The role of psychosocial factors and psychiatric disorders in functional dyspepsia

Bioinformatics and LC-QTOF-MS based discovery of pharmacodynamic and Q-markers of Pitongshu against functional dyspepsia

ETHNOPHARMACOLOGICAL RELEVANCE

Pitongshu (PTS) is a clinically effective empirical formula for the treatment of FD. The efficacy and safety of PTS have been demonstrated in randomized, controlled, double-blind trials, but there is a lack of understanding of the systematic evaluation of the efficacy of PTS and its material basis.

OBJECTIVE

To investigate the efficacy of PTS in Functional dyspepsia (FD) mice and possible Q-markers.

METHOD

In this study, we used "irregular feeding + chronic unpredictable chronic stimulation" to establish a mice model of FD with hepatogastric disharmony. The efficacy of PTS was assessed from hair condition, behavioral, pain, gastrointestinal function, and serum 5-HT, GAS, MTL levels in mice by instillation of different doses of PTS. In addition, the composition of drugs in blood was analyzed by LC-QTOF-MS and potential Q-markers were selected by combining network pharmacology, molecular docking and actual content.

RESULT

Our study showed that different doses of PTS increased pain threshold and writhing latency, decreased the number of writhings, increased gastric emptying rate and small intestinal propulsion rate, decreased total acidity of gastric contents and gastric acid secretion, and increased serum levels of 5-HT, GAS, and MTL in mice to different degrees. Enrichment analysis showed that PTS may be anti-FD through multiple pathways such as Serotonergic synapse, thyroid hormone signaling pathway, cholinergic synapse, and dopaminergic synapse. In addition, potential active ingredient substances were explored by LC-QTOF-MS combined with bioinformatics. Combined with the actual contentselected six constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol, possible as Q-markers.

CONCLUSION

PTS may exert its anti-FD effects through multi-component, multi-target and multi-pathway". Constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol may be the Q-markers of its anti-FD effects.

Effectiveness and safety of Chaihu-Shugan-San for treating depression based on clinical cases: An updated systematic review and meta-analysis

BACKGROUND

Chaihu-Shugan-San (CSS), a Traditional Chinese Medicine formula, has been widely used for treating depression since the Ming Dynasty, as recorded in Jingyue Quanshu, but its effectiveness and safety lack comprehensive and objective evaluation. Based on our meta-analysis, we aimed to adequately evaluate the efficacy and risk of CSS by considering the latest clinical literature.

METHODS

Multiple databases, including PubMed, Embase, Web of Science, SinoMed, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang, were used to collect clinical data. The quality of the included clinical studies was assessed using the Cochrane Risk of Bias Tool, and the data were meta-analyzed using Review Manager 5.0 and Stata 17. The data were obtained from a genome-wide association study, and Mendelian randomization (MR) was performed using R Software 4.3.2 with the TwoSampleMR and MR Pleiotropy RESidual Sum and Outlier packages.

RESULTS

A total of 15 studies with 1034 patients and 6 antidepressant drugs were included in this work. Meta-analyses revealed that drug combinations of CSS and antidepressants significantly improved depressive symptoms (weighted mean difference = -4.21; 95% confidence interval [CI]: -5.62--2.81), increased the effective rate (odds ratio [OR] = 3.82; 95% CI: 2.44-6.83), and reduced side effects (OR = -3.55; 95% CI: -5.66--1.43) compared with antidepressant monotherapy. Additionally, compared with antidepressant monotherapy, CSS alone exhibited fewer side effects (95% CI:-9.25--6.95). Like antidepressants, CSS also improved depressive symptoms (weighted mean difference = -0.05; 95% CI: -0.63--0.52) and increased the effective rate (OR = 1.07; 95% CI: 0.52-2.20). Additionally, MR was used to evaluate the safety of traditional antidepressants, as there was a causal association between amitriptyline and body mass index.

CONCLUSION

This analysis demonstrated that compared with traditional antidepressants, CSS combined with antidepressants was more effective and safer for treating depressed patients. MR showed that a causal relationship may exist between amitriptyline and body mass index. Therefore, clinicians should carefully consider the advantages and potential drawbacks of Traditional Chinese Medicine and classic drugs to serve patients better.

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.

Epidemiology of functional dyspepsia and gastroparesis as diagnosed in Flemish-Belgian primary care: A registry-based study from the Intego database

BACKGROUND

Dyspepsia is a prevalent condition in the general population. Besides organic causes, the differential diagnosis of dyspepsia includes functional dyspepsia (FD) and gastroparesis (GP) which share similar pathophysiological mechanisms and clinical presentation. So far, no study investigated the prevalence of FD and GP in a primary care in Belgium.

METHODS

Data were obtained from Intego, a Flemish-Belgian general practice-based morbidity registration network. From 586,164 patients between 2000 and 2021, we selected patients with ICD-10 code for FD and GP. Patients with organic gastrointestinal diseases were excluded. We determined demographics and comorbidities of FD/GP. For prevalence and incidence calculation, we included those who consulted their general practitioners at least once in the given year. Pair-wise comparison was conducted to access the impact of comorbidities on risk of FD/GP.

KEY RESULTS

Between 2011 and 2021, the prevalence of FD/GP ranged from 1.03% to 1.21%. The incidence of FD/GP ranged from 109 to 142 per 100,000 adults. In total 5242 cases of FD/GP were identified. These cases shared commonly coexisting diagnoses of gastroesophageal reflux disease (18.8%), irritable bowel syndrome (17.1%), and chronic constipation (18.7%). Patients with somatization/anxiety/depression had significantly higher risk of FD/GP, compared to the control (OR 1.38, 95% CI 1.19-1.61, p < 0.01).

CONCLUSIONS AND INFERENCES

The prevalence (1.03%-1.21%) and incidence (109-142/100,000) of FD/GP in primary care over last decade appear to conflict with epidemiological research in the general population. The discrepancies suggest a potential lack of awareness of FD and GP among physicians and/or patients in Flemish-Belgium.

Application and value of anxiety and depression scale in patients with functional dyspepsia

BACKGROUND

Patients with functional dyspepsia (FD) cannot be assessed for their mental health using a suitable and practical measure. The purpose of the study is to investigate the usefulness of several anxiety and depression scales in patients with FD, offering recommendations for clinical identification and therapy.

METHODS

From September 2021 to September 2022, patients were sought and selected. The psychological symptoms were assessed using ten depression or anxiety questionnaires. The receiver operating characteristic (ROC) curve, Spearman analysis, Pearson correlation analysis, and single factor analysis were applied.

RESULTS

Prospective analysis was performed on 142 healthy individuals and 113 patients with FD. In the case group, anxiety and depression symptoms were more common than in the control group, and the 10 scales showed strong validity and reliability. HAMD had the strongest connection with the PHQ-9 score on the depression scale (0.83). The score correlation between SAS and HAMA on the anxiety analysis scale was the greatest at 0.77. The PHQ-9, SAS, HAMD, and HAMA measures performed exceptionally well in detecting FD with anxiety or depression symptoms (AUC = 0.72, 0.70, 0.70, 0.77, and 0.77, respectively).

CONCLUSIONS

PHQ-9, SAS, HAMD, and HAMA scales have good application performance in FD patients. They can assist gastroenterologists in evaluating anxiety and depression symptoms, and provide reference and guidance for subsequent treatment.

Effect of Chaihu-Shugan-San on functional dyspepsia and gut microbiota: A randomized, double-blind, placebo-controlled trial

ETHNOPHARMACOLOGICAL RELEVANCE

Chaihu-Shugan-San (CSS) is a classic traditional Chinese medicine (TCM) formula from the Ming Dynasty "Jingyue's Complete Works". In China, it is prevalent for the treatment of a wide range of ailments, with a particular emphasis on functional gastrointestinal disorders (FGIDs). Clinical evidence suggests that CSS has been found to be a highly effective therapeutic approach for the treatment of Functional Dyspepsia (FD), however, there is a limited amount of high-quality clinical evidence, particularly randomized, double-blind, placebo-controlled trials to support this claim.

AIM OF THE STUDY

To evaluate the therapeutic efficacy of Chaihu-Shugan-San (CSS) for treating functional dyspepsia (FD) by comparing it to placebos, as well as to investigate the impact of CSS on the gut microbiota in individuals diagnosed with FD.

MATERIALS AND METHODS

This was a randomized double-blind, placebo-controlled clinical trial implemented at Shuguang Hospital in Shanghai. Between May 2021 and December 2022, 94 participants satisfying the Rome IV diagnostic criteria for FD were enrolled. They were assigned randomly to either the CSS group or the placebo group, with an equal allocation ratio of 1:1. Patients in both groups received the intervention for four weeks. The primary outcome was the dyspepsia symptom scores evaluated by using single dyspepsia symptom scale (SDS) after four weeks of treatment. The secondary outcomes were the solid gastric empties rate measured by a barium strip method, Hamilton anxiety scale (HAMA), Hamilton depression scale (HAMD), and Functional dyspepsia Quality of life scale (FDDQL). In addition, after unblinding, 30 patients in the CSS group were randomly selected and divided into before and after treatment of the FD groups (FD1, FD2), and 30 healthy participants were selected as healthy control group (HC), and the gut microbiota was analyzed by 16S rRNA sequencing.

RESULTS

After four weeks of treatment, the SDS score exhibited a significant improvement in the CSS group compared to the placebo group (t = 4.882; P ＜0.001). The difference in barium strip gastric emptying rate in the CSS group showed a significant ascent compared to the control group (P < 0.01). The HAMA, HAMD, and FDDQL scores in the CSS group showed a statistically significant increase compared to the control group (all P < 0.01). The results of 16S rRNA sequencing revealed that FD patients had less diverse and abundant microbiota than the healthy people. Additionally, the application of CSS resulted in the modulation of certain bacterial populations, leading to both up-regulation and down-regulation of their quantities.

CONCLUSIONS

These findings suggested that CSS is more effective compared to a placebo in treating FD, relieves anxiety and depression, increases gastric emptying rate in FD patients, and that CSS also affects the bacterial community structure in FD patients.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100045793. Registered 25 Mach 2021.

Comparing the efficacy of duloxetine and nortriptyline in alleviating the symptoms of functional dyspepsia - a randomized clinical trial

Aim

To compare the efficacy of Duloxetine and Nortriptyline in alleviating the symptoms of severity, anxiety, depression and quality of life in patients with functional dyspepsia (FD).

Material and method

We conducted a single-blinded 3-month trial of Duloxetine 20-30 mg daily in 20 patients and Nortriptyline 25 mg daily in 25 FD patients. The primary outcome measure was the severity of FD symptoms by Gastrointestinal symptoms rating scale. Secondary measures included Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, and Nepean Dyspepsia Index. the patients were measured in 3 stages.

Results

45 patients with FD with a mean age of 37.18 ± 10.62 years participated in the study. The severity of symptoms was significantly lower in the Nortriptyline group than in the Duloxetine group after three months (p = 0.031). The level of anxiety (p = 0.049), depression (p = 0.045) and quality of life (p = 0.046) improved significantly after three months in the Duloxetine group compared to Nortriptyline. Mediation analysis using linear regression revealed a significant mediator role for anxiety. This mediation analysis revealed a 21.13% reduction in anxiety in the Duloxetine group.

Conclusion

While both medications demonstrated efficacy, Nortriptyline appeared to be superior in symptom reduction. Duloxetine exhibited more advantages compared to Nortriptyline in addressing anxiety and depression and enhancing the overall quality of life. Also, Duloxetine may have a noteworthy impact, contributing to a 20% reduction in FD symptoms by lowering anxiety levels.

Clinical trial registration

https://en.irct.ir/trial/65512.

Research Progress for Probiotics Regulating Intestinal Flora to Improve Functional Dyspepsia: A Review

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. The pathophysiology remains poorly understood; however, alterations in the small intestinal microbiome have been observed. Current treatments for FD with drugs are limited, and there are certain safety problems. A class of active probiotic bacteria can control gastrointestinal homeostasis, nutritional digestion and absorption, and the energy balance when taken in certain dosages. Probiotics play many roles in maintaining intestinal microecological balance, improving the intestinal barrier function, and regulating the immune response. The presence and composition of intestinal microorganisms play a vital role in the onset and progression of FD and serve as a critical factor for both regulation and potential intervention regarding the management of this condition. Thus, there are potential advantages to alleviating FD by regulating the intestinal flora using probiotics, targeting intestinal microorganisms. This review summarizes the research progress of probiotics regarding improving FD by regulating intestinal flora and provides a reference basis for probiotics to improve FD.

Exercise is inversely associated with functional dyspepsia among a sample of Chinese male armed police recruits

BACKGROUND

There is no study evaluating the association between exercise and functional dyspepsia (FD) based on the Rome IV criteria. We aimed to investigate the prevalence of FD and evaluate the association between exercise and FD based on Rome IV criteria among a sample of Chinese armed police recruits.

METHODS

An on-site questionnaire survey on FD among a sample of Chinese armed police recruits was conducted based on the Rome IV criteria in 2021. Potential confounders included age, body mass index (BMI), race, marriage, education, smoking, and drinking variables were adjusted.

RESULTS

A total of 2594 recruits were enrolled, including 46 FD participants and 2548 non-FD participants. In the model adjusted for all demographic variables among participants excluding irritable bowel syndrome (IBS) and functional constipation (FC), compared with no exercise participants, 1 h < each exercise time ≤ 2 h (OR = 0.15, 95% CI: 0.03-0.77, P = 0.0230) was inversely associated with FD and compared with no exercise participants, mild exercise (OR = 0.09, 95% CI: 0.01-0.71, P = 0.0220) was significantly inversely associated with FD.

CONCLUSIONS

The incidence rate of FD in this sample Chinese armed police recruits was 1.77%, and 1 h < each exercise time ≤ 2 h and mild intensity exercise were independently inversely associated with FD. However, the causal relationship needs to be verified by further randomized controlled trials.

Brain activity in response to food images in patients with irritable bowel syndrome and functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are caused and exacerbated by consumption of fatty foods. However, no study has evaluated brain activity in response to food images in patients with disorders of gut-brain interaction (DGBI). This study aimed to compare food preference and brain activity when viewing food images between patients with DGBI and healthy controls.

METHODS

FD and IBS were diagnosed using the ROME IV criteria. Food preference was assessed using a visual analog scale (VAS). Brain activity in the prefrontal cortex (PFC) in response to food images was investigated using functional near-infrared spectroscopy (fNIRS).

RESULTS

Forty-one patients were enrolled, including 25 with DGBI. The mean VAS scores for all foods (controls vs. FD vs. IBS: 69.1 ± 3.3 vs. 54.8 ± 3.8 vs. 62.8 ± 3.7, p = 0.02), including fatty foods (78.1 ± 5.4 vs. 43.4 ± 6.3 vs. 64.7 ± 6.1, p < 0.01), were the lowest in patients with FD among all groups. Patients with FD had significantly higher brain activity in the left PFC than those with IBS and healthy controls (mean z-scores in controls vs. FD vs. IBS: - 0.077 ± 0.03 vs. 0.125 ± 0.04 vs. - 0.002 ± 0.03, p < 0.001).

CONCLUSIONS

Patients with DGBI, particularly those with FD, disliked fatty foods. The brain activity in patients with DGBI differed from that in healthy controls. Increased activity in the PFC of patients with FD was confirmed.

Association between dietary factors, symptoms, and psychological factors in adults with dyspepsia: A cross-sectional study

BACKGROUND

Evidence-based dietary management approaches for symptoms of dyspepsia are lacking. This study aimed to compare dietary factors, symptoms, quality of life (QOL) and salivary cortisol in dyspepsia participants and healthy controls.

METHODS

A cross-sectional survey was completed by adults with dyspepsia (n = 121) meeting Rome IV criteria and healthy controls (n = 52). Outcome measures included self-reported questionnaires about dietary habits, triggers, restrictions, dietary management approaches, nutritional intake, psychological variables, QOL, gastrointestinal symptoms, and optional cortisol awakening response (CAR) via saliva samples. Data were analyzed using Chi-square or Mann-Whitney U. Cortisol awakening response data was analyzed using moderated regression controlling for age, gender and distress.

KEY RESULTS

Fermentable carbohydrates (FODMAPs) (55%) were the most reported trigger in adults with dyspepsia. The dyspepsia group (88%) followed special diets more than controls (47%; p < 0.001), with a low FODMAP diet being most common (69%). The dyspepsia group consumed less fiber (p = 0.014), calcium (p = 0.015), and total FODMAPs (p < 0.001) than controls. There was a greater prevalence of comorbid anxiety (41%) and depression (31%) in dyspepsia compared to controls (15% and 12%, respectively, p < 0.001 and p = 0.006). The dyspepsia group had poorer QOL and greater gastrointestinal symptom severity than controls (p < 0.001). There was a negative association between anxiety and CAR (p = 0.001) in dyspepsia but not in controls.

CONCLUSIONS & INFERENCES

Adults with dyspepsia follow special diets more than controls and perceive FODMAPs as a key dietary trigger. These findings highlight the importance of monitoring nutritional adequacy and QOL, and emphasize mechanisms of depleted stress response in dyspepsia, warranting further exploration.

Global trends in research related to functional dyspepsia and anxiety or depression over the past two decades: a bibliometric analysis

Background and purpose

Functional dyspepsia (FD) is a prevalent global disorder of the upper digestive tract characterized by functional impairment. It often coexists with anxiety/depression, significantly impairing occupational productivity and overall quality of life. This study aimed to identify emerging patterns and prominent themes within FD and anxiety/depression research through bibliometric analysis to help explore new innovative avenues for investigating this type of FD.

Methods

A comprehensive review of literature encompassing FD and anxiety/depression was conducted using the Science Citation Index Extension of the Web of Science Core Collection from 2003 to 2023. Information extracted comprised "Full Record and Cited References." Bibliometric analysis of relevant publications, including country, institution, author, journal, citations, and keywords, was conducted using CiteSpace, VOSviewer, and Bibliometrix package in R and Excel.

Results

Studies related to FD and anxiety/depression have demonstrated an ascending trajectory since 2003. Our bibliometric analysis identified 338 studies published by 2023. NEUROGASTROENTEROLOGY AND MOTILITY emerged as the most prolific journal, while GASTROENTEROLOGY retained pre-eminence within the top 10 published journals. China emerged as the most prolific country, with two institutions within the top 10 in terms of volume of publications. The Mayo Clinic stood as the foremost institution in terms of publication volume, with the Chengdu University of Traditional Chinese Medicine exhibiting robust collaborative engagement. Eminent author influence was attributed to Talley NJ of Newcastle University, Australia. Clusters of extensively cited papers and prevalent keywords delineate the status and trend of FD and anxiety/depression research. This encompasses FD, anxiety, depression, sleep disorders, and functional gastrointestinal disorders. Furthermore, the timeline view map or trend-term analysis suggested that duodenal low-grade inflammation ("duodenal eosinophilia" and "mast cells") might be a new concern associated with FD and anxiety/depression.

Conclusion

Employing bibliometric analysis, this study revealed prevalent focal areas and new trends within FD and anxiety/depression research. These insights serve as valuable guidance for scholars seeking to delve into new research avenues.

Clinical-functional brain connectivity signature predicts longitudinal symptom improvement after acupuncture treatment in patients with functional dyspepsia

Whilst acupuncture has been shown to be an effective treatment for functional dyspepsia (FD), its efficacy varies significantly among patients. Knowing beforehand how each patient responds to acupuncture treatment will facilitate the ability to produce personalized prescriptions, therefore, improving acupuncture efficacy. The objective of this study was to construct the prediction model, based on the clinical-neuroimaging signature, to forecast the individual symptom improvement of FD patients following a 4-week acupuncture treatment and to identify the critical predictive features that could potentially serve as biomarkers for predicting the efficacy of acupuncture for FD. Clinical-functional brain connectivity signatures were extracted from samples in the training-test set (100 FD patients) and independent validation set (60 FD patients). Based on these signatures and support vector machine algorithms, prediction models were developed in the training test set, followed by model performance evaluation and predictive features extraction. Subsequently, the external robustness of the extracted predictive features in predicting acupuncture efficacy was evaluated by the independent validation set. The developed prediction models possessed an accuracy of 88% in predicting acupuncture responders, as well as an R2 of 0.453 in forecasting symptom relief. Factors that contributed significantly to stronger responsiveness of patients to acupuncture therapy included higher resting-state functional connectivity associated with the orbitofrontal gyrus, caudate, hippocampus, and anterior insula, as well as higher baseline scores of the Symptom Index of Dyspepsia and shorter durations of the condition. Furthermore, the robustness of these features in predicting the efficacy of acupuncture for FD was verified through various machine learning algorithms and independent samples and remained stable in univariate and multivariate analyses. These findings suggest that it is both feasible and reliable to predict the efficacy of acupuncture for FD based on the pre-treatment clinical-neuroimaging signature. The established prediction framework will promote the identification of suitable candidates for acupuncture treatment, thereby improving the efficacy and reducing the cost of acupuncture for FD.

Nocebo effects in visceral pain: concept and design of the experimental randomized-controlled pain study 'NoVis'

The role of psychological factors in the pathophysiology and treatment of chronic visceral pain in disorders of gut-brain interactions (DGBI) is increasingly appreciated. Placebo research has underscored that expectations arising from the psychosocial treatment context and from prior experiences shape treatment responses. However, effects of negative expectations, i.e., nocebo effects, as they are likely crucial elements of DGBI patients' clinical reality, have thus far only rarely been investigated in the context of visceral pain, with untapped potential for improved prevention and treatment. The experimental randomized-controlled pain study "NoVis," carried out within the Collaborative Research Center (CRC) 289 ("Treatment Expectation"), aims to close gaps regarding the generation and persistence of nocebo effects in healthy volunteers. It is designed to elucidate effects of negative expectations in a multiple-threat paradigm with intensity-matched rectal distensions and cutaneous thermal stimuli, allowing to test nocebo effects in the visceral and somatic pain modalities. Negative expectations are experimentally induced by elements of doctor-patient communication (i.e., instruction) and/or by surreptitious amplification of symptom intensity (i.e., experience/learning) within a treatment context. Accordingly, the repeated measures between-subject design contains the between-group factors "treatment instruction" (negative vs. control) and "treatment experience" (negative vs. control), with volunteers randomized into four experimental groups undergoing several pain stimulation phases (repeated factor). This allows to compare the efficacy of instruction vs. experience, and more importantly, their combined effects on the magnitude of negative expectations and their impact on pain responses, which we expect will be greatest for the visceral modality. After a Baseline, short-term effects are assessed during a test phase accomplished on study day 1 (Test-1 Phase). To explore the persistence of effects, a second test phase is accomplished 1 week later (Test-2 Phase). Effects of negative expectations within and across pain modalities are assessed at the subjective and objective levels, with a focus on psychophysiological and neuroendocrine measures related to stress, fear, and anxiety. Since nocebo effects can play a considerable role in the generation, maintenance, or worsening of chronic visceral pain, and may even constitute risk factors for treatment failure, knowledge from experimental nocebo research has potential to improve treatment outcomes in DGBI and other clinical conditions associated with chronic visceral pain.

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).

Herbal medicine, Banxia-xiexin tang, for functional dyspepsia: a systematic review and meta-analysis

Background: The demand for complementary and alternative medicine for the management of functional dyspepsia (FD) is increasing due to the insufficient efficacy of conventional treatment options. In Asia, the Chinese herbal medicine formula Banxia-xiexin tang (BXT) has been used to treat FD. Methods: We searched 11 digital medical databases on 1 September 2021. Randomized controlled trials (RCTs) that investigated the efficacy of BXT or combination therapy (BXT plus Western medicines) for FD were selected. The outcome parameters were total clinical efficacy rate (TCE), motilin level, symptom checklist-90-revised (SCL-90-R), and visual analog scale (VAS) for dyspepsia and adverse events. Cochrane risk of bias tool 2.0 (RoB 2) was used for the quality assessment of included studies. Results: The meta-analysis comprised 57 RCTs with 5,525 participants. BXT was more efficacious, with a higher TCE than Western medicine. Combination therapy (BXT plus Western medicine) also resulted in a higher TCE than Western medicine. Combination therapy improved motilin levels and psychological symptoms to a greater extent than Western medicine, evidenced by a higher SCL-90-R score. However, no significant difference in VAS scores was observed between the BXT and placebo groups. BXT and combination therapy were associated with fewer adverse events than Western medicine or placebo. Conclusion: Our findings suggest that BXT and its combination therapy may be an effective and safe alternative treatment for FD. More RCTs with better methodologies are required to strengthen this evidence. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019123285], identifier [CRD42019123285].

Gut Microbiome-Brain Alliance: A Landscape View into Mental and Gastrointestinal Health and Disorders

Gut microbiota includes a vast collection of microorganisms residing within the gastrointestinal tract. It is broadly recognized that the gut and brain are in constant bidirectional communication, of which gut microbiota and its metabolic production are a major component, and form the so-called gut microbiome-brain axis. Disturbances of microbiota homeostasis caused by imbalance in their functional composition and metabolic activities, known as dysbiosis, cause dysregulation of these pathways and trigger changes in the blood-brain barrier permeability, thereby causing pathological malfunctions, including neurological and functional gastrointestinal disorders. In turn, the brain can affect the structure and function of gut microbiota through the autonomic nervous system by regulating gut motility, intestinal transit and secretion, and gut permeability. Here, we examine data from the CAS Content Collection, the largest collection of published scientific information, and analyze the publication landscape of recent research. We review the advances in knowledge related to the human gut microbiome, its complexity and functionality, its communication with the central nervous system, and the effect of the gut microbiome-brain axis on mental and gut health. We discuss correlations between gut microbiota composition and various diseases, specifically gastrointestinal and mental disorders. We also explore gut microbiota metabolites with regard to their impact on the brain and gut function and associated diseases. Finally, we assess clinical applications of gut-microbiota-related substances and metabolites with their development pipelines. We hope this review can serve as a useful resource in understanding the current knowledge on this emerging field in an effort to further solving of the remaining challenges and fulfilling its potential.

Gastroparesis: The Complex Interplay with Microbiota and the Role of Exogenous Infections in the Pathogenesis of the Disease

Gastroparesis (GP) is a disorder of gastric functions that is defined by objective delayed gastric emptying in the absence of mechanical obstruction. This disease is characterized by symptoms such as nausea, post-prandial fullness, and early satiety. GP significantly impacts patients' quality of life and contributes to substantial healthcare expenses for families and society. However, the epidemiological burden of GP is difficult to evaluate, mainly due its significant overlap with functional dyspepsia (FD). GP and FD represent two similar diseases. The pathophysiology of both disorders involves abnormal gastric motility, visceral hypersensitivity, and mucosal inflammation. Moreover, both conditions share similar symptoms, such as epigastric pain, bloating, and early satiety. The latest evidence reveals that dysbiosis is directly or indirectly connected to gut-brain axis alterations, which are the basis of pathogenesis in both FD and GP. Furthermore, the role of microbiota in the development of gastroparesis was demonstrated by some clinical studies, which found that the use of probiotics is correlated with improvements in the gastric emptying time (GET). Infections (with viruses, bacteria, and protozoa) represent a proven etiology for GP but have not been sufficiently considered in current clinical practice. Previous viral infections can be found in about 20% of idiopathic GP cases. Moreover, delayed gastric emptying during systemic protozoal infections represents a huge concern for compromised patients, and few data exist on the topic. This comprehensive narrative review analyzes the relationship between microorganisms and GP. We explore, on the one hand, the correlation between gut microbiota dysbiosis and GP pathogenesis, including treatment implications, and, on the other hand, the association between exogenous infections and the etiology of the disease.

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Clinical Efficacy of Tandospirone on Functional Dyspepsia Patients with Anxiety: A Randomized, Placebo-Controlled Study

BACKGROUND

Functional dyspepsia (FD) is characterized with multiple symptoms of indigestion and often accompanied with anxiety. However, there is currently an absence of effective treatment. Tandospirone is commonly used to treat generalized anxiety disorders. Whether tandospirone can improve the clinical symptoms of FD remain unknown.

AIMS

The present study was designed to explore the pharmacological effect of tandospirone on FD patient with anxiety, and the potential mechanisms were also elucidated.

METHODS

FD patients with anxiety were randomly divided into placebo and tandospirone treatment groups. Healthy volunteers were simultaneously recruited as control group. The gastrointestinal symptom score (GIS) and Hamilton anxiety scale (HAM-A) were performed before and after treatments with placebo or tandospirone. The serum levels of brain-derived neurotrophic factor (BDNF) and multiple inflammatory cytokines including tumor necrosis factor-α (TNF-α), and interleukin (IL)-6, IL-4, IL-1β, and IL-10 were determined. Regression analyses relating BDNF levels and gastrointestinal symptoms were performed.

RESULTS

Tandospirone significantly alleviated the gastrointestinal and anxiety symptoms of FD patient, as evidenced by reductions of GIS index and HAM-A scores. Compared with the healthy volunteers, FD patients had lower BDNF and IL-10 levels, but higher levels of IL-6 and TNF-α. Importantly, tandospirone increased serum BDNF and IL-10 and decreased IL-6 levels in FD patients. Relative analysis revealed that BDNF level was negatively associated with gastrointestinal symptoms in FD patients.

CONCLUSION

Tandospirone effectively improved both anxiety and gastrointestinal symptoms of patients with FD, and these therapeutic effects may be associated with the modulation of BDNF and inflammatory cytokines.

METTL3 contributes to slow transit constipation by regulating miR-30b-5p/PIK3R2/Akt/mTOR signaling cascade through DGCR8

BACKGROUND

N6-methyladenosine (m6A) is the most prevalent methylation modification of eukaryotic RNA, and methyltransferase-like 3 (METTL3) plays a vital role in multiple cell functions. This study aimed to investigate the role of m6A methylase METTL3 in slow transit constipation (STC).

MATERIAL AND METHOD

The expression of METTL3 and DGCR8 was measured in STC tissues and glutamic acid-induced interstitial cells of Cajal (ICCs). The effects of METTL3, miR-30b-5p, and DGCR8 on the biological characteristics of ICCs were investigated on the basis of loss-of-function analyses. Luciferase reporter assay was used to identify the direct binding sites of miR-30b-5p with PIK3R2.

RESULTS

The results showed that the METTL3, DGCR8, miR-30b-5p, and the methylation level of m6A were significantly increased in STC tissues and glutamic acid-induced ICCs. Silencing of METTL3 and miR-30b-5p inhibited apoptosis, autophagy, and pyroptosis of glutamic acid-induced ICCs. Moreover, overexpression of miR-30b-5p reversed the cytoprotection of METTL3 knockdown in glutamic acid-induced ICCs. Besides, DGCR8 knockdown could facilitate cell growth and decrease apoptotic glutamic acid-induced ICCs. Mechanically, we illustrated that METTL3 in glutamic acid-induced ICCs significantly accelerated the maturation of pri-miR-30b-5p by m6A methylation modification, resulting in the reduction of PIK3R2, which results in the inhibition of PI3K/Akt/mTOR pathway and ultimately leads to the cell death of STC.

CONCLUSIONS

Collectively, these data demonstrated that METTL3 promoted the apoptosis, autophagy, and pyroptosis of glutamic acid-induced ICCs by interacting with the DGCR8 and successively modulating the miR-30b-5p/PIK3R2 axis in an m6A-dependent manner, and METTL3 may be a potential therapeutic target for STC.

Reduced mastication is a risk factor for Rome IV postprandial distress syndrome in patients investigated with upper endoscopy

BACKGROUND AND AIMS

Reduced mastication could force the stomach to do extra work on crushing food and contribute to dyspeptic symptoms. This study aimed to assess the relationship between mastication and dyspepsia.

METHODS

This cross-sectional study involved 209 consecutive patients referred for elective upper endoscopy. Before endoscopy, an expert dentist performed an oral examination and scored chewing function in three levels (normal, regular, and reduced), and applied questionnaires for assessment of dyspepsia (Rome IV), xerostomia, and mastication (normal, regular, and reduced). A reduced masticatory function was defined when an oral examination or mastication questionnaire rated the chewing as poor. Associations between mastication, confounders, and dyspepsia were estimated by prevalence ratio [PR (95% Confidence Interval)] using Poisson regression.

RESULTS

Thirty-four patients showed relevant organic conditions in the upper gastrointestinal tract (moderate to severe reflux oesophagitis, peptic ulcer, neoplasia, and surgical modification) and were excluded. Among 175 patients with non-organic diseases (aging 51.3 ± 15.7 years; 61.7% women), 50 (28.6%) had reduced mastication, and 125 (71.4%) had normal/regular mastication. After adjusting for age and xerostomia, reduced mastication was associated with postprandial distress syndrome [PR = 1.93 (95%CI 1.27 - 2.91)] but not with epigastric pain syndrome [PR = 1.09 (95%CI 0.75 - 1.60)].

CONCLUSIONS

In patients referred for upper digestive endoscopy, reduced mastication was associated with postprandial distress syndrome but not with epigastric pain syndrome. An interdisciplinary approach with dentists and physicians might benefit dyspeptic patients with postprandial distress syndrome.

Role of the duodenal microbiota in functional dyspepsia

BACKGROUND

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

PURPOSE

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

Quantification of prevalence, clinical characteristics, co-existence, and geographic variations of traditional Chinese medicine diagnostic patterns via latent tree analysis-based differentiation rules among functional dyspepsia patients

Background

Traditional Chinese Medicine (TCM) treatment strategies are guided by pattern differentiation, as documented in the eleventh edition of the International Classification of Diseases (ICD). However, no standards for pattern differentiation are proposed to ensure inter-rater agreement. Without standardisation, research on associations between TCM diagnostic patterns, clinical features, and geographical characteristics is also not feasible. This diagnostic cross-sectional study aimed to (i) establish the pattern differentiation rules of functional dyspepsia (FD) using latent tree analysis (LTA); (ii) compare the prevalence of diagnostic patterns in Hong Kong and Hunan; (iii) discover the co-existence of diagnostic patterns; and (iv) reveal the associations between diagnostic patterns and FD common comorbidities.

Methods

A total of 250 and 150 participants with FD consecutively sampled in Hong Kong and Hunan, respectively, completed a questionnaire on TCM clinical features. LTA was performed to reveal TCM diagnostic patterns of FD and derive relevant pattern differentiation rules. Multivariate regression analyses were performed to quantify correlations between different diagnostic patterns and between diagnostic patterns and clinical and geographical variables.

Results

At least one TCM diagnostic pattern was differentiated in 70.7%, 73.6%, and 64.0% of the participants in the overall (n = 400), Hong Kong (n = 250), and Hunan (n = 150) samples, respectively, using the eight pattern differentiation rules derived. 52.7% to 59.6% of the participants were diagnosed with two or more diagnostic patterns. Cold-heat complex (59.8%) and spleen-stomach dampness-heat (77.1%) were the most prevalent diagnostic patterns in Hong Kong and Hunan, respectively. Spleen-stomach deficiency cold was highly likely to co-exist with spleen-stomach qi deficiency (adjusted odds ratio (AOR): 53.23; 95% confidence interval (CI): 21.77 to 130.16). Participants with severe anxiety tended to have liver qi invading the stomach (AOR: 1.20; 95% CI: 1.08 to 1.33).

Conclusions

Future updates of the ICD, textbooks, and guidelines should emphasise the importance of clinical and geographical variations in TCM diagnosis. Location-specific pattern differentiation rules should be derived from local data using LTA. In future, patients’ pattern differentiation results, local prevalence of TCM diagnostic patterns, and corresponding TCM treatment choices should be accessible to practitioners on online clinical decision support systems to streamline service delivery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00656-x.

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.

The Effects of Psychological Interventions on Symptoms and Psychology of Functional Dyspepsia: A Systematic Review and Meta-Analysis

Background

The effects of psychological interventions on symptoms and psychology of functional dyspepsia (FD) remain unclear. We aimed to comprehensively evaluate the effects of psychological interventions on symptoms and psychology of FD.

Methods

We searched the PubMed, Cochrane Library, and Embase electronic databases for randomized controlled trials (RCTs) evaluating the role of psychological interventions in FD patients published before July 2021. Standardized mean differences (SMDs), risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by a random effects model. Subgroup analyses and sensitivity analyses were also performed.

Results

Fourteen RCTs with a total of 1,434 FD patients were included. Compared with the control group, psychological interventions were significantly more likely to symptom improvement [RR = 1.74, 95% CI (1.12, 2.72), p = 0.01], relieve gastrointestinal symptoms scores at follow up [SMD = −1.06, 95% CI (−1.55, −0.57), p < 0.0001], relieve gastrointestinal symptoms scores at end of treatment [SMD = −0.98, 95% CI (−1.29, −0.67), p < 0.001], decrease anxiety [SMD = −0.8, 95% CI (−1.38, −0.22), p = 0.006] and depression levels [SMD = −1.11, 95% CI (−1.62, −0.61), p < 0.001]. The results of the subgroup analysis showed that psychotherapy was more likely to symptom improvement, relieve gastrointestinal symptoms scores and decreased depression levels compared to the control.

Conclusions

Psychological interventions may be effective in alleviating the symptoms and psychology of FD, but the effect appears to be limited to psychotherapy with fewer trials for other psychological interventions. More data from high-quality RCTs are needed to confirm their use in the treatment of FD.

Chemical Design of Activatable Photoacoustic Probes for Precise Biomedical Applications

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

Defects in NLRP6, autophagy and goblet cell homeostasis are associated with reduced duodenal CRH receptor 2 expression in patients with functional dyspepsia

Functional dyspepsia (FD) affects up to 15% of the population and is characterised by recurring upper gastrointestinal (GI) symptoms occurring in the absence of clinically identifiable pathology. Psychological stress is a key factor associated with the onset of FD and locally acting hypothalamic-pituitary-adrenal (HPA) axis hormones have been implicated in GI motility and barrier dysfunction. Recent pre-clinical work has identified mechanistic pathways linking corticotropin-releasing hormone (CRH) with the innate epithelial immune protein NLRP6, an inflammasome that has been shown to regulate GI mucus secretion. We recruited twelve FD patients and twelve healthy individuals to examine whether dysregulation of hypothalamic-pituitary adrenal (HPA) axis hormones and altered NLRP6 pathways were evident in the duodenal mucosa. Protein expression was assessed by immunoblot and immunohistochemistry in D2 duodenal biopsies. Plasma HPA axis hormones were assayed by ELISA and enteroid and colorectal cancer cell line cultures were used to verify function. FD patients exhibited reduced duodenal CRH-receptor 2, compared to non-GI disease controls, indicating a dysregulation of duodenal HPA signalling. The loss of CRH-receptor 2 correlated with reduced NLRP6 expression and autophagy function, processes critical for maintaining goblet cell homeostasis. In accordance, duodenal goblet cell numbers and mucin exocytosis was reduced in FD patients compared to controls. In vitro studies demonstrated that CRH could reduce NLRP6 in duodenal spheroids and promote mucus secretion in the HT29-MTX-E12 cell line. In conclusion, FD patients exhibit defects in the NLRP6-autophagy axis with decreased goblet cell function that may drive symptoms of disease. These features correlated with loss of CRH receptor 2 and may be driven by dysregulation of HPA signalling in the duodenum of FD patients.

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

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

Subcortical-Cortical Functional Connectivity as a Potential Biomarker for Identifying Patients with Functional Dyspepsia

The diagnosis of functional dyspepsia (FD) presently relies on the self-reported symptoms. This study aimed to determine the potential of functional brain network features as biomarkers for the identification of FD patients. Firstly, the functional brain Magnetic Resonance Imaging data were collected from 100 FD patients and 100 healthy subjects, and the functional brain network features were extracted by the independent component analysis. Then, a support vector machine classifier was established based on these functional brain network features to discriminate FD patients from healthy subjects. Features that contributed substantially to the classification were finally identified as the classifying features. The results demonstrated that the classifier performed pretty well in discriminating FD patients. Namely, the accuracy of classification was 0.84 ± 0.03 in cross-validation set and 0.80 ± 0.07 in independent test set, respectively. A total of 15 connections between the subcortical nucleus (the thalamus and caudate) and sensorimotor cortex, parahippocampus, orbitofrontal cortex were finally determined as the classifying features. Furthermore, the results of cross-brain atlas validation showed that these classifying features were quite robust in the identification of FD patients. In summary, the current findings suggested the potential of using machine learning method and functional brain network biomarkers to identify FD patients.

The Neuroprotective Effect of Increased PINK1 Expression Following Glutamate Excitotoxicity in Neuronal Cells

Ischemic injury in patients with stroke often leads to neuronal damage and mitochondrial dysfunction. Neuronal injury caused by ischemia can be partly attributed to glutamate (L-Glu) excitotoxicity. Previous studies have shown that PTEN-induced kinase 1 (PINK1) plays a neuroprotective role in ischemic brain injury by regulating mitochondrial integrity and function. However, there are few reports on the expression of PINK1 in L-Glu excitotoxicity models, its effect on neuronal survival, and whether PINK1 plays a protective role in stroke by regulating mitophagy. In the present study, different concentrations of L-Glu inhibited the viability of neurons. After L-Glu treatment at different times, the mRNA level, protein level, and cellular fluorescence intensity of PINK1 first increased and then decreased. Compared with normal cells, cells with low PINK1 expression enhanced the inhibitory effect of L-Glu on neuronal activity, while those with high PINK1 expression showed a protective effect on neurons by alleviating mitochondrial membrane potential loss. In addition, RAP (an autophagy activator) could increase the co-localization of the mitophagy-related proteins light chain 3 (LC3) and Tom20, whereas 3-MA (an autophagy inhibitor) exerted the opposite effect. Finally, we found that L-Glu could induce the expression of PINK1/Parkin/ LC3 in neurons at both mRNA and protein levels, while RAP could further increase their expression, and 3-MA decreased their expression. Taken together, PINK1 protects against L-Glu-induced neuronal injury by protecting mitochondrial function, and the potential protective mechanism may be closely related to the enhancement of mitophagy mediated by the PINK1/Parkin signaling pathway.

Effect of a Persian metabolic diet on the functional dyspepsia symptoms in patients with postprandial distress syndrome: a randomized, double-blind clinical trial

OBJECTIVES

Postprandial distress syndrome (PDS) is associated with food indigestion. Efficacy of drugs used against PDS is limited whereas dietary modifications were shown to have important beneficial effects. Traditional Persian Medicine (TPM) sages suggested a dietary regimen known as Persian metabolic diet (PMD) for the management of PDS patients. In this study, the efficacy of PMD in alleviating the symptoms of PDS was explored.

METHODS

This single-center, parallel-group, randomized clinical trial included 56 patients whom were randomly allocated to PMD group (29 participants) and Optional diet (OD) group (27 participants). They were instructed to follow the protocol for two weeks. Using a standard validated questionnaire, all outcomes were evaluated at baseline, end of the intervention period, and end of follow-up time.

RESULTS

At the end of the intervention period, comparing the changes of severity scores between the groups showed a statistically significant difference in week 2 (p-value<0.001) and week 8 (p-value<0.001) follow-up comparing to the baseline. Similarly, at the end of the follow-up period, epigastric fullness, epigastric discomfort, and bloating were significantly improved in the PMD group (p<0.001).

CONCLUSIONS

This diet prepared based on Persian medicine seems to be effective in relieving the symptoms of patients with PDS.

Duodenum at a crossroads: Key integrator of overlapping and psychological symptoms in functional dyspepsia?

The study of the interaction between gastrointestinal (GI) function and psychological features is a complex and developing field. The bidirectional communication between the gut and the brain or gut-brain axis is considered as a pivotal player in the pathogenesis of the highly prevalent functional GI disorders, including irritable bowel syndrome and functional dyspepsia (FD), which have been redefined as disorders of gut-brain interaction. However, the mechanisms through which changes in the gut alter brain functioning, feelings, and behavior remain unclear. Based on the presence of duodenal pathology in adult FD patients, Ronkainen et al. provide the first prospective evidence for duodenal eosinophils potentially driving anxiety. Also in this edition, associations between gastroduodenal pathology and rumination syndrome, which may coexist with FD, have now been confirmed in children by Friesen et al. Together these findings confirm not only the potential role of duodenal alterations in determining overlapping upper GI but also psychological symptoms, which result from bidirectional and complex interactions. In this review, we provide an overview of the recent advances in this field and highlight the novel contributions of the original studies of Ronkainen et al. and Friesen et al. to this topic.

Relative risk of functional dyspepsia in patients with sleep disturbance: a population-based cohort study

Increased prevalence of sleep disorders has been found in patients with functional dyspepsia; however, direction of causality remains unclear. Our aim was to compare the risk of incident functional dyspepsia between patients with and without sleep disturbance from a large population-based sample. Utilizing a nation-wide health insurance administrative dataset, we assembled an 11-year historic cohort study to compare subsequent incidence of diagnosed functional dyspepsia between adult patients with any diagnosis of sleep disturbance and age- and gender-matched controls. Hazard ratios adjusted for other relevant comorbidities and medications were calculated using Cox regression models. 45,310 patients with sleep disorder and 90,620 controls were compared. Patients with sleep apnea had a 3.3-fold (95% confidence interval: 2.82 ~ 3.89) increased hazard of functional dyspepsia compared with controls. This increased risk persisted regardless of previously diagnosed depression coexisted. Sleep disturbance was associated with an increased risk of subsequent functional dyspepsia. Potential mechanisms are discussed.

Are psychological interventions effective in treating functional dyspepsia? A systematic review and meta-analysis

BACKGROUND AND AIM

Functional dyspepsia (FD) is a common gastrointestinal disorder, characterized primarily by postprandial fullness or early satiety and/or pain in the epigastrium with no endoscopic evidence of disease. Psychological therapies have been adapted to the treatment of disordered gut-brain interaction such as FD. We sought to determine if psychological interventions were efficacious in providing symptom management and improving health-related quality of life in patients suffering from FD.

METHODS

Data were sorted that belonged to Embase (1947 to January 2020), PsychINFO (1806 to January 2020), and Ovid MEDLINE (1946 to January 2020). Randomized controlled trials using a psychological intervention in adults meeting relevant diagnostic criteria for FD were included. Data including symptom scores and quality of life measures were extracted. A random-effect model meta-analysis with standardized mean differences was used.

RESULTS

Nine randomized controlled trials were identified that met our inclusion criteria. These were small, single-centered studies and used varying psychological therapies. Three studies had a sham treatment arm, leading to a high risk of bias in the remaining studies. All the studies reported beneficial effects of psychological treatment on patient's symptoms, some of which persisted up to 1 year. Psychological intervention was associated with an improvement in global FD symptom scores (standardized differences in means -1.33, 95% confidence interval -1.97 to -0.68).

CONCLUSIONS

Despite the limited data, the available evidence suggests that psychological therapy is beneficial in treating patients with FD and should be considered by treating physicians if available and patients are willing. Large well-designed, sham controlled trials are needed for this extremely common disorder.

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.

Functional Dyspepsia: Diagnostic and Therapeutic Approaches

Functional dyspepsia is a common functional gastrointestinal (GI) disorder of gastroduodenal origin, diagnosed clinically in the presence of prototypical symptoms of epigastric pain and meal-related symptoms, and without structural explanation. The most recent diagnostic criteria provide for two functional dyspepsia subtypes, epigastric pain syndrome (EPS) and post-prandial distress syndrome (PDS) based on the predominant symptom pattern. The evaluation of dyspepsia should keep laboratory, imaging, and invasive testing to a minimum, as extensive or repetitive investigations are of rather low diagnostic yield in the absence of localizing symptoms or alarm features. Factors with etiopathologic relationships to functional dyspepsia include micro-inflammation, GI infections, abnormalities of gastroduodenal motility, visceral hypersensitivity, disturbances along the brain-gut axis, and psychological factors; all of these causative mechanisms have potential to partially explain symptoms in some functional dyspepsia patients, thus providing a rationale for the efficacy of a diversity of therapeutic approaches to functional dyspepsia. Management of dyspepsia symptoms relies upon both pharmacologic treatments and non-pharmacologic approaches, including psychological and complementary interventions. The evidence in support of established functional dyspepsia therapies is reviewed, and forms the basis for an effective functional dyspepsia treatment strategy emphasizing the patient's current symptom severity, pattern, and impact on the function and quality of life of the individual.

Irritable bowel syndrome and functional dyspepsia in patients with eating disorders - a systematic review

OBJECTIVES

The prevalence of eating disorders is rising worldwide. The low body weight in anorexia nervosa as well as the increase in body mass index due to binge eating disorder are contributing to a strikingly high morbidity and mortality. In a similar pattern, the prevalence and burden of the disease of functional gastrointestinal disorders such as functional dyspepsia and irritable bowel syndrome is increasing. As gastrointestinal complaints are commonly reported by patients with eating disorders, the question arose whether there is a relationship between eating disorders and functional gastrointestinal disorders.

METHODS

To address the need to better understand the interplay between eating disorders and functional gastrointestinal disorders as well as factors that might influence this connection, the data bases Medline, Web of Science and Embase were systematically searched.

RESULTS

After removal of duplicates the search yielded 388 studies which were screened manually. As a result, 36 publications were selected for inclusion in this systematic review.

CONCLUSION

The occurrence of functional gastrointestinal disorders like irritable bowel syndrome and functional dyspepsia in patients with eating disorders is considerably high and often associated with psychological, hormonal and functional alterations. In the future, further research addressing the underlying mechanisms accounting for this relationship is required.

Comparative efficacy and acceptability of psychotropic drugs for functional dyspepsia in adults: A systematic review and network meta-analysis

ABSTRACT

Psychotropic drugs are frequently used for functional dyspepsia (FD); however, the efficacy of these drugs for treating FD remains controversial. We aimed to comprehensively compare the relative efficacies of different psychotropic drugs for FD in adults.To conduct this study, we searched the PubMed, Embase, and Cochrane Library databases on March 10, 2019, and conducted a frequentist network meta-analysis on the search results. The primary outcome was treatment efficacy estimated by the proportion of patients who achieved a certain percentage decrease in symptoms or who dropped below the threshold of the global FD symptom scores. The secondary outcome was acceptability, defined as all-cause discontinuation. Odds ratios (ORs) were reported with 95% confidence intervals (CIs).We deemed 10 trials to be eligible for analysis, and these trials included 970 participants and 10 psychotropic drugs. Flupentixol + melitracen (F + M) (OR, 10.00; 95% CI, 1.59 to 62.73), tandospirone (3.24, 1.38 to 7.60), imipramine (2.21, 1.02 to 4.79), and amitriptyline (1.71, 1.06 to 3.09) were significantly superior to placebo. According to the surface under the cumulative ranking curve, the most effective treatment was F + M (89.0%), whereas the least effective was R137696 (13.6%). In terms of acceptability, escitalopram (0.32, 0.11 to 0.92) was ranked as the worst drug (12.6%), followed by imipramine and sertraline.The present network meta-analysis suggests that F + M, tandospirone, imipramine, and amitriptyline are more effective than placebo as treatment for FD. Our results indicate that among the ten psychotropic drugs included, F + M is likely to be the most effective drug for alleviating dyspepsia symptoms.

Impact of COVID-19 lockdown on symptoms in patients with functional gastrointestinal disorders: Relationship with anxiety and perceived stress

BACKGROUND

Psychological stress and anxiety, such those generated by forced quarantine, affect gastrointestinal symptoms course in patients with functional gastrointestinal disorders. Thus, our aim was to assess, in a cohort of patients regularly followed up in a devoted outpatient clinic of Southern Italy, the association between their gastrointestinal symptoms changes, stress, and anxiety reported during the Italian lockdown.

METHODS

We recruited patients from the outpatient clinic of the University of Salerno, devoted to functional gastrointestinal disorders, selecting only patients for whom an evaluation was available in the last 6 months before the lockdown. Gastrointestinal symptoms were evaluated at each visit through standardized questionnaire and pooled in a database. On 45th days from the beginning of the lockdown, patients were re-assessed by phone with the same questionnaire. Anxiety and stress levels were assessed through a self-administered online questionnaire based on Generalized Anxiety Disorder 7 test and Perceived Stress Scale 10 test.

KEY RESULTS

The intensity-frequency scores of several upper gastrointestinal symptoms improved (Wilcoxon test <0.05). Higher anxiety levels had a higher risk of worsening chest pain (OR 1.3 [1.1-1.7]), waterbrash (OR 1.3 [1.0-1.7]), epigastric burning (OR 1.3 [1.0-1.6]), and abdominal pain (OR 1.6 [1.0-2.3]). When compared to the interval preceding the outbreak, half of the patients declared their symptoms remained unchanged, 13.6% worsened, and 36.4% improved.

CONCLUSIONS AND INFERENCES

During the COVID-19 quarantine, there was an improvement of the majority of upper gastrointestinal symptoms in our patients, and anxiety seems an important risk of worsening few of them.

Mechanisms of Food-Induced Symptom Induction and Dietary Management in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, characterised by upper gastrointestinal symptom profiles that differentiate FD from the irritable bowel syndrome (IBS), although the two conditions often co-exist. Despite food and eating being implicated in FD symptom induction, evidence-based guidance for dietetic management of FD is limited. The aim of this narrative review is to collate the possible mechanisms for eating-induced and food-related symptoms of FD for stratification of dietetic management. Specific carbohydrates, proteins and fats, or foods high in these macronutrients have all been reported as influencing FD symptom induction, with removal of 'trigger' foods or nutrients shown to alleviate symptoms. Food additives and natural food chemicals have also been implicated, but there is a lack of convincing evidence. Emerging evidence suggests the gastrointestinal microbiota is the primary interface between food and symptom induction in FD, and is therefore a research direction that warrants substantial attention. Objective markers of FD, along with more sensitive and specific dietary assessment tools will contribute to progressing towards evidence-based dietetic management of FD.

Gut-Brain Axis Exploration: Stabilometric Platform Performances in Children Affected by Functional Gastrointestinal Disorders

OBJECTIVE

The pathophysiology of functional gastrointestinal disorders (FGIDs) is associated with dysfunction at various levels of the gut-brain axis. Hypervigilance can result in an increased tendency to report pain. In the present study, we aimed to explore whether hypervigilance can influence attentional processing in postural control in children with FGIDs.

PATIENTS AND METHODS

Fifty-nine participants classified into healthy subjects, those with FGIDs, and those with organic diseases (Org) based on Rome IV criteria were enrolled. Postural control under 6 sensory conditions was evaluated using a stabilometric platform. The mean velocity of the center of pressure (CoP) displacement in the anteroposterior direction and the mediolateral direction, the length of the CoP trajectory, and the sway area were also measured.

RESULTS

With visual and somatosensorial normal inputs, participants with FGIDs showed a higher number of anteroposterior (FGIDs: 4[interquartile range [IQR] 3-7], control [Cntl] 3 [IQR 3-4], P  < 0.05) latero-lateral oscillations (FGIDs: 3 [IQR 3-6], Cntl 3 [IQR 2-3], P  < 0.05) and a higher perimeter value (FGIDs: 148 [IQR 121-240], Cntl 124 [IQR 111-140], P  = 0.056) compared to healthy subjects. With normal visual but altered somatosensorial input, subjects with FGIDs showed higher values of all parameters (anteroposterior: FGIDs 6[IQR 5-8], Cntl and Org 5 [IQR 4-6], P  < 0.05; latero-lateral FGIDs 6 [IQR 4-8], Cntl 4 [IQR 4-5], Org 4[IQR 3-5], P  < 0.05; perimeter FGIDs 253 [IQR 167-305], Cntl 185 [IQR 161-217], Org 176 [IQR 142-219], P  < 0.05; area FGIDs 98 [IQR 81-233], Cntl 86 [IQR 59-114], Org 56 [IQR 41-97], P < 0.05).

CONCLUSIONS

The higher number of oscillations in subjects with FGIDs who had normal visual input could be expression of alteration in attention and therefore hypervigilance as hypothesized in the context of gut-brain axis alterations.

Persian Herbal Medicine in Functional Dyspepsia: A Systematic Review

INTRODUCTION

According to Rome IV, functional dyspepsia is diagnosed with the presence of dyspepsia in the absence of organic or metabolic causes. FD caused by several factors, such as impaired gastric accommodation and hypersensitivity to gastric distention. Several studies have reported the effectiveness of herbal medicine on FD. This article, thus, reviews Persian herbal medicine in FD.

METHODS

Electronic databases, including Pubmed, Scopus, Cochrane, Embase, Web of science and Ovid, were searched so as to find clinical articles related to dyspepsia and herbal medicine by July 2019. Our search strategies were traditional medicine, complementary and alternative medicine, herb, plant, and dyspepsia. We excluded all articles except Persian clinical trials.

RESULTS

We found 34 clinical trials with 15 herbs and 4 compound herbal remedies like Asparagus racemosus, Brassica oleracea, Cynara scolymus, Ocimum basilicum, Mentha longifolia, Mentha pulegium, Mentha piperata, Pimpinella anisum, Nigella sativa, Mastic gum, Curcuma longa, Pistatio Atlantica, Glycyrrhiza glabra, Solanum tuberosum and Zingiber officinale and compound remedies of Rosa damascene & Crocus sativus, Trachyspermum copticom & Apium graveolence, Carum carvi & Mentha pipperata, Gingiber officinalis & Cynara scolymus are effective in functional dyspepsia.

CONCLUSION

Many people use herbal and traditional remedies for the treatment of disorders such as gastrointestinal disorders, especially in Asian countries. Several studies reported the efficacy of herbal medicine in functional dyspepsia. Although their mechanisms are not fully understood, it seems they can modulate GI motility and improve symptoms of FD.

Avoidant/restrictive food intake disorder symptoms are frequent in patients presenting for symptoms of gastroparesis

INTRODUCTION

Patients with symptoms of gastroparesis/dyspepsia often avoid foods or restrict eating for symptom management. There is growing interest in understanding risk for feeding/eating disorders (FEDs) like avoidant/restrictive food intake disorder (ARFID). Among patients presenting with gastroparesis/dyspepsia symptoms, we aimed to determine: (a) FED symptom frequency, and (b) relation of FED symptoms to gastrointestinal symptom severity and gastric retention abnormalities.

METHODS

Adult patients (N = 288; 78% female) referred for gastroparesis/dyspepsia symptoms at two academic medical centers from January 2018-February 2019 completed self-report surveys for gastrointestinal symptom severity and FED symptoms. Gastric retention data were available for 210 patients, using 4-hour EggBeater gastric emptying scintigraphy (GES).

RESULTS

Clinically significant FED symptoms were present in 158 patients (54.9%). Interestingly, 115 patients (39.9%) met conservative self-report cutoff for ARFID symptoms, with 67 (23.3%) patients having documented psychosocial/medical impairment. Of those with survey data for other FEDs (n = 239), only 28 patients (11.7%) had restrictive eating disorders (anorexia nervosa; unspecified FED). Likelihood of having FED symptoms was significantly associated with greater gastroparesis symptom severity (OR = 2.23, P < .001), but not GES. In addition, gastroparesis symptom severity was moderately and significantly associated with greater ARFID symptom severity (b = 0.45, P < .001), but neither GES nor other FED symptoms.

DISCUSSION

In patients presenting with gastroparesis/dyspepsia symptoms, FED symptoms were frequent (55%), particularly ARFID, and were associated with greater gastrointestinal symptom severity, but not gastric retention. Gastroparesis/dyspepsia symptoms may mimic FEDs, particularly ARFID. Clinicians should be cautious about diagnosing ARFID in gastroparesis/dyspepsia patients, and screening for ARFID could assist behavioral treatment referral.

Intrinsic functional brain connectivity patterns underlying enhanced interoceptive sensibility

BACKGROUND

Cumulative evidence has suggested that brain regions including the bilateral insula and the anterior cingulate cortex play critical roles in the processing of interoceptive information. However, the brain functional connectivity patterns underlying interoceptive sensibility (IS) and their role in the relationship between IS and self-reported bodily symptoms remain unknown. We aimed to investigate the intrinsic functional connectivity patterns associated with IS and how this modulates the relationship between IS and self-reported bodily symptoms.

METHODS

Resting-state functional magnetic resonance imaging was used to test the intrinsic large-scale functional connectivity in 459 healthy subjects. IS and self-reported bodily symptoms were assessed by questionnaires.

RESULTS

Individuals with greater IS had a stronger tendency to report bodily symptoms. Higher IS was correlated with decreased ventral anterior insula-superior temporal gyrus, dorsal anterior cingulate cortex-middle frontal cortex and amygdala-medioventral occipital cortex connectivity. The large-scale functional connectivity of cingulo-opercular task control network (CON)-default mode network, CON-subcortical network and CON-dorsal attention network moderated the association between IS and bodily symptoms.

LIMITATIONS

The Body Perception Questionnaire mainly reflects the self-perceived tendency to focus on negatively-valenced interoceptive sensations. Future research should distinguish neutral and negative IS in order to make the definition of IS clearer.

CONCLUSIONS

This study suggests that IS may be related to impaired intrinsic functional connectivity between brain areas related to multisensory integration and cognitive-affective control, resulting in increased vigilance-attention to bodily signals. These findings offer new empirical evidence for a better understanding of the intricate relationships between interoception and symptom reporting.

Role of gut microbiota via the gut-liver-brain axis in digestive diseases

The gut-brain axis is a bidirectional information interaction system between the central nervous system (CNS) and the gastrointestinal tract, in which gut microbiota plays a key role. The gut microbiota forms a complex network with the enteric nervous system, the autonomic nervous system, and the neuroendocrine and neuroimmunity of the CNS, which is called the microbiota-gut-brain axis. Due to the close anatomical and functional interaction of the gut-liver axis, the microbiota-gut-liver-brain axis has attracted increased attention in recent years. The microbiota-gut-liver-brain axis mediates the occurrence and development of many diseases, and it offers a direction for the research of disease treatment. In this review, we mainly discuss the role of the gut microbiota in the irritable bowel syndrome, inflammatory bowel disease, functional dyspepsia, non-alcoholic fatty liver disease, alcoholic liver disease, cirrhosis and hepatic encephalopathy via the gut-liver-brain axis, and the focus is to clarify the potential mechanisms and treatment of digestive diseases based on the further understanding of the microbiota-gut- liver-brain axis.

Similarity and diversity of spontaneous brain activity in functional dyspepsia subtypes

BACKGROUND

Functional dyspepsia (FD) subtypes may differ in terms of pathophysiology, but the underlying mechanisms remain poorly understood.

PURPOSE

To explore spontaneous brain activity in two main FD subtypes, namely epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS), using the amplitude of low-frequency fluctuation (ALFF).

MATERIAL AND METHODS

Thirty-one FD patients (18 EPS and 13 PDS) and 22 matched healthy controls (HC) underwent resting-state functional MRI scanning. Spontaneous brain activity was evaluated by measuring the ALFF and then compared among the EPS, PDS, and HC groups with ANOVA test. Pearson correlation analysis was performed between the ALFF values and clinical indices.

RESULTS

Compared to healthy controls, both EPS and PDS patients had increased ALFF in the bilateral precentral/postcentral gyri, insula, and thalami. Furthermore, only the EPS patients displayed increased ALFF in the right middle and inferior frontal gyri, and only the PDS patients showed increased ALFF in the left posterior cingulate cortex (PCC). The ALFF values in the left thalamus were positively correlated with the sleep disturbance in EPS patients, and the ALFF values in the right precentral/postcentral gyri showed a positive correlation with the symptom score in PDS patients.

CONCLUSION

EPS and PDS had similarities of higher spontaneous brain activity in the primary motor/sensory areas and homeostatic-afferent network regions, and differences in the prefrontal region and PCC, providing evidence to suggest the similarity and diversity of pathophysiology in FD subtypes.

Suppressive effect of Aurantii Fructus Immaturus and Atractylodis Macrocephalae Rhizoma on glutamic acid-induced autophagy of interstitial cells of Cajal

OBJECTIVE

To investigate the effects of Aurantii Fructus Immaturus (Zhishi, ZS) and Atractylodis Macrocephalae Rhizoma (Baizhu, BZ)-containing serum on glutamate-induced autophagy in rat colonic interstitial cells of Cajal (ICCs) and to analyze the underlying mechanism.

METHODS

Rat colonic ICCs cultured in vitro were identified by fluorescence and then stimulated with glutamic acid (5 mmol/L) for 24 h to establish a cell model of autophagy. The cells were then treated with different concentrations of ZSBZ-containing serum or rat serum. The viability of the ICCs was detected with cell counting kit-8 assays, and cell apoptosis rates were examined with flow cytometry. The ultrastructure and autophagosomes in the ICCs were observed using transmission electron microscopy. The effects of ZSBZ-containing serum on apoptosis-associated mediators were assessed by Western blotting and real-time quantitative polymerase chain reaction. In addition, microtubule-associated protein light chain 3 (LC3), p-phosphoinositide 3-kinase (p-PI3K), p-Akt and p-mammalian target of rapamycin (p-mTOR) expression was detected via Western blotting analysis.

RESULTS

Compared to those in the model group, ICC viability and apoptosis rates were significantly increased by ZSBZ-containing serum (P < 0.05). In addition, the expression levels of Beclin-1, LC3, p-PI3K, p-Akt and p-mTOR were significantly lower (P < 0.05) and Bcl-2 expression was higher in the ZSBZ-containing serum treatment groups than in the model group (P < 0.05).

CONCLUSION

Our findings demonstrated that ZSBZ protects glutamic acid-stimulated ICCs, and this beneficial effect may be mediated by a reduction in autophagy via inhibition of the PI3K/Akt/mTOR pathway.

Effects and mechanisms of acupuncture and electroacupuncture for functional dyspepsia: A systematic review

BACKGROUND

Functional dyspepsia (FD) is a common digestive disease with limited therapeutic options. According to evidence-based clinical practice, acupuncture or electroacupuncture (EA) seems to be a promising therapy for patients with FD. However, there is still a lack of systematic reviews that have analyzed current clinical trials for a better understanding of mechanisms involved in the ameliorating effect of acupuncture and EA on FD.

AIM

To evaluate the results and qualities of existing clinical evidence for researching the underlying mechanisms of acupuncture/EA in treating FD.

METHODS

A systematic search of the literature was performed to identify randomized controlled trials in which research on the mechanism of acupuncture or EA was conducted in FD patients. Databases searched included PubMed, EMBASE, Cochrane Library, and Web of Science. Data extraction and quality assessment were completed by two investigators independently and the results of quality evaluation were exported through Review Manager V5.3.

RESULTS

Eight studies were included in this review with a total of 17 items for detecting techniques for mechanistic research. Positive effects of acupuncture and EA were observed in regulating gastric motility, gastric accommodation, mental status, gastrointestinal hormones, and central and autonomic functions while improving dyspeptic symptoms and quality of life.

CONCLUSION

The key findings of this systematic review support the potential of acupuncture and EA in altering the heterogeneous pathophysiology in patients with FD. However, high-quality studies with well-planned designs are necessary to provide more credible evidence.