brain functions. Human studies indicate that the descending vagal signaling from the brain is impaired in functional dyspepsia. Growing evidence indicate that the vagal signaling from gut to brain may also be altered, due to the alteration of a variety of gut signals identified in this disorder. The pathophysiological roles of vagal signaling in functional dyspepsia is still largely unknown, although some studies suggested it may contribute to reduced food intake and gastric motility, increased psychological disorders and pain sensation, nausea and vomiting. Understanding the alteration in vagal signaling and its pathophysiological roles in functional dyspepsia may provide information for new potential therapeutic treatments of this disorder. In this review, we summarize and speculate possible alterations in vagal gut-to-brain and brain-to-gut signaling and the potential pathophysiological roles in functional dyspepsia.

Potential Mechanisms of Acupuncture for Functional Dyspepsia Based on Pathophysiology

Functional dyspepsia (FD), a common disorder of gastrointestinal function, originated from the gastroduodenum. Although the therapeutic effect of acupuncture has been investigated by various high-quality randomized controlled trials, the potential mechanisms showed obvious heterogeneity. This review summarized the potential mechanisms of acupuncture on FD in order to guide for future laboratory and clinical studies. Here, we argued that the primary cause of FD was gastroduodenal low-grade inflammation and acid exposure, which impaired mucosal integrity, caused brain-gut axis dysfunction, and impaired brain network connectivity, all of which generated various symptom patterns. Overall the clinical studies indicated that acupuncture was a promising treatment to alleviate symptoms in FD patients, whose efficacy was influenced by acupoints and individual variance. Mechanistically, studies with animal models of FD and patients have shown that acupuncture, a non-invasive strategy for nerve stimulation, may have the potential to control intestinal inflammation and suppress acid-secretion via different somatic autonomic reflex pathways, regulate the brain-gut axis through intestinal microbiota, and has the potential to ameliorate FD-symptoms. The cumulative evidence demonstrated that acupuncture is a promising treatment to alleviate symptoms of FD patients.

Prevalence, symptoms and risk factor profile of rumination syndrome and functional dyspepsia: a population-based study

BACKGROUND

Rumination syndrome is a functional gastroduodenal disorder characterised by effortless regurgitation of recently ingested food. Emerging evidence reports duodenal eosinophilic inflammation in a subset, suggesting a shared pathophysiology with functional dyspepsia (FD).

AIM

To assess the clinical features of rumination syndrome and FD in a community-based study.

METHODS

We mailed a survey assessing gastrointestinal symptoms, diet and psychological symptoms to 9835 residents of Olmsted County, MN, USA in 2017-2018; diagnostic codes were obtained from linked clinical records. The two disorders were assessed as mutually exclusive in 'pure' forms with a separate overlap group, all compared to a control group not meeting criteria for either. Prevalence of associations, and univariate and independent associations with predictors were assessed by logistic regression.

RESULTS

Prevalence of rumination syndrome and FD were 5.8% and 7.1%, respectively; the overlap was 3.83-times more likely than expected by chance. Independent predictors for rumination (odds ratio (OR), 95% confidence interval (CI)) were female gender (1.79, 1.21-2.63), smoking (1.89, 1.28-2.78), gluten-free diet (1.58, 1.14-2.19), allergic rhinitis (1.45, 1.01-2.08) and depression (1.10, 1.05-1.16). FD was independently associated with female gender, depression, non-coeliac wheat sensitivity, migraine, irritable bowel syndrome and somatic symptoms. A similar reported efficacy (≥54%) of low fat or dairy-free diets was found with both disorders (P = 0.53 and P = 1.00, respectively). The strongest independent associations with overlapping FD and rumination syndrome were a history of rheumatoid arthritis (3.93, 1.28-12.06) and asthma (3.02, 1.44-6.34).

CONCLUSION

Rumination syndrome overlaps with FD with a shared risk factor profile, suggesting a common pathophysiology.

A Preclinical Feasibility Study of Endoscopic Barostat: A Possible Diagnostic Tool for Visceral Hypersensitivity in Functional Dyspepsia

INTRODUCTION

Diagnosing functional dyspepsia requires excluding organic disease and gastrointestinal function evaluation; however, there are no modalities to evaluate these simultaneously. This preclinical study examined the possibility of an endoscopic barostat.

METHODS

Ultrathin endoscopy and our newly developed pressure-regulated endoscopic insufflator, which insufflates the gastrointestinal tract until the preset pressure is achieved, were used. The actual intragastric pressure was measured using an optical fiber manometer placed in the stomach. Experiment-1: in an ex vivo experiment, we insufflated the isolated stomach and verified whether the intragastric pressure reached the preset pressure. Experiment-2: we inserted the endoscope orally in a porcine stomach, insufflated the stomach, and verified whether the intragastric pressure reached the preset pressure. Finally, we insufflated the stomach at a random pressure to verify the functional tests for proof-of-concept.

RESULTS

Experiment-1: the intragastric pressure reached the preset pressure. After reaching the plateau, the pressure remained stable at the preset pressure (Huber M value: 1.015, regression line: 0.988, 95% confidence interval [CI]: 0.994-0.994). Experiment-2: the intragastric pressure reached the preset pressure. After reaching the plateau, the pressure remained stable at the preset pressure (Huber M value: 1.018, regression line: 0.971, 95% CI: 0.985-0.986). At randomly preset pressures, the transendoscopic theoretical intragastric pressure detected by using the insufflator was correlated with the actual pressure measured by using the pressure manometer.

CONCLUSIONS

This proof-of-concept study shows that a pressure-regulated endoscopic insufflator provides stable intragastric pressure at the preset level, with the potential of an endoscopic barostat to assess the visceral hypersensitivity related to functional dyspepsia.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

METHODS

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

RESULTS

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long-term prognosis and life expectancy are favorable.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

The Usefulness of Symptom-based Subtypes of Functional Dyspepsia for Predicting Underlying Pathophysiologic Mechanisms and Choosing Appropriate Therapeutic Agents

Functional dyspepsia (FD) is considered to be a heterogeneous disorder with different pathophysiological mechanisms or pathogenetic factors. In addition to traditional mechanisms, novel concepts regarding pathophysiologic mechanisms of FD have been proposed. Candidates of therapeutic agents based on novel concepts have also been suggested. FD is a symptom complex and currently diagnosed by symptom-based Rome criteria. In the Rome criteria, symptom-based subtypes of FD including postprandial distress syndrome and epigastric pain syndrome are recommended to be used, based on the assumption that each subtype is more homogenous in terms of underlying pathophysiologic mechanisms than FD as a whole. In this review, the usefulness of symptombased subtypes of FD for predicting underlying pathophysiologic mechanisms and choosing appropriate therapeutic agents was evaluated. Although several classic pathophysiologic mechanisms are suggested to be associated with individual dyspeptic symptoms, symptom-based subtypes of FD are not specific for a certain pathogenetic factor or pathophysiologic mechanism, and may be frequently associated with multiple pathophysiologic abnormalities. Novel concepts on the pathophysiology of FD show complex interactions between pathophysiologic mechanisms and pathogenetic factors, and prediction of underlying mechanisms of individual patients simply by the symptom pattern or symptom-based subtypes may not be accurate in a considerable proportion of cases. Therefore, subtyping by the Rome criteria appears to have limited value to guide therapeutic strategy, suggesting that the addition of objective parameters or subclassification reflecting physiologic or pathologic tests may be necessary for the targeted therapeutic approaches, particularly when therapeutic agents targeting novel mechanisms are available.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

Background

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

Methods

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

Results

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long‐term prognosis and life expectancy are favorable.

Conclusions and Inferences

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

Current knowledge

Functional dyspepsia is one of the most common conditions encountered in clinical practice.

There is a lack of guidance for clinicians in guiding diagnosis and treatment of this prevalent condition.

No treatments are currently approved for the treatment of functional dyspepsia in Europe.

What is new here

A Delphi panel consisting of 41 experts from 22 European countries established the level of consensus on 87 statements regarding functional dyspepsia.

The statements reaching consensus serve to guide clinicians in recognizing, diagnosing and treating FD in clinical practice.

Endoscopy is mandatory for establishing a firm diagnosis of functional dyspepsia D, but in primary care patients without alarm symptoms or risk factors can be managed without endoscopy.

Helicobacter pylori status should be determined in every patient with dyspeptic symptoms and H. Pylori positive patients should receive eradication therapy.

Proton pump inhibitor‐therapy is considered an effective therapy for FD, but no other treatment approach reached consensus support.

New endoscopic method for gastric hypersensitivity testing: Pilot study

Background and Aim

Although one of the causes of dyspeptic symptoms in functional dyspepsia patients is gastric hypersensitivity, there is currently no routine endoscopic gastric hypersensitivity test. We developed a new endoscopic method for gastric hypersensitivity testing. The aim of the present study was to investigate whether this method is useful for evaluating gastric hypersensitivity in drug‐resistant functional dyspepsia patients who were strongly suspected of having gastric hypersensitivity.

Methods

Twenty‐seven drug‐resistant functional dyspepsia patients and 27 nonfunctional dyspepsia patients were recruited. Gastric pressure was assessed using an external pressure transducer, and the CO₂ insufflation volume was measured using an endoscopic CO₂‐supplied device and flow meter. The following variables were examined: gastric pressure at baseline and gastric pressure, the CO₂ insufflation volume, and compliance of the stomach when patients initially felt abdominal tension following CO₂ insufflation.

Results

No significant differences were observed in baseline gastric pressure or compliance of the stomach between the groups. Drug‐resistant functional dyspepsia patients had a significantly smaller CO₂ insufflation volume and lower gastric pressure when symptoms developed than nonfunctional dyspepsia patients. Based on a cutoff value of 1.25 L by receiver operating characteristic curves, sensitivity and specificity for gastric pressure were 85.0 and 96.3%, respectively. Similarly, based on a cutoff value of 12.7 mmHg, sensitivity and specificity for the CO₂ insufflation volume were 81.5 and 81.5%, respectively.

Conclusion

This endoscopic gastric hypersensitivity testing is a useful tool for evaluating the presence of gastric hypersensitivity.

The water load test in school children and adolescents with functional gastrointestinal disorders

BACKGROUND/AIMS

We hypothesize that patients with functional gastrointestinal disorders (FGID) drink less water volume than healthy subjects during water load test. We evaluated and compared the water load test in students with and without FGID using the Rome III questionnaire.

METHODS

We performed the water load test in 142 students from two schools in Colombia. Students were diagnosed using the Spanish version of the Rome III questionnaire. Students drank water ad libitum for 3 min or until pain, satiety, or vomiting occurred. We correlated anthropometric variables with water volumes drunk. We recorded symptoms like pain and nausea, before and after the water load test.

RESULTS

We evaluated 142 students, with a mean age of 12.1 ± 0.2 years and 59.9% girls. Mean water volume drunk was 459 ± 22 mL. There was no significant difference between water volume drunk by students with and without FGID (466 ± 36 vs. 453 ± 27 mL, p = 0.108). We found a significant correlation between water volume drunk and gender, age, weight, height, and body mass index.

CONCLUSIONS

Students with and without FGID ingest similar volumes of water. Test adverse effects are minimal, and the test is safe to perform and well tolerated.

Reference values for the water load test in healthy school children and adolescents

BACKGROUND AND STUDY AIM

The water load test (WLT) is an easy and cheap tool, useful in evaluating gastric accommodation and visceral hypersensitivity. This test can be used in diagnosing functional gastrointestinal disorders, like functional dyspepsia. Our main aim was to propose reference values for the WLT. Our secondary aim was to correlate the water volume drunk with the students' gender, age, and anthropometric measures.

PATIENTS AND METHODS

We performed the WLT in students aged 8 to 17 years. Students drank water ad libitum for 3 minutes or until pain, satiety or vomiting occurred. We correlated anthropometric variables with water volumes drunk. Upper and lower limit for the maximum tolerated volume were calculated as the 5th and 95th percentile. Pain and nausea were recorded before and after the test.

RESULTS

We evaluated 99 students, with a median age (inter quartile range) of 11 years 10-13 years) and 55.6 % were girls. Median water volume drank was 380 ml (190-540 ml). Boys (523 ml, interquartile range : 275-760 ml) drank more water than girls (380 ml, interquartile range : 190-570 ml) (p = 0.016). There was a significant correlation between water volume drank and students´ age, weight, height, and body mass index. Of the students that completed the WLT, 22.2 % had nausea and 30.3 % had mild abdominal pain after the test.

CONCLUSIONS

We proposed reference values for the WLT in children aged 8 to 17 years. Adverse effects are minimal, it is safe to perform, and well tolerated.

Recent Advances in the Definition and Management of Functional Dyspepsia

In 2016, the Rome criteria were updated as Rome IV, and only minor changes were introduced for functional dyspepsia (FD). The major symptoms of FD now include not only postprandial fullness, but also epigastric pain and burning, and early satiation at above the "bothersome" level. Investigations into the effect of meal ingestion on symptom generation have indicated that not only postprandial fullness and early satiety but also epigastric pain and burning sensation and nausea (not vomiting) may increase after meals. Helicobacter pylori infection is considered to be the cause of dyspepsia if successful eradication leads to sustained resolution of symptoms for more than 6 months, and such a condition has been termed H. pylori-associated dyspepsia. Prompt esophagogastroduodenoscopy and H. pylori "test and treat" may be beneficial, especially in regions with a high prevalence of gastric cancer, such as east Asia. In terms of treatment, acotiamide, tandospirone, and rikkunshito are newly listed in Rome IV as treatment options for FD. Clinical studies in the field of FD should be strictly based on the Rome IV criteria until the next Rome V is published in 2026.

Association between gastrointestinal symptoms and depression among older adults in Taiwan: A cross-sectional study

BACKGROUND

Older adults with depression more frequently experience somatic and gastrointestinal (GI) problems compared with people without depression and younger adults with depression. However, whether GI symptoms are predictive of elevated rates of depression among older adults is unclear.

METHODS

We enrolled 106 older adults (>60 years old); 69 had late-life depression (LLD), and 37 were controls. All participants gave ratings on the Gastrointestinal Symptom Rating Scale (GSRS) and Hamilton Depression Rating Scale. Food consumption was assessed using a food frequency questionnaire, and a Mediterranean diet score was used as a covariate.

RESULTS

Compared with the controls, patients with LLD reported higher levels of depressive and GI symptoms and reported more reflux, abdominal pain, and dyspepsia symptoms, and these symptoms were correlated with Hamilton Depression Rating Scale scores (GSRS total: β = 0.47; reflux: β = 1.47; abdominal pain: β = 1.98; dyspepsia: β = 1.02; all p < 0.01). After demographic variables and Mediterranean diet score were controlled for, a logistic regression analysis indicated that total GSRS score was an independent determinant of LLD (odds ratio: 1.20, 95% CI: 1.04-1.38). Moreover, a stratified analysis by depression severity indicated that higher total GSRS score may contribute to greater depression severity (odds ratio: 1.25, 95% CI: 1.04-1.52).

CONCLUSION

We provide evidence that GI symptoms are associated with depressive symptoms among patients with LLD. Older people with more specific GI symptoms, such as reflux, abdominal pain, and dyspepsia, are potentially at greater risk of having LLD.

Functional dyspepsia in children: A study of pathophysiological factors

BACKGROUND AND AIM

Functional dyspepsia (FD) is common in children, and treatment targeted towards the altered pathophysiology can improve outcome. We evaluated FD children for abnormality of gastric accommodation and emptying, psychological stressors (PS), Helicobacter pylori (HP) infection, and post-infectious FD.

METHODS

Diagnosis of FD was based on ROME III criteria. Clinical evaluation including dyspeptic symptom scoring and assessment for PS was performed. Satiety drink test for gastric accommodation, gastroscopy with biopsy for HP infection, and solid meal gastric emptying were performed. Sixty-seven healthy children were enrolled for assessing PS and satiety drink test.

RESULTS

Fifty-five FD children (33 boys, age 12 [6-18] years) with symptoms for 4 (2-48) months and dyspeptic score of 5 (1-13) were enrolled. PS were more common in FD than in controls (46/55 vs 9/67; P < 0.001). Median satiety drink volume was 360 mL (180-1320 mL); no patients had satiety drink volume of < 5th centile of healthy children. The frequency (98% vs 85%; P = 0.01) and severity (65 [10-175] vs 50 [5-130]; P < 0.001) of postprandial symptoms were higher in FD than in controls. Of the postprandial symptoms, pain (20.3% vs 0%; P = 0.000) was present only in FD. Delayed gastric emptying was present in 6.5%, HP infection in 11%, and post-infectious FD in 13% cases. Etiological factor was identified in 87% children, with 20% having multiple factors.

CONCLUSIONS

Abnormality of gastric sensorimotor function is seen in one-fourth of FD cases. HP infection and post-infectious FD are present in 11% and 13% cases, respectively.

Efficacy and safety of Si-Jun-Zi-Tang-based therapies for functional (non-ulcer) dyspepsia: a meta-analysis of randomized controlled trials

BACKGROUND

The traditional Chinese medicine formula Si-Jun-Zi-Tang (SJZT) has a long history of application in the treatment of functional dyspepsia (non-ulcer dyspepsia, FD)-like symptoms. SJZT-based therapies have been claimed to be beneficial in managing FD. This study aimed to assess the efficacy and safety of SJZT-based therapies in treating FD by meta-analysis.

METHODS

Systematic searches for RCTs were conducted in seven databases (up to February 2019) without language restrictions. Data were analyzed using Cochrane RevMan software version 5.3.0 and Stata software version 13.1, and reported as relative risk (RR) or odds ratio (OR) with 95% confidence intervals (CIs). The primary outcome was response rate and the secondary outcomes were gastric emptying, quality of life, adverse effects and relapse rate. The quality of evidence was evaluated according to criteria from the Cochrane risk of bias.

RESULTS

A total of 341 potentially relevant publications were identified, and 12 RCTs were eligible for inclusion. For the response rate, there was a statically significant benefit in favor of SJZT-based therapies (RR = 1.23; 95% CI 1.17 to 1.30). However, the benefit was limited to modified SJZT (MSJZT). The relapse rate of FD patients received SJZT-based therapies was lower than that of patients who received conventional medicines (OR = 0.23; 95% CI 0.10 to 0.51). No SJZT-based therapies-related adverse effect was reported.

CONCLUSION

SJZT-based prescriptions may be effective in treating FD and no serious side-effects were identified, but the effect on response rate appeared to be limited to MSJZT. The results should be interpreted with caution as all the included studies were considered at a high risk of bias. Standardized, large-scale and strictly designed RCTs are needed to further validate the benefits of SJZT-based therapies for FD management.

TRIAL REGISTRATION

Systematic review registration: [PROSPERO registration: CRD42019139136 ].