Impaired duodenal mucosal integrity and low-grade inflammation in functional dyspepsia

Electroacupuncture improves low-grade duodenal inflammation in FD rats by reshaping intestinal flora through the NF-κB p65/NLRP3 pyroptosis pathway

Electroacupuncture (EA) is an effective alternative for the treatment of functional dyspepsia (FD). It reduces low-grade duodenal inflammation and improves the symptoms of FD by downregulating the expression of NF-κB p65 and NLRP3, but its mechanism needs to be elucidated. To examine the regulatory effect of electroacupuncture (EA) on intestinal flora and NF-κB p65/NLRP3 pyroptosis pathway in FD rats. The FD rat model was established via multi-factor stress intervention for two weeks. The rats were randomly divided into the NC group, model group, NF-kB inhibitor group (NF-κB inhibitor BAY 11-7082 was administered), EA group, and EA + NF-kB inhibitor group. After 14 days of treatment, the rats were sacrificed, and the protein and mRNA levels of NF-κB p65, IκB, and NLRP3 in the duodenum were evaluated by Western blotting assays and real-time fluorescent quantitative PCR. The Illumina MiSeq sequencing platform was used to analyze the V4 region of the 16S rRNA gene of intestinal flora and predict functional genes. The concentration of short-chain fatty acids (SCFAs) in feces was assessed by metabolomics. EA can decrease low-grade duodenal inflammation and promote gastrointestinal motility in FD rats. This effect is mediated by inhibition of the NF-κB p65/NLRP3 pyroptosis pathway, an increase in the alpha and beta diversity of gut microbiota in the duodenum, an increase in the abundance of beneficial bacteria at the phylum and genus levels, and an increase in the content of SCFAs. The protective effect of EA against FD might involve multiple hierarchy and pathways. EA may remodel intestinal flora by inhibiting the NF-κB p65/NLRP3 pyroptosis pathway, thereby improving low-grade duodenal inflammation in FD rats.

Postprandial symptoms in disorders of gut-brain interaction and their potential as a treatment target

Postprandial, or meal-related, symptoms, such as abdominal pain, early satiation, fullness or bloating, are often reported by patients with disorders of gut-brain interaction, including functional dyspepsia (FD) or irritable bowel syndrome (IBS). We propose that postprandial symptoms arise via a distinct pathophysiological process. A physiological or psychological insult, for example, acute enteric infection, leads to loss of tolerance to a previously tolerated oral food antigen. This enables interaction of both the microbiota and the food antigen itself with the immune system, causing a localised immunological response, with activation of eosinophils and mast cells, and release of inflammatory mediators, including histamine and cytokines. These have more widespread systemic effects, including triggering nociceptive nerves and altering mood. Dietary interventions, including a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols, elimination of potential food antigens or gluten, IgG food sensitivity diets or salicylate restriction may benefit some patients with IBS or FD. This could be because the restriction of these foods or dietary components modulates this pathophysiological process. Similarly, drugs including proton pump inhibitors, histamine-receptor antagonists, mast cell stabilisers or even tricyclic or tetracyclic antidepressants, which have anti-histaminergic actions, all of which are potential treatments for FD and IBS, act on one or more of these mechanisms. It seems unlikely that food antigens driving intestinal immune activation are the entire explanation for postprandial symptoms in FD and IBS. In others, fermentation of intestinal carbohydrates, with gas release altering reflex responses, adverse reactions to food chemicals, central mechanisms or nocebo effects may dominate. However, if the concept that postprandial symptoms arise from food antigens driving an immune response in the gastrointestinal tract in a subset of patients is correct, it is paradigm-shifting, because if the choice of treatment were based on one or more of these therapeutic targets, patient outcomes may be improved.

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

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Double-blind, randomized, 8-week multicenter study of the efficacy and safety of STW 5-IIversus placebo in functional dyspepsia

Background and Aim

Herbal products are widely used to treat patients with disorders of gut brain interaction but clinical efficacy and safety data for treatments lasting >4 weeks are widely lacking. We evaluated the efficacy and safety of 8 weeks of treatment with the herbal combination product STW 5-II for patients with functional dyspepsia (FD) meeting Rome II criteria. We also conducted a post hoc analysis including patients meeting Rome IV criteria for FD and evaluated the effect of the G-protein beta 3 (GNB3) subunit polymorphism (C825T) on therapeutic response.

Methods

This multicenter, placebo-controlled, double-blind study included 272 FD patients meeting Rome II criteria in the intention-to-treat cohort and 266 meeting Rome IV criteria. We used the validated Gastrointestinal Symptom Score (GIS) to assess GI symptoms, defining response rate as the proportion of patients with ≥50% GIS improvement in at least three of four assessments.

Results

After 8 weeks, the response rate was significantly higher in the STW 5-II group versus placebo (61.2% vs 45.1%, P = 0.008). Mean GIS non-significantly improved with STW 5-II treatment (7.9 ± 4.41 vs 6.7 ± 4.91 with placebo; P = 0.07). In the Rome IV subgroup analysis, STW 5-II yielded a better response rate (P = 0.01) versus placebo and greater postprandial distress symptom improvement (P = 0.04) versus placebo. Safety parameters did not differ between groups, and GNB3 status was not linked with therapeutic response.

Conclusion

STW 5-II is efficacious, with no observed safety signals at up to 8 weeks of treatment in patients with FD meeting Rome II or IV criteria.

Breaking the Barrier: The Role of Gut Epithelial Permeability in the Pathogenesis of Hypertension

PURPOSE OF THE REVIEW

To review what intestinal permeability is and how it is measured, and to summarise the current evidence linking altered intestinal permeability with the development of hypertension.

RECENT FINDINGS

Increased gastrointestinal permeability, directly measured in vivo, has been demonstrated in experimental and genetic animal models of hypertension. This is consistent with the passage of microbial substances to the systemic circulation and the activation of inflammatory pathways. Evidence for increased gut permeability in human hypertension has been reliant of a handful of blood biomarkers, with no studies directly measuring gut permeability in hypertensive cohorts. There is emerging literature that some of these putative biomarkers may not accurately reflect permeability of the gastrointestinal tract. Data from animal models of hypertension support they have increased gut permeability; however, there is a dearth of conclusive evidence in humans. Future studies are needed that directly measure intestinal permeability in people with hypertension.

Efficacy and safety of pinaverium bromide as an add-on therapy in refractory dyspepsia: A randomized controlled trial

Background and Aim

Functional dyspepsia (FD) remains a therapeutic challenge, and the efficacy of antispasmodic agents as adjunctive therapy is not well established. This study aimed to evaluate the efficacy and safety of pinaverium bromide added to omeprazole in treating refractory FD.

Methods

We conducted a randomized, placebo-controlled trial in patients with refractory dyspepsia. Participants were randomly assigned to receive pinaverium (50 mg, 3 times/day, n = 36) or placebo (n = 36) in addition to omeprazole for 8 weeks. The primary endpoint was the responder rate for adequate relief. Secondary outcomes included the Global Overall Symptom Scale (GOSS), quality of life, and safety profile.

Results

No statistically significant differences were observed in the adequate relief response rate between the pinaverium bromide and control group at week 2 (58.3% vs. 62.9%, P = 0.697), week 4 (62.9% vs. 78.1%, P = 0.173), week 6 (64.7% vs. 75.0%, P = 0.363), and week 8 (64.7% vs. 75.0%, P = 0.363). Additionally, there were no significant differences observed in the decline of symptom score between the two groups at week 4 (8.4 ± 7.6 vs. 7.7 ± 7.1, P = 0.702) and week 8 (10.9 ± 8.2 vs. 8.4 ± 7.2, P = 0.196). Similarly, there were no significant differences in terms of quality of life between the two groups. Adverse event rates were also comparable between the two groups.

Conclusion

Pinaverium bromide was found to be safe in the treatment of refractory dyspepsia, but it did not demonstrate a significant benefit in improving symptoms.

Transcutaneous Auricular Vagal Nerve Stimulation Is Effective for the Treatment of Functional Dyspepsia: A Multicenter, Randomized Controlled Study

INTRODUCTION

Vagal nerve stimulation (VNS) can be used to modulate gastrointestinal motility, inflammation, and nociception. However, it remains unclear whether VNS is effective in adult patients with functional dyspepsia (FD). We investigated the effectiveness of transcutaneous auricular VNS (taVNS) in patients with FD.

METHODS

Consecutive patients with FD meeting Rome IV criteria with modified FD Symptom Diary score ≥10 were enrolled. Patients were randomly allocated to 10-Hz taVNS (V10 group), 25-Hz taVNS (V25 group), or sham group, with 30 minutes of treatment twice a day for 4 weeks. The primary outcome was the response rate at week 4, defined as the proportion of patients whose modified FD Symptom Diary score was reduced ≥5 when compared with the baseline. Secondary outcomes included adequate relief rate and adverse events.

RESULTS

A total of 300 patients were randomized to V10 (n = 101), V25 (n = 99), and sham groups (n = 100). After 4 weeks of treatment, V10 and V25 groups had a higher response rate (81.2% vs 75.9% vs 47%, both P < 0.001) and adequate relief rate (85.1% vs 80.8% vs 67%, both P < 0.05) compared with the sham group. There was no significant difference between V10 and V25 in response rate and adequate relief rate (both P > 0.05). The efficacy of taVNS (both 10 and 25 Hz) lasted at week 8 and week 12 during follow-up period. Adverse events were all mild and comparable among the 3 groups (1%-3%).

DISCUSSION

Our study firstly showed that 4-week taVNS (both 10 and 25 Hz) was effective and safe for the treatment of adult FD ( clinicaltrials.gov number: NCT04668534).

The effects of Massa Medicata Fermentata on the digestive function and intestinal flora of mice with functional dyspepsia

Introduction: The purpose of this study was to identify the chemical components of Massa Medicata Fermentata (MMF) in different fermentation methods, analyze its regulatory effects on gastrointestinal propulsion and intestinal flora in mice with food accumulation, and further explore its mechanism of action in the treatment of dyspepsia. Methods: The chemical compositions of three kinds of MMF were identified using the UPLC-Q- Exactive Orbitrap mass spectrometer. A model of spleen deficiency and food accumulation in mice was established. The gastric emptying rate and intestinal propulsion rate were calculated, serum gastrin concentration and cholinesterase activity were measured, and 16S rRNA microbial detection was performed in different groups of mouse feces. Results: The results showed that a total of 95 chemical components were identified from the three MMF extracts, 62 of which were the same, but there were differences in flavonoids and their glycosides, organic acids, and esters. MMF, PFMMF, and commercial MMF could all significantly improve the gastric emptying rate, intestinal propulsion rate, and GAS concentration in the serum of model mice; PFMMF has a better effect, while there was no significant difference in cholinesterase activity among the groups (p > 0.05). The 16S rRNA sequencing results showed that the MMF and PFMMF could increase the content of beneficial bacteria Bacteroidetes and decrease the pathogenic bacteria Verrucomicrobia in the intestines of model mice, while the commercial MMF could not. Discussion: Studies suggest that MMF has a variety of possible mechanisms for improving food accumulation and treating gastrointestinal dyspepsia, which provides reference value for the quality evaluation and clinical application of MMF.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Screening of anti-functional dyspepsia compounds in Cynanchum auriculatum: A spectrum-effect relationship analysis, and ATP-binding cassette transporters inhibitor evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Functional dyspepsia (FD) is a disorder caused by abnormal gut-brain axis regulation and is highly prevalent in China. Cynanchum auriculatum (CA) is often used to treat FD in the ethnic minority areas of Guizhou. Although several CA-based products are currently available in the market, it is unclear which components of CA are efficacious and what their oral absorption mechanism is.

AIM OF THE STUDY

This study aimed to screen anti-FD components of CA based on the spectrum-effect relationship. In addition, the study evaluated the intestinal absorption mechanism of these components using transporter inhibitors.

MATERIALS AND METHODS

The fingerprinting of compounds from CA extract and plasma after oral administration was conducted using ultra-high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS). The intestinal contractile parameters were then measured in vitro using the BL-420F Biofunctional Experiment System. Multivariate statistical analysis of the result of spectrum-effect relationship assessment was used to elucidate the correlation between prominent peaks of CA-containing plasma and intestinal contractile activity. The effect of ATP-binding cassette (ABC) transporter inhibitors, such as the P-gp inhibitor verapamil, the MRR inhibitor indomethacin, and the BCRP inhibitor Ko143, on the directional transport of the predicted active ingredients was assessed in vivo.

RESULTS

Twenty chromatographic peaks were identified in the CA extract. Of these, three were C21 steroids, four were organic acids, and one was a coumarin, and acetophenone by comparing with reference compounds. Additionally, it is discovered that there are totally 39 migratory components in CA-containing plasma, which was found to significantly promote the contractility of the isolated duodenum. Moreover, multivariate analysis of the spectrum-effect relationship demonstrated that 16 characteristic peaks (3, 6, 8, 10, 11, 13, 14, 18, 21, m1-m4, m7, m15, and m24) in CA-containing plasma were significantly associated with the anti-FD effect. These compounds included seven prototype compounds, i.e., cynanoneside A, syringic acid, deacylmetaplexigenin, ferulic acid, scopoletin, baishouwubenzophenone, and qingyangshengenin. The inhibition of ABC transporters demonstrated that the inhibitors verapamil and Ko143 significantly increased (P < 0.05) the uptake of scopoletin and qingyangshengenin. Thus, these compounds may be substrates for P-gp and BCRP.

CONCLUSIONS

The potential anti-FD components of CA and the effect of ABC transporter inhibitors on these active components were preliminarily clarified. These findings lay a foundation for subsequent in vivo studies.

Nutrition and Disorders of Gut-Brain Interaction

BACKGROUND

Disorders of gut-brain interaction (DGBIs) have a complex pathophysiology that is often characterized by a relationship between food ingestion and triggering of symptoms. Understanding of the underlying mechanisms and the role of nutrients as a therapeutic target are rapidly evolving.

AIMS AND METHODS

We performed a narrative review of the literature using the following keywords, their acronyms, and their associations: nutrients, disorders of gut-brain interaction; functional dyspepsia; malabsorption; irritable bowel syndrome; diarrhea; constipation.

RESULTS

Functional dyspepsia displayed a significant correlation between volume, fat and/or wheat abundance, chemical composition of ingested food and symptoms of early satiety, fullness and weight loss. Carbohydrate malabsorption is related to enzyme deficiency throughout the GI tract. Food composition and richness in soluble vs. non-soluble fibers is related to constipation and diarrhea. The elimination of fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) has a significant and non-unidirectional impact on irritable bowel syndrome (IBS) symptoms.

CONCLUSIONS

Food volume, nutritive and chemical composition, and its malabsorption are associated with symptom generation in DGBIs. Further multicenter, randomized-controlled clinical trials are needed to clarify the underlying pathophysiology.

Correlation between anxiety and decreased quality of life in patients with non-esophageal eosinophilic gastrointestinal diseases

Background and Aim

Mental status such as anxiety and depression in patients with non-esophageal eosinophilic gastrointestinal diseases (non-EoE EGIDs) has not been studied. The aim of this study was to evaluate whether patients with non-EoE EGIDs had mental disorders and decreased mental-health-related quality of life (QOL) similar to those in patients with disorders of gut-brain interaction (DGBI).

Methods

We enrolled patients with non-EoE EGIDs and DGBI visiting the Osaka Metropolitan University Hospital, and the measures listed below were compared between the groups. We collected data using the following questionnaires: hospital anxiety and depression scale, and short form (SF)-8 including mental component summary (MCS)-8.

Results

We evaluated 21 and 17 patients with non-EoE EGIDs and DGBI, respectively. The anxiety score was not significantly different between the groups. The proportion of patients with possible anxiety was not significantly different between the groups (19.0% vs 33.3%). These results show that patients with non-EoE EGIDs had anxiety that might be equivalent to that of patients with DGBI. The depression score and proportion of patients with possible depression in the non-EoE EGID group tended to be lower than those in the DGBI group. MCS-8 scores were not significantly different between the non-EoE EGID and DGBI groups, which might imply an equivalent decrease in mental-health-related QOL in both groups of patients. In patients with non-EoE EGIDs, the anxiety score had a significant inverse association with the MCS-8 score.

Conclusions

Patients with non-EoE EGIDs may have anxiety that correlates with decreased mental-health-related QOL.

Surface layer proteins from Lactobacillus helveticus ATCC® 15009™ affect the gut barrier morphology and function

Paraprobiotics and postbiotics represent a valid alternative to probiotic strains for ameliorating and preserving a healthy intestinal epithelial barrier (IEB). The present study investigated the effects of surface layer proteins (S-layer) of the dairy strain Lactobacillus helveticus ATCC® 15009™ (Lb ATCC® 15009™), as paraprobiotic, on the morpho-functional modulation of IEB in comparison to live or heat-inactivated Lb ATCC® 15009™ in an in vitro co-culture of Caco-2/HT-29 70/30 cells. Live or heat-inactivated Lb ATCC® 15009™ negatively affected transepithelial electrical resistance (TEER) and paracellular permeability, and impaired the distribution of Claudin-1, a tight junction (TJ) transmembrane protein, as detected by immunofluorescence (IF). Conversely, the addition of the S-layer improved TEER and decreased permeability in physiological conditions in co-cultures with basal TEER lower than 50 ohmcm2, indicative of a more permeable physiological IEB known as leaky gut. Transmission electron microscopy (TEM) and IF analyses suggested that the S-layer induces a structural TJ rearrangement and desmosomes' formation. S-layer also restored TEER and permeability in the presence of LPS, but not of a mixture of pro-inflammatory cytokines (TNF-α plus IFN-γ). IF analyses showed an increase in Claudin-1 staining when LPS and S-layer were co-administered with respect to LPS alone; in addition, the S-layer counteracted the reduction of alkaline phosphatase detoxification activity and the enhancement of pro-inflammatory interleukin-8 release both induced by LPS. Altogether, these data corroborate a paraprobiotic role of S-layer from Lb ATCC® 15009™ as a possible candidate for therapeutic and prophylactic uses in conditions related to gastrointestinal health and correlated with extra-intestinal disorders.

Electroacupuncture restores intestinal mucosal barrier through TLR4/NF-κB p65 pathway in functional dyspepsia-like rats

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with high morbidity. Electroacupuncture (EA) has been applied to treat FD for a long time. The aim of this study was to investigate the effects of EA and its mechanism about intestinal mucosal barrier in rodent model of FD. Male Sprague-Dawley rats were randomly divided into the control group and the model group. Then, the rats in model group were established to the FD model by multifactor interventions. In Experiment 1, qualified FD-like rats were randomly divided into three groups: FD, EA, and acupuncture (AP) groups. The interventions of EA and AP lasted 14 days, food intake, and body weight were recorded every 5 days. In Experiment 2, qualified FD-like rats were randomly divided into five groups: FD, EA, AP, EA + TAK242, and TAK242 groups. The interventions of EA and AP lasted 14 days, while TAK242 injection continued for 6 days. The rats were sacrificed for the measurement of serum Interleukin- 6 (IL-6) and Tumor necrosis factor-α (TNF-α) assayed by ELISA. Western blotting was used to assess the expression of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6, ZO-1, and occludin in the duodenum. The transmission electron microscope was used to observe the ultrastructure of intestinal epithelial cells. Compared with the rats in the group FD, the rats in EA group had significantly increase of body weight, food intake, and protein expressions of ZO-1 and occludin, while expressions of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6 in the duodenum and IL-6, and TNF-α in serum were decreased. The EA + TAK242 treatment had similar effects to the EA treatment but with increased potency; compared with EA, AP showed similar but reduced effects. Our data demonstrated that EA is more effective than AP in improving intestine mucosal barrier. The possible mechanisms of EA may involve the TLR4/NF-κB p65 pathway.

Non-invasive neuromodulation: an emerging intervention for visceral pain in gastrointestinal disorders

Gastrointestinal (GI) disorders, which extend from the esophagus to the anus, are the most common diseases of the GI tract. Among these disorders, pain, encompassing both abdominal and visceral pain, is a predominant feature, affecting the patients' quality of life and imposing a substantial financial burden on society. Pain signals originating from the gut intricately shape brain dynamics. In response, the brain sends appropriate descending signals to respond to pain through neuronal inhibition. However, due to the heterogeneous nature of the disease and its limited pathophysiological understanding, treatment options are minimal and often controversial. Consequently, many patients with GI disorders use complementary and alternative therapies such as neuromodulation to treat visceral pain. Neuromodulation intervenes in the central, peripheral, or autonomic nervous system by alternating or modulating nerve activity using electrical, electromagnetic, chemical, or optogenetic methodologies. Here, we review a few emerging noninvasive neuromodulation approaches with promising potential for alleviating pain associated with functional dyspepsia, gastroparesis, irritable bowel syndrome, inflammatory bowel disease, and non-cardiac chest pain. Moreover, we address critical aspects, including the efficacy, safety, and feasibility of these noninvasive neuromodulation methods, elucidate their mechanisms of action, and outline future research directions. In conclusion, the emerging field of noninvasive neuromodulation appears as a viable alternative therapeutic avenue for effectively managing visceral pain in GI disorders.

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.

Endoscopic laser endomicroscopy and "leaky gut" in patients with functional gastrointestinal symptoms and food intolerance

BACKGROUND

Intestinal epithelial barrier dysfunction ("leaky gut syndrome", LGS) is thought to play a major role in the pathogenesis of disorders of the gut brain axis. Endoscopic confocal laser endomicroscopy (eCLE) is an objective measure to test duodenal permeability. We applied this technique in patients with functional gastrointestinal symptoms and food intolerance to characterize the proportion of patients with LGS.

MATERIAL AND METHODS

In an observational study, we evaluated 85 patients with functional gastrointestinal symptoms and food intolerance. Gastrointestinal symptoms were classified according to Rom IV into functional abdominal pain (FAP), irritable bowel syndrome (IBS), irritable bowel syndrome diarrhea dominant (IBS-D), irritable bowel syndrome constipation dominant (IBS-C), irritable bowel syndrome with mixed stool (IBS-M), functional abdominal bloating (FAB), functional diarrhea (FD) and unclassified (NC). During eCLE, spontaneous transfer of intravenously applied fluorescein into duodenal lumen (LGS) and following duodenal food challenge (DFC) were analyzed. Blood analysis comprised parameters of mast cell function, histology of duodenal mucosal biopsies analysis of mucosal inflammation, intraepithelial lymphocytes (IELs) as well as number, distribution and morphology of mast cells.

RESULTS

24 patients (9 IBS, 9 FAP, 3 FAB, 1 FD, 2 NC), showed LGS, 50 patients (14 IBS-D, 4 IBS-C, 3 IBS-M, 23 FAP, 3 FAB, 3 NC) had no LGS but responded to DFC and 11 patients (6 NC, 3 FAP, 1 FAB, 1 FD) had no LGS and no response to DFC. The proportion of subgroups with/or without spontaneous leakage of fluorescein (+LGS/-LGS) were IBS-LGS/IBS+LGS 67%/33%, FAP-LGS/FAP+LGS 72%/28%,FAB-LGS/FAB+LGS 50%/50%, NC-LGS/NC+LGS 60%/40%. Subgroup analysis revealed no significant differences for all parameters tested.

CONCLUSION

As a proof of concept, the results of our study indicate that eCLE is a clinical useful tool to evaluate patients with disorders of the gut brain axis and those suspicious of LGS. However, the clinical significance of LGS remains unclear. The study should be an incentive to perform a randomized study including healthy controls.

Eosinophil and mast cell-derived exosomes promote integrity of intestinal mucosa via the NEAT1/miR-211-5p/glial cell line-derived neurotrophic factor axis in duodenum

BACKGROUND

Exosomes are applied as biomarkers in several diseases according to their disease-specific profiles. However, the exosomes effects in functional dyspepsia (FD) are still fragmentary. Here we examined the role of Eosinophil and mast cell derived-exosomes in FD progression.

METHODS

Fifty FD subjects and age- and sex-matched healthy controls were included in this retrospective cohort study. Duodenal mucosa and gastric juice were collected to analyze molecular difference. Eosinophil and mast cell were evaluated by immunofluorescence and microarray was subjected to examine the expression levels of NEAT1, miR-211-5p, and glial cell line-derived neurotrophic factor (GDNF), which were subsequently were tested by quantitative reverse transcription PCR (RT-qPCR) validation cohorts. CCK-8 assays, and wound healing assays were used to evaluate integrity of intestinal mucosal barrier in vitro. Rats' weights and gastric emptying rates were used as evaluation of FD severity in vivo.

RESULTS

Eosinophil and mast cell were enriched and secreted more exosomes in duodenal mucosa of FD patients. We identified differential lncRNAs that were consistently and significantly up regulated in FD cases. Of these, NEAT1 was further validated by RT-qPCR and had closely relationship with GDNF. MiR-211-5p level was found to be reduced in FD and negatively related with NEAT1 and GDNF. Furthermore, NEAT1and GDNF relived FD while miR-211-5p made symptoms worse. The NEAT1/miR-211-5p/GDNF axis had a good predictive ability for FD.

CONCLUSIONS

The NEAT1/miR-211-5p/GDNF could be a potential FD biomarker.

Clinical Efficacy and Mechanism of Transcutaneous Neuromodulation on Functional Dyspepsia

BACKGROUND AND AIMS

Prokinetics and proton pump inhibitors are first-line drugs for functional dyspepsia (FD) patients. However, no available treatment is effective for most FD patients, and the pathogenesis is still unclear. The purpose of this study was to investigate the therapeutic effect of transcutaneous neuromodulation (TN) on FD and its potential mechanisms.

MATERIALS AND METHODS

Fifty-seven FD patients were enrolled in the study and randomly divided into 3 groups (TN Neiguan (PC6) group, TN Zusanli (ST36) group, and sham TN group) that received corresponding treatment respectively for 4 weeks. Then, all the patients enrolled received TN PC6 combined with ST36 treatment for another 4 weeks. Dyspepsia symptom questionnaire, Medical outcomes study item short form health survey (SF-36), Hospital Anxiety and Depression Scale were used to assess the severity of symptoms. Gastric accommodation, gastric emptying rate, and related parameters of electrogastrogram were used to assess the pathophysiological mechanism of FD. The possible gastrointestinal hormonal mechanism involved was assessed by detecting serum ghrelin, neuropeptide Y, and vasoactive intestinal peptide. The possible duodenal inflammation mechanism involved was assessed by detecting duodenal mucosa.

RESULTS

TN treatment reduced the dyspepsia symptom score ( P <0.05) and improved the quality of life. After TN treatment, the gastric accommodation ( P <0.01), the gastric emptying rate ( P <0.01), and the percentages of preprandial ( P <0.05) and postprandial ( P <0.05) gastric slow waves (GSW) were increased. The proportions of preprandial ( P <0.05) and postprandial ( P <0.05) gastric electrical rhythm disorder were reduced. The double acupoint combination therapy further enhanced the therapeutic effect of single acupoint. In addition, the levels of ghrelin ( P <0.001) and neuropeptide Y ( P <0.001) were significantly increased, the level of vasoactive intestinal peptide ( P <0.001) was significantly decreased, and the total number of mast cells ( P <0.001) in the duodenal bulb was significantly decreased after double acupoints combination therapy.

CONCLUSIONS

TN treatment significantly improves the dyspepsia symptoms of FD patients and their quality of life. TN treatment increases the percentage of normal GSW, reduces the proportion of gastric electrical rhythm disorder, and improves the gastric accommodation and gastric emptying rate. The therapeutic effect of TN may be caused by regulating gastrointestinal hormone secretion and alleviating local inflammatory responses in duodenum. In addition, the improvement of TN on GSW was closely related to the decrease of bradygastria.

Cigarette Smoke Mediates Nasal Epithelial Barrier Dysfunction via TNF-α

BACKGROUND

Extensive data suggest that exposure to cigarette smoke can induce pulmonary epithelial barrier dysfunction. However, the effects of cigarette smoke on the nasal epithelial barrier are still unclear. Here, we investigated the consequence and mechanism of cigarette smoke on the nasal epithelial barrier.

METHODS

Sprague Dawley rats were exposed to cigarette smoke for 3 or 6 months, and changes in inflammatory markers and nasal barrier function were evaluated. Moreover, underlying mechanisms were explored. Finally, normal human bronchial epithelial cells were cultured with or without tumor necrosis factor-alpha (TNF-α) in vitro, and the levels of continuity and tight junction-associated proteins were measured.

RESULTS

In vivo experiments showed that the nasal mucosal barrier function of rats exposed to cigarette smoke was disturbed. Indeed, proteins associated with tight junctions were decreased, and the levels of inflammatory factors, such as IL-8, IL-6, and TNF-α, were dramatically increased in comparison to those of control animals. In vitro, TNF-α was shown to disrupt the continuity of proteins associated with tight junctions and to downregulate the expression of these proteins in bronchial epithelial cells.

CONCLUSIONS

We found that cigarette smoke disrupted the nasal mucosal barrier, and the extent of the damage was correlated with the duration of cigarette smoke exposure. We showed that TNF-α can disrupt the continuity and attenuate the expression of tight junction proteins in human bronchial epithelial cells. Therefore, cigarette smoke may induce nasal epithelial barrier dysfunction through TNF-α.

Association between genetic polymorphisms of NOD1, Interleukin-1B, and cagA strain with low-grade duodenal eosinophilia in Helicobacter pylori-related dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a multifactorial disorder. Helicobacter pylori (H. pylori)-related dyspepsia (HpD) may be considered a separate entity. Duodenal eosinophilia is a potential pathogenic mechanism in FD. However, the impact of duodenal eosinophilia and host genetic polymorphism of innate and pro-inflammatory cascade, nucleotide-binding oligomerization domain 1 (NOD-1), and interleukin-1 beta (IL-1β) in HpD was not explored.

AIM

To evaluate the association of NOD1-796G>A and IL-1B-511C>T gene variants and low-grade duodenal eosinophilia in HpD.

METHODS

A multicenter cross-sectional study was conducted. A total of 253 patients who met Rome-IV criteria were selected before upper endoscopy and 98 patients were included after unremarkable upper endoscopy and positive H. pylori in gastric biopsies were assessed. Clinical parameters, H. pylori cagA and duodenal histology, were evaluated.

RESULTS

Sixty-four (65%) patients had epigastric pain syndrome (EPS), 24 (25%) postprandial distress syndrome (PDS), and 10 (10%) EPS/PDS overlap. FD subtypes were not associated with NOD1-796G>A and IL-1B-511C>T gene variants. Low-grade duodenal eosinophilia was significantly increased in NOD1-796 GG versus single A-allele, but not in IL-1B-511 single T-allele or CC-allele. This association is dependent of cagA infection, since harboring cagA strain was significantly associated with low-grade duodenal eosinophilia with isolated variants NOD1-796 GG and IL-1B-511 single T-allele, but not without cagA. When we performed combined polymorphism analysis with NOD1-796 GG/IL-1B-511 single T-allele, a synergistic effect on low-grade duodenal eosinophilia was found between these two loci irrespective of cagA strain status in HpD.

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is significantly associated with NOD1-796 GG allele specially in cagA strain and with allelic combination NOD1-796 GG/IL-1B-511 single T-allele independent of cagA strain infection in HpD patients.

Regional changes in intestinal permeability in cirrhosis are associated with mucosal bacteria

BACKGROUND

Several complications of cirrhosis are theorized to result from the translocation of bacteria or their products across the intestinal epithelium. We aimed to assess epithelial permeability and associations with mucosal bacteria in patients with cirrhosis.

APPROACH AND RESULTS

We collected 247 duodenum, ileum, and colon biopsies from 58 consecutive patients with cirrhosis and 33 controls during clinically indicated endoscopies. Patients with cirrhosis were similarly aged to controls (60 vs. 58 y) and had a median Model for End-stage Liver Disease of 8 (interquartile range 7, 10). Biopsies underwent 16S rRNA-encoding gene amplicon sequencing to determine mucosal bacteria composition and transepithelial electrical resistance (TEER) to determine epithelial permeability. In the entire cohort, there were regional differences in TEER with the lowest TEER (ie, more permeable) in the ileum; duodenum TEER was 43% higher and colon TEER 20% higher than ileum TEER (ANOVA p = 0.0004). When comparing patients with cirrhosis and controls, both TEER (26% lower in cirrhosis, p = 0.006) and alpha diversity differed in the duodenum (27% lower in cirrhosis, p = 0.01) but not ileum or colon. A beta-binomial model found that 26 bacteria were significantly associated with TEER. Bifidobacteriaceae Bifidobacterium in duodenal mucosa was protective of epithelial permeability and future hospitalization for hepatic decompensation.

CONCLUSIONS

Duodenal epithelial permeability was higher, and mucosal bacteria alpha diversity was lower in cirrhosis compared to controls, while no such differences were seen in the ileum or colon. Specific bacteria were associated with epithelial permeability and future hepatic decompensation.

Effect of Rebamipide on the Intestinal Barrier, Gut Microbiota Structure and Function, and Symptom Severity Associated with Irritable Bowel Syndrome and Functional Dyspepsia Overlap: A Randomized Controlled Trial

Treatment of functional digestive disorders is not always effective. Therefore, a search for new application points for potential drugs is perspective. Our aim is to evaluate the effect of rebamipide on symptom severity, intestinal barrier status, and intestinal microbiota composition and function in patients with diarrheal variant of irritable bowel syndrome overlapping with functional dyspepsia (D-IBSoFD). Sixty patients were randomized to receive trimebutine (TRI group), trimebutine + rebamipide (T + R group), or rebamipide (REB group) for 2 months. At the beginning and end of the study, patients were assessed for general health (SF-36), severity of digestive symptoms (Gastrointestinal Symptom Rating and 7 × 7 scales), state of the intestinal barrier, and composition (16S rRNA gene sequencing) and function (short-chain fatty acid fecal content) of the gut microbiota. The severity of most digestive symptoms was reduced in the REB and T + R groups to levels similar to that observed in the TRI group. The duodenal and sigmoidal lymphocytic and sigmoidal eosinophilic infiltration was decreased only in the REB and T + R groups, not in the TRI group. Serum zonulin levels were significantly decreased only in the REB group. A decrease in intraepithelial lymphocytic infiltration in the duodenum correlated with a decrease in the severity of rumbling and flatulence, while a decrease in infiltration within the sigmoid colon correlated with improved stool consistency and decreased severity of the sensation of incomplete bowel emptying. In conclusion, rebamipide improves the intestinal barrier condition and symptoms in D-IBSoFD. The rebamipide effects are not inferior to those of trimebutine.

Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) are an extremely common set of more than 50 disorders characterized by persistent and recurring gastrointestinal symptoms. Most of these patients can be diagnosed and managed by primary care physicians. Treatment includes patient education and reassurance, eliminating triggers, dietary modification, and pharmacologic management. Primary care physicians should consider referral to gastroenterologists when patients exhibit red flag symptoms such as blood in stool, abnormal laboratory findings, involuntary weight loss, age of presentation greater than 50 years, or certain concerning family history.

Functional Dyspepsia: Current Understanding and Future Perspective

BACKGROUND

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

SUMMARY

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

KEY MESSAGES

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

Association of mental health conditions and functional gastrointestinal disorders among Vietnamese new-entry medical students

BACKGROUND

Functional gastrointestinal disorders (FGIDs), also known as disorders of gut-brain interaction, occur not only in the elderly but also in young adults. This study aimed to evaluate the association between mental health conditions and FGIDs among Vietnamese new-entry medical students.

METHODS

This cross-sectional study was conducted in February 2022 among new-entry medical students in Ho Chi Minh City, Vietnam. A printed questionnaire was distributed to all students on the day of freshmen health screening. Their urine samples were collected to screen for Helicobacter pylori infection using rapid urinary test. FGIDs were diagnosed using ROME IV criteria. Gastroesophageal reflux disease (GERD) was defined as the presence of typical reflux symptoms at least twice a week. Mental health conditions, including generalized anxiety disorder (GAD) and major depressive disorder (MDD), were identified using Generalized Anxiety Disorder Assessment-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) scales, respectively.

RESULTS

Among 400 new-entry medical students who participated in the study, the overall prevalence of FGIDs was 10.3% (functional dyspepsia 6.5%, irritable bowel disease 5.5%). The overlap syndrome (OS) of GERD-FGIDs or different FGIDs was present in 3.0% of participants. The prevalences of GAD and MDD were 6.8% and 10.2%, respectively. The urinary test was positive in 180 (45.0%) participants. In the multivariable logistic regression analysis, MDD was significantly associated with not only the risk of FGIDs (OR = 5.599, 95%CI: 2.173-14.430, p<0.001) but also the risk of OS (OR = 10.076, 95CI%: 2.243-45.266, p = 0.003).

CONCLUSIONS

MDD is associated with FGIDs and OS among new-entry medical students.

Proton pump inhibitors may enhance the risk of digestive diseases by regulating intestinal microbiota

Proton pump inhibitors (PPIs) are the most used acid-inhibitory drugs, with a wide range of applications in the treatment of various digestive diseases. However, recently, there has been a growing number of digestive complications linked to PPIs, and several studies have indicated that the intestinal flora play an important role in these complications. Therefore, developing a greater understanding of the role of the gut microbiota in PPI-related digestive diseases is essential. Here, we summarize the current research on the correlation between PPI-related digestive disorders and intestinal flora and establish the altered strains and possible pathogenic mechanisms of the different diseases. We aimed to provide a theoretical basis and reference for the future treatment and prevention of PPI-related digestive complications based on the regulation of the intestinal microbiota.

Exploring the potential targets of Biling Weitong Granules on visceral hypersensitivity through integration of network pharmacology and in vivo analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Biling Weitong Granules(BLWTG) are a newly developed traditional Chinese medicine prescription based on the ancient prescription Jinlingzi San and Zuojin Wan. It is used for the treatment of functional gastrointestinal disorders (FGIDs) featured as visceral hypersensitivity(VH). However, its active ingredients and protein targets involved still remain unknown.

AIM OF THE STUDY

To explore the potential targets of BLWTG for the treatment of visceral hypersensitivity.

MATERIALS AND METHODS

Active components and their protein targets of BLWTG were screened from TCMSP database and the component-target network were constructed with Cytoscape software. Irritable bowel syndrome (IBS) was the representative disease in this study and information on its linked pathways was obtained from NCBI, Drugbank and Genecard. Target pathways of BLWTG were analyzed through KEGG to verify the correlation with IBS related pathways.Then, the VH mouse models was induced by maternal separation(MS), randomly divided into normal saline(NS),BLWTG1(low-dosage) and BLWTG2(high-dosage) group. After intervention, threshold intensity of colorectal distension (CRD) and body weight were measured to evaluate relief of IBS symptoms. Elisa was performed to evaluate 5-HT concentration changes of colon tissues. Flow cytometry was performed to assess changes of colon eosinophils and mast cells proportion. Transcriptome sequencing was employed to analyze changes of pathways and differential genes.

RESULTS

199 protein targets and 132 active components of BLWTG were identified. KEGG analysis revealed the overlap between BLWTG target pathways and IBS related pathways such as neuroactive ligand-receptor interaction, tryptophan metabolism and inflammatory reaction. 34 genes were not only BLWTG target proteins but also recognized targets for treating IBS. After maternal separation(MS), the mice showed a significant decrease in threshold intensity of CRD, a progressive decrease in body weight and an increase of 5-HT concentration of colon tissue. The proportion of mast cells and eosinophils in the colon increased. Differential genes including Hp,Ido1 and Aqp7 were significantly increased in MS mice group and IBS-related pathways were upregulated. After treatment of BLWTG, threshold intensity of CRD and body weight were significantly improved and IBS related pathways were downregulated. In addition, among BLWTG protein targets, Il1b,Tnf,Adrb1 and Nos2 were found upregulated in MS + NS mice and downregulated after BLWTG intervention through combination of transcriptome sequencing.

CONCLUSIONS

In maternal separation-induced mouse models, BLWTG could alleviate visceral hypersensitivity, possibly through downregulation of 5-HT concentration and eosinophils and mast cells proportion in colon and critical pathways such as neuroactive ligand-receptor pathway. Potential targets of BLWTG including Il1b,Tnf,Adrb1 and Nos2 were found through integration of network pharmacology database and transcriptome sequencing, providing evidence for further study on mechanisms underlying visceral hypersensitivity.

Impact of Probiotics on the Prevention and Treatment of Gastrointestinal Diseases in the Pediatric Population

Despite the high prevalence of gastrointestinal disorders (GIDs) in infants and children, especially those categorized as functional GIDs (FGIDs), insufficient knowledge about their pathophysiology has limited both symptomatic diagnosis and the development of optimal therapies. Recent advances in the field of probiotics have made their potential use as an interesting therapeutic and preventive strategy against these disorders possible, but further efforts are still needed. In fact, there is great controversy surrounding this topic, generated by the high variety of potential probiotics strains with plausible therapeutic utility, the lack of consensus in their use as well as the few comparative studies available on probiotics that record their efficacy. Taking into account these limitations, and in the absence of clear guidelines about the dose and timeframe for successful probiotic therapy, our review aimed to evaluate current studies on potential use of probiotics for the prevention and treatment of the most common FGIDs and GIDs in the pediatric population. Furthermore, matters referring to know major action pathways and key safety recommendations for probiotic administration proposed by major pediatric health agencies shall also be discussed.

Overlap of disorders of gut-brain interaction: a systematic review and meta-analysis

BACKGROUND

Rome criteria differentiate distinct types of disorders of gut-brain interaction (DGBI); also known as functional gastrointestinal disorders. Overlap of symptom categories frequently occurs. This systematic review and meta-analysis aimed to define the prevalence of DGBI overlap and compare overlap in population-based, primary care or tertiary care health settings. Furthermore, we aimed to compare symptom severity of psychological comorbidities in DGBI with and without overlap.

METHODS

For this systematic review and meta-analysis we searched MEDLINE (PubMed) and Embase electronic databases from inception until March 1, 2022, for original articles and conference abstracts of observational cross-sectional, case-controlled, or cohort design studies that reported the prevalence of DGBI overlap in adult participants (aged ≥18 years). We included only those studies where the diagnosis of DGBI was based on clinical assessment, questionnaire data, or specific symptom-based criteria. Studies were excluded if reporting on mixed populations of DGBI and organic diseases. Aggregate patient data were extracted from eligible published studies. The prevalence of DGBI overlap in all studies was pooled using the DerSimonian and Laird random effects model, and further analysis stratified by subgroups (care setting, diagnostic criteria, geographic region, and gross domestic product per capita). We also assessed the relationship between DGBI overlap with anxiety, depression, and quality of life symptom scores. This study was registered with PROSPERO (CRD42022311101).

FINDINGS

46 of 1268 screened studies, reporting on 75 682 adult DGBI participants, were eligible for inclusion in this systematic review and meta-analysis. Overall, 24 424 (pooled prevalence 36·5% [95% CI 30·7 to 42·6]) participants had a DGBI overlap, with considerable between-study heterogeneity (I²=99·51, p=0·0001). In the tertiary health-care setting, overlap among participants with DGBI was more prevalent (8373 of 22 617, pooled prevalence 47·3% [95% CI 33·2 to 61·7]) compared with population-based cohorts (11 332 of 39 749, pooled prevalence 26·5% [95% CI 20·5 to 33·4]; odds ratio 2·50 [95% CI 1·28 to 4·87]; p=0·0084). Quality of life physical component scores were significantly lower in participants with DGBI overlap compared with participants without overlap (standardised mean difference -0·47 [95% CI -0·80 to -0·14]; p=0·025). Participants with DGBI overlap had both increased symptom scores for anxiety (0·39 [95% CI 0·24 to 0·54]; p=0·0001) and depression (0·41 [0·30 to 0·51]; p=0·0001).

INTERPRETATION

Overlap of DGBI subtypes is frequent, and is more prevalent in tertiary care settings and associated with more severe symptom manifestations or psychological comorbidities. Despite the large sample size, the comparative analyses revealed substantial heterogeneity, and the results should be interpreted with caution.

FUNDING

National Health and Medical Research Council and Centre for Research Excellence.

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.

The efficacy of dupilumab in induction and maintenance of remission in an adult patient with steroid-dependent eosinophilic enteritis (EoN)

Eosinophilic enteritis (EoN) is associated with an eosinophilic infiltrate confined to the small intestine, but treatment options other than diet and corticosteroid therapy are scarce. There is only one report of the use of dupilumab for eosinophilic gastrointestinal disease, involving three pediatric patients. We report a case of successful induction of remission with dupilumab in a 53 year-old female patient with steroid-dependent EoN. The patient presented to the emergency room with uncontrollable abdominal pain and CT revealed a thickened ileal wall and small amount of ascites. Despite no abnormalities on endoscopy, histological examination revealed numerous eosinophilic infiltrates (> 100/HPF) and degranulation in the ileal lamina propria, diagnosing the patient with EoN. The patient achieved clinical remission with prednisolone, but EoN relapsed during tapering. Long-term steroid therapy was inappropriate due to mandibular osteomyelitis and osteoporosis, and she was switched to 9 mg budesonide, an intestine-soluble topical steroid without effect. Dupilumab administration resulted in resolution of abdominal pain, and remission was maintained after discontinuation of budesonide. Histological remission was confirmed 2 months after dupilumab administration. This is the first report of remission induced and maintained with dupilumab in an adult patient with EoN.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Clinical Implications of Low-grade Duodenal Eosinophilia in Functional Dyspepsia: A Prospective Real-life Study

BACKGROUND

Functional dyspepsia (FD) is a multifactorial disorder with no targeted therapy. Duodenal eosinophilia and low-grade inflammation are potential pathogenic mechanisms. However, the impact of duodenal eosinophils (D-EO) histologic evaluation in real-life clinical practice was not explored.

AIM

To evaluate the clinical utility of D-EO and low-grade inflammation in FD in real-life practice.

MATERIALS AND METHODS

A multicenter prospective study was conducted. A total of 636 patients who meet Rome-III criteria were selected before upper endoscopy and 516 patients were included after normal endoscopy were assessed. Clinical parameters, Helicobacter pylori ( H. pylori), and duodenal histology were evaluated.

RESULTS

FD subtypes were 231 (45%) patients who had epigastric pain syndrome (EPS), 168 (33%) postprandial distress syndrome (PDS), and 117 (22%) EPS/PDS overlap. Two hundred fifty-nine (50.3%) patients were H. pylori+ . Histologic duodenal grading of chronic inflammation and intraepithelial lymphocytes showed no difference between FD subtypes. Increased in D-EO densities (>10 per high power field) was significant in PDS compared with EPS and EPS/PDS overlap subtypes. The odds ratio of PDS in subjects with duodenal eosinophilia densities was 2.28 (95% CI, 1.66-3.14; P <0.0001), adjusting for age, gender, H. pylori and nonsteroidal anti-inflammatory drug the odds ratio was 3.6 (95% CI, 2.45-5.28; P <0.0001). receiver operating characteristic curve analysis further demonstrated that low-grade duodenal eosinophilia, in particular H. pylori- , was highly accurate for PDS with the area under the curve 0.731 compared with H. pylori+ area under the curve 0.598. Furthermore, low-grade duodenal eosinophilia was significantly correlated with treatment response under 4 to 6 weeks of proton pump inhibitor therapy.

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is associated with PDS subtype non- H. pylori FD patients and could be a useful marker of treatment response.

[Frequent Gastro-Intestinal Disorders: Management of Functional Dyspepsia and Irritable Bowel Syndrome in Clinical Practice]

Frequent Gastro-Intestinal Disorders: Management of Functional Dyspepsia and Irritable Bowel Syndrome in Clinical Practice Abstract: Functional dyspepsia (FD) and irritable bowel syndrome (IBS), two common gastrointestinal entities with overlapping symptoms, should be diagnosed according to Rome IV criteria. This includes one or more of the following symptoms: in FD, postprandial fullness, early satiation, epigastric pain or burning; in IBS, recurrent abdominal pain associated with defecation, change in frequency of stool or form of stool. To exclude structural diseases, attention should be paid to alarm symptoms. As far as treatment is concerned, a stepwise scheme proves to be effective for both diseases. Step 1: doctor-patient discussion with explanation of diagnosis and prognosis as well as clarification of therapy goals; lifestyle adaptations; use of phytotherapeutics; step 2: symptom-oriented medication: for FD, PPIs or prokinetics; for IBS, antispasmodics, secretagogues, laxatives, bile acid sequestrants, antidiarrheals, antibiotics, probiotics; step 3: visceral analgesics (antidepressants).

Targeting the altered duodenal microenvironment in functional dyspepsia

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

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.

Meta-Analysis of the Association Between 5-Hydroxytryptamine Transporter Gene-Linked Polymorphic Region and Functional Dyspepsia and its Subtypes

Background: Association studies of variations in the 5-hydroxytryptamine (5-HT, serotonin) transporter gene-linked polymorphic region (5-HTTLPR) and functional dyspepsia (FD) have yielded contradictory results. Hence, we performed a meta-analysis to clarify inconsistencies between the 5-HTTLPR polymorphism with FD and it subtypes. Methods: We performed a literature search in PubMed, Embase, Web of Science, Cochrane Library, and CNKI, including articles published until March 2022. We calculated and pooled odds ratios (ORs) with their 95% confidence intervals (CIs) in Stata 15.0. Data extraction was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Cochrane Handbook for Systematic Reviews of Interventions. Results: The meta-analysis included six studies, comprising 488 cases and 1513 healthy controls. We did not observe a significant association between the 5-HTTLPR polymorphism and FD in the overall population. In subgroup analyses, the 5-HTTLPR polymorphism was significantly associated with FD-subtype epigastric pain syndrome (EPS) (SS vs. LL+LS, OR = 0.620, 95% CI: 0.414-0.930; SS vs. LS, OR = 0.640, 95% CI: 0.417-0.980; S vs. L, OR = 0.655, 95% CI: 0.471-0.911). However, no association was observed with the other subtype, postprandial distress syndrome (PDS). Conclusion: While the 5-HTTLPR polymorphism had no relationship with FD overall, splitting the disease into its subtypes revealed a clear association with EPS.

Usefulness of Bifidobacterium longum BB536 in Elderly Individuals With Chronic Constipation: A Randomized Controlled Trial

INTRODUCTION

Few reports exist regarding the therapeutic effects of probiotics on chronic constipation in elderly individuals. This study evaluated the effects of Bifidobacterium longum BB536 in elderly individuals with chronic constipation.

METHODS

This was a randomized, double-blind placebo-controlled, parallel-group superiority trial in Japan (UMIN 000033031). Eighty older adults diagnosed with chronic constipation were randomly assigned (1:1) to receive either probiotics ( B. longum BB536, 5 × 10 10 colony-forming unit, n = 39) or placebo (n = 41) once daily for up to 4 weeks. The severity of constipation was evaluated using the Constipation Scoring System. The primary end point was the difference in the changes from baseline in the constipation scoring system total score between the 2 groups at week 4.

RESULTS

A total of 79 patients (mean age of 77.9 years), including 38 patients in the BB536 group and 41 in the placebo group, completed the study. The primary end point was not significant ( P = 0.074), although there was significant improvement ( P < 0.01) in the BB536 group from baseline to week 4, but there were no significant changes in the placebo group. There was a significant difference and a tendency toward a difference in the changes from baseline on the stool frequency ( P = 0.008) and failure of evacuation ( P = 0.051) subscales, respectively, at week 4 between the 2 groups. Few adverse events related to the probiotics were observed.

DISCUSSION

The primary end points were not significant. However, probiotic supplementation significantly improved bowel movements. These results suggest that B. longum BB536 supplementation is safe and partially effective for improving chronic constipation in elderly individuals.

Low-grade duodenal eosinophilia is associated with cagA in Helicobacter pylori-related dyspepsia

BACKGROUND AND AIM

Functional dyspepsia (FD) is a multifactorial disorder. Helicobacter pylori (H. pylori)-related dyspepsia (HpD) may be considered a separate entity. Duodenal eosinophilia is a potential pathogenic mechanism in FD. However, the impact of duodenal eosinophilia and H. pylori virulence genes in HpD was not explored. We aim to evaluate the association of H. pylori virulence genes and low-grade duodenal eosinophilia in HpD.

METHODS

A multi-center cross-sectional study was conducted. A total of 301 patients who meet Rome-III criteria were selected before upper endoscopy, and 95 patients were included after normal endoscopy and positive H. pylori in gastric biopsies were assessed. Clinical parameters, H. pylori virulence genes (cagA, oipA, and vacA) and duodenal histology were evaluated.

RESULTS

Sixty-nine (72%) patients had epigastric pain syndrome (EPS), 17 (18%) post-prandial distress syndrome (PDS) and 9 (10%) EPS/PDS overlap. FD syndromes were not associated with cagA or oipA strains. A significantly trend of vacA s1/m1 (78%) and s1/m2 (80%) positive strains in EPS was observed. Histological duodenal grading of chronic inflammation, low-grade duodenal eosinophilia and intra-epithelial lymphocytes showed no difference in oipA and vacA strains. Low-grade duodenal eosinophilia was significant in cagA positive strain, and the OR for low-grade duodenal eosinophilia with H. pylori cagA positive strain was 4.2 (95% CI, 1.78-9.93). Adjusting for age, gender, smoking, diabetes, alcohol, PPI, and NSAID, the OR was 5.44 (1.989-14.902).

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is significantly associated with cagA strain in HpD.

Mechanisms underlying food-related symptoms in disorders of gut-brain interaction: Course ahead in research and clinical practice

A subgroup of patients with a disorder of gut-brain interaction (DGBI) report symptoms such as abdominal pain, gas-related symptoms, dyspeptic symptoms and loose stool or urgency after meal intake. Therefore, the effect of several dietary therapies including fibre-rich or restrictive diets have already been studied in patients with irritable bowel syndrome, functional abdominal bloating or distention, and functional dyspepsia. However, there is a paucity of studies in the literature on the mechanisms underlying food-related symptoms. Therefore, this review focuses on these potential mechanisms and explains the role of nutrient sensing and tasting, physical considerations, malabsorption or allergy-like reaction to food and its interaction with microbiota. In addition, it emphasizes the importance of future research and clinical practice regarding food-related symptoms in patients with a DGBI.

Probiotics in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder in everyday clinical practice identified nowadays as a multi-factorial, difficult to treat condition with a significant burden on patients' quality of life (QoL) and healthcare systems worldwide. Despite its high prevalence in the general population, the precise etiology of the disorder remains elusive, with its pathophysiological spectrum evolving over time, including variable potential mechanisms, i.e., impaired gastric accommodation, gastric motor disorders, hypersensitivity to gastric distention, disorders of the brain-gut axis, as well as less evident ones, i.e., altered duodenal microbiota composition and genetic susceptibility. In light of these implications, a definitive, universal treatment that could be beneficial for all FD patients is not available yet. Recently, probiotics have been suggested to be an effective therapeutic option that could alleviate gastrointestinal symptoms in patients with Irritable Bowel Syndrome (IBS), potentially due to anti-inflammatory properties or by modulating the complex bidirectional interactions between gastrointestinal microbiota and host crosstalk; however, their impact on the multiple aspects of FD remains ambiguous. In this review, we aim to summarize all currently available evidence for the efficacy of probiotics as a novel therapeutic approach for FD.

Research progress of treatment of functional dyspepsia with traditional Chinese medicine compound based on cell signal pathway

Functional dyspepsia (FD) is the most common clinical gastrointestinal disease, with complex and prolonged clinical symptoms. The prevalence of FD is increasing year by year, seriously affecting the quality of life of patients. The main causes of FD are related to abnormal gastrointestinal dynamics, increased visceral sensitivity, Helicobacter pylori (HP) infection, intestinal flora disturbance and psychological factors. A review of the relevant literature reveals that the mechanisms of traditional Chinese medicine (TCM) in the treatment of FD mainly involve the following pathways:5-HT signal pathway, AMPK signal pathway,C-kit signal pathway, CRF signal pathway, PERK signal pathway,NF-κB signal pathway. Based on a holistic concept, TCM promotes gastrointestinal motility, regulates visceral sensitivity and alleviates gastrointestinal inflammation through multiple signal pathways, reflecting the advantages of multi-level, multi-pathway and multi-targeted treatment of FD.

Type 2 and type 17 effector cells are increased in the duodenal mucosa but not peripheral blood of patients with functional dyspepsia

Background

Functional dyspepsia is characterised by chronic symptoms of post-prandial distress or epigastric pain not associated with defined structural pathology. Increased peripheral gut-homing T cells have been previously identified in patients. To date, it is unknown if these T cells were antigen-experienced, or if a specific phenotype was associated with FD.

Objective

This study aimed to characterise T cell populations in the blood and duodenal mucosa of FD patients that may be implicated in disease pathophysiology.

Methods

We identified duodenal T cell populations from 23 controls and 49 Rome III FD patients by flow cytometry using a surface marker antibody panel. We also analysed T cell populations in peripheral blood from 37 controls and 61 patients. Where available, we examined the number of duodenal eosinophils in patients and controls.

Results

There was a shift in the duodenal T helper cell balance in FD patients compared to controls. For example, patients had increased duodenal mucosal Th2 populations in the effector (13.03 ± 16.11, 19.84 ± 15.51, p=0.038), central memory (23.75 ± 18.97, 37.52 ± 17.51, p=0.007) and effector memory (9.80±10.50 vs 20.53±14.15, p=0.001) populations. Th17 populations were also increased in the effector (31.74±24.73 vs 45.57±23.75, p=0.03) and effector memory (11.95±8.42 vs 18.44±15.63, p=0.027) subsets. Peripheral T cell populations were unchanged between FD and control.

Conclusion

Our findings identify an association between lymphocyte populations and FD, specifically a Th2 and Th17 signature in the duodenal mucosa. The presence of effector and memory cells suggest that the microinflammation in FD is antigen driven.

Overexpression of microRNA-211 in Functional Dyspepsia via Downregulation of the Glial Cell Line-Derived Neurotrophic Factor (GDNF) by Increasing Phosphorylation of p38 MAPK Pathway

BACKGROUND

Overexpression of miRNA-211 suppresses the differentiation of bone marrow stem cells into intestinal ganglion cells via downregulation of GDNF, a regulator of intestine barrier function. The study aimed to investigate the interaction between miR-211 and GDNF on intestinal epithelial cells.

METHODS

The expression levels of miR-211 and GDNF in duodenal biopsy specimens from FD patients and healthy controls were compared. Enteric glia cell (EGCs) cell line transfected with miR-211 mimics and inhibitors were used to clarify the expression levels of GDNF were analyzed by qRT-PCR and ELISA. Intestine epithelial cell (IECs) cell line cultured in medium from ECGs in different transfection conditions were used in wound healing assay, cell proliferation assay, and western blotting for evaluation of p38 MAPK phosphorylation level.

RESULTS

MiR-211 expression was significantly upregulated in the duodenal tissue of patients with FD compared to healthy subjects, whereas GDNF expression was significantly downregulated (both p < 0.05). Transfection with miR-211 mimics significantly decreased GDNF mRNA expression and protein secretion (p < 0.001). An inhibited intestinal epithelial cell wound healing (p < 0.05) and increased expression levels of phosphorylated p38 MAPK (p < 0.05) were found in IECs cultured with medium from EGCs transfected with miR-211 mimics.

CONCLUSIONS

MiR-211 may downregulates GDNF mRNA and protein expression via activation of the pp38 MAPK signaling pathway. Targeting miR-211 or the MAPK pathway may be a potential intervention for FD.

Lactobacillus rhamnosus GG supplementation on eradication rate and dyspepsia in Helicobacter pylori infection treated with three-in-one bismuth quadruple therapy

Introduction

Helicobacter pylori (Hp)-related dyspepsia has been related to gastroduodenal dysbiosis. The role of probiotic supplementation in the clinical management of Hp infection has been the object of several studies in terms of improvement of efficacy and tolerability of eradication treatments but data on their effects on the outcomes of post-eradication dyspepsia are lacking. The aim of the present study was to evaluate the influence of Lactobacillus rhamnosus GG (LGG) supplementation on bismuth quadruple therapy (BQT) in the clinical management of Hp-related infection both in terms of efficacy and tolerability and persistence of post-treatment dyspepsia.

Methods

A total of 164 (121 women) Hp-positive adult patients were enrolled in this pilot study and assigned to two different treatment regimens: group A received BQT for 10 days (three capsules qid, IPP bid) and group B received BQT for 10 days in combination with 6 × 10⁹CFU LGG (ATCC53103) taken for 24 days (7 days before, 10 days during, and 7 days after therapy). Eradication was assessed after 45 days using the ¹³C-urea breath test (¹³C-UBT). Dyspepsia, distinguished into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), was assessed at the time of enrollment and 6 months after eradication.

Results

Approximately 98 patients were enrolled in group A and 66 patients in group B. At the enrollment, dyspepsia was present in 76.5% of group A and 86.5% of group B. No significant differences were observed in eradication rate between the 2 groups, both in intention-to-treat (ITT) analysis (82.3 vs. 75.0%) and per-protocol (PP) analysis (95 vs. 96%), and in the presence of side effects during the treatment (70.6 vs. 65.4%). At 6 months after eradication of Hp infection, the persistence of dyspepsia was statistically higher in patients of group A than in group B (38.8 vs. 16.1%; p = 0.032). The positive influence of LGG supplementation in improving post-eradication dyspepsia resulted in statistically more effectiveness in PDS dyspepsia, whose remission was 41.7% in group A and 84% in group B patients (p = 0.011).

Conclusion

In conclusion, LGG supplementation during Hp eradication therapy, even if not affecting eradication rates and therapy-related side effects, significantly impacts the remission of dyspepsia.

The Impact of Duodenal Mucosal Vulnerability in the Development of Epigastric Pain Syndrome in Functional Dyspepsia

An unidentified cause of functional dyspepsia (FD) is closely associated with medication resistance. Acid suppression is a traditional and preferential method for the treatment of FD, but the efficacy of this treatment varies between epigastric pain syndrome (EPS) and postprandial syndrome (PDS): it is efficient in the former but not much in the latter. Transepithelial electrical resistance (TEER), a surrogate of mucosal barrier function, was measured under pH 3 and pH 5 acidic conditions using duodenal biopsy specimens obtained from the patients with EPS and PDS and asymptomatic healthy controls. The infiltration of inflammatory cells to the duodenal mucosa was accessed by immunohistochemical analysis. The duodenal mucosal TEER in EPS patients was decreased by exposure to the acidic solution compared to that of the controls and the PDS patients. The decrease in TEER of the EPS patients was observed even under pH 5 weak acidic condition and was correlated to degree of the epigastric pain. Moreover, the duodenal mucosa of EPS patients presented an increase in mast cells and plasma cells that expressed Ig-E. Duodenal mucosal vulnerability to acid is likely to develop EPS.

Recognizing the role of the vagus nerve in depression from microbiota-gut brain axis

Depression is a worldwide disease causing severe disability, morbidity, and mortality. Despite abundant studies, the precise mechanisms underlying the pathophysiology of depression remain elusive. Recently, cumulate research suggests that a disturbance of microbiota-gut-brain axis may play a vital role in the etiology of depression while correcting this disturbance could alleviate depression symptoms. The vagus nerve, linking brain and gut through its afferent and efferent branches, is a critical route in the bidirectional communication of this axis. Directly or indirectly, the vagus afferent fibers can sense and relay gut microbiota signals to the brain and induce brain disorders including depression. Also, brain changes in response to stress may result in gut hyperpermeability and inflammation mediating by the vagal efferents, which may be detrimental to depression. Notably, vagus nerve stimulation owns an anti-inflammatory effect and was proved for depression treatment. Nevertheless, depression was accompanied by a low vagal tone, which may derive from response to stress and contribute to pathogenesis of depression. In this review, we aim to explore the role of the vagus nerve in depression from the perspective of the microbiota-gut-brain axis, highlighting the relationship among the vagal tone, the gut hyperpermeability, inflammation, and depression.