Anxiety and depression in irritable bowel syndrome: Exploring the interaction with other symptoms and pathophysiology using multivariate analyses

Decoding IBS: a machine learning approach to psychological distress and gut-brain interaction

PURPOSE

Irritable bowel syndrome (IBS) is a diagnosis defined by gastrointestinal (GI) symptoms like abdominal pain and changes associated with defecation. The condition is classified as a disorder of the gut-brain interaction (DGBI), and patients with IBS commonly experience psychological distress. The present study focuses on this distress, defined from reports of fatigue, anxiety, depression, sleep disturbances, and performance on cognitive tests. The aim was to investigate the joint contribution of these features of psychological distress in predicting IBS versus healthy controls (HCs) and to disentangle clinically meaningful subgroups of IBS patients.

METHODS

IBS patients ( n = 49 ) and HCs ( n = 28 ) completed the Chalder Fatigue Scale (CFQ), the Hamilton Anxiety and Depression Scale (HADS), and the Bergen Insomnia Scale (BIS), and performed tests of memory function and attention from the Repeatable Battery Assessing Neuropsychological Symptoms (RBANS). An initial exploratory data analysis was followed by supervised (Random Forest) and unsupervised (K-means) classification procedures.

RESULTS

The explorative data analysis showed that the group of IBS patients obtained significantly more severe scores than HCs on all included measures, with the strongest pairwise correlation between fatigue and a quality measure of sleep disturbances. The supervised classification model correctly predicted belongings to the IBS group in 80% of the cases in a test set of unseen data. Two methods for calculating feature importance in the test set gave mental and physical fatigue and anxiety the strongest weights. An unsupervised procedure with K = 3 showed that one cluster contained 24% of the patients and all but two HCs. In the two other clusters, their IBS members were overall more impaired, with the following differences. One of the two clusters showed more severe cognitive problems and anxiety symptoms than the other, which experienced more severe problems related to the quality of sleep and fatigue. The three clusters were not different on a severity measure of IBS and age.

CONCLUSION

The results showed that psychological distress is an integral component of IBS symptomatology. The study should inspire future longitudinal studies to further dissect clinical patterns of IBS to improve the assessment and personalized treatment for this and other patient groups defined as disorders of the gut-brain interaction. The project is registered at https://classic.

CLINICALTRIALS

gov/ct2/show/NCT04296552 20/05/2019.

Anxiety-Related Factors Associated With Symptom Severity in Irritable Bowel Syndrome in Jazan, Saudi Arabia

BACKGROUND

 This study in Jazan, Saudi Arabia aims to identify anxiety-related factors associated with symptom severity in irritable bowel syndrome (IBS). IBS is a common gastrointestinal disorder causing abdominal pain and altered bowel habits. The prevalence of IBS in Saudi Arabia is estimated to be 10%-20% among the general population. Therefore, the present study aimed to determine anxiety-related factors associated with symptom severity in irritable bowel syndrome in Jazan, Saudi Arabia. Understanding these factors will provide insights into the overall impact of IBS on patients' quality of life.

METHODS

The study utilized a cross-sectional, descriptive observational design to examine the general population in Jazan, Saudi Arabia. The sample size of 385 individuals was calculated based on the population size and desired error margin. A convenience sampling technique was employed to select participants who met the inclusion criteria. A validated anonymous self-administered electronic survey was distributed through social media channels. The survey consisted of four sections gathering demographic information, personal risk factors, IBS types with anxiety and risk factors, and a questionnaire to determine the level of anxiety. A pilot study was conducted to improve the survey's clarity. Ethical considerations were followed, and data were analyzed using Statistical Package for Social Sciences (SPSS; IBM Corp., Armonk, NY, USA). Descriptive statistics and significance tests were performed.

RESULT

A study with 637 participants found a 31.08% prevalence of IBS, which was more common in females. Participants with IBS had a higher rate of chronic disease. There were no significant differences in demographic factors between IBS and non-IBS participants. The duration of IBS diagnosis varied, with the majority of IBS with diarrhea (IBS-D) sufferers being diagnosed five years prior. Symptom severity differed among IBS types, with those with an unspecified type reporting the highest percentage of severe symptoms. IBS types were also correlated with anxiety levels, with IBS-D sufferers reporting moderate anxiety and those with an unspecified type reporting severe anxiety.

CONCLUSION

A study with 637 participants found the prevalence of IBS to be 31.08%, with higher rates in females. IBS was associated with chronic diseases and higher anxiety levels. The findings emphasize the need for comprehensive management of IBS, including psychological interventions and dietary modifications, to improve patients' overall health and quality of life. Further research on genetic and modifiable risk factors is needed.

Evolutionary medicine approaches to chronic disease: The case of irritable bowel syndrome

Irritable bowel syndrome (IBS), a gastrointestinal disease, is a global phenomenon correlated with industrialization. We propose that an evolutionary medicine approach is useful to understand this disease from an ultimate perspective and conducted a scoping literature review to synthesize the IBS literature within this framework. Our review suggests five potential evolutionary hypotheses for the cause of IBS, including (a) a dietary mismatch accompanying a nutritional transition, (b) an early hygienic life environment leading to the immune system and microbiotic changes, (c) an outcome of decreased physical activity, (d) a response to changes in environmental light-dark cycles, and (e) an artifact of an evolved fight or flight response. We find key limitations in the available data needed to understand early life, nutritional, and socioeconomic experiences that would allow us to understand evolutionarily relevant risk factors and identify a need for further empirical research to distinguish potential causes and test evolutionary hypotheses.

Relationship Between Colonic Transit Response to Eating With Self-reported Constipation Severity in Constipated Patients According to the Phenotype

Background/Aims

Eating is the major synchronizer of gastrointestinal motility and secretions. The present study aims to evaluate the interplay between self-perceived constipation severity (CS) and colonic response to eating in constipated patients according to the phenotype.

Methods

We included 387 consecutive outpatients complaining of Rome IV chronic idiopathic constipation. Likert scales for CS, abdominal pain severity, bloating severity, depression and anxiety assessment, total and segmental colonic transit time (CTT), and colonic transit response to eating (CTRE) were performed in all patients.

Results

Of the 387 patients included (49.7 ± 16.4 years), 320 (83%) were female, 203 had irritable bowel syndrome with constipation (IBS-C), 184 as functional constipation (FC), and 283 had defecation disorders (DD). The female gender was characterized by increased bloating severity (P = 0.011) and decreased Bristol stool form (P = 0.002). In IBS-C and FC patients, CS was related with bloating severity (P < 0.001 in both groups) and total CTT (P = 0.007 in IBS-constipation, P = 0.040 in FC). In IBS-C patients, CS was also associated with abdominal pain severity (P = 0.003) and Bristol stool form (P = 0.004). In contrast, in FC, CS was only related to left CTRE (P = 0.006), and in patients with DD, CS was associated with total CTT (P < 0.001) and left CTRE (P = 0.002).

Conclusion

Colonic transit response to eating was not associated to CS in IBS-C patients, but left CTRE was associated with constipation severity in FC and DD patients.

The gut microbiome in disorders of gut-brain interaction

Functional gastrointestinal disorders (FGIDs), chronic disorders characterized by either abdominal pain, altered intestinal motility, or their combination, have a worldwide prevalence of more than 40% and impose a high socioeconomic burden with a significant decline in quality of life. Recently, FGIDs have been reclassified as disorders of gut-brain interaction (DGBI), reflecting the key role of the gut-brain bidirectional communication in these disorders and their impact on psychological comorbidities. Although, during the past decades, the field of DGBIs has advanced significantly, the molecular mechanisms underlying DGBIs pathogenesis and pathophysiology, and the role of the gut microbiome in these processes are not fully understood. This review aims to discuss the latest body of literature on the complex microbiota-gut-brain interactions and their implications in the pathogenesis of DGBIs. A better understanding of the existing communication pathways between the gut microbiome and the brain holds promise in developing effective therapeutic interventions for DGBIs.

Integrated bioinformatics and network pharmacology identifying the mechanisms and molecular targets of Guipi Decoction for treatment of comorbidity with depression and gastrointestinal disorders

BACKGROUND

Guipi decoction (GPD) not only improves gastrointestinal (GI) function, but also depressive mood. The bioinformatics study aimed to reveal potential crosstalk genes and related pathways between depression and GI disorders. A network pharmacology approach was used to explore the molecular mechanisms and potential targets of GPD for the simultaneous treatment of depression comorbid GI disorders.

METHODS

Differentially expressed genes (DEGs) of major depressive disorder (MDD) were identified based on GSE98793 and GSE19738, and GI disorders-related genes were screened from the GeneCards database. Overlapping genes between MDD and GI disorders were obtained to identify potential crosstalk genes. Protein-protein interaction (PPI) network was constructed to screen for hub genes, signature genes were identified by LASSO regression analysis, and single sample gene set enrichment analysis (ssGSEA) was performed to analyze immune cell infiltration. In addition, based on the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, we screened the active ingredients and targets of GPD and identified the intersection targets of GPD with MDD and GI disorder-related genes, respectively. A "component-target" network was constructed using Cytoscape, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed.

RESULTS

The MDD-corrected dataset contained 2619 DEGs, and a total of 109 crosstalk genes were obtained. 14 hub genes were screened, namely SOX2, CRP, ACE, LEP, SHH, CDH2, CD34, TNF, EGF, BDNF, FN1, IL10, PPARG, and KIT. These genes were identified by LASSO regression analysis for 3 signature genes, including TNF, EGF, and IL10. Gamma.delta.T.cell was significantly positively correlated with all three signature genes, while Central.memory.CD4.T.cell and Central.memory.CD8.T.cell were significantly negatively correlated with EGF and TNF. GPD contained 134 active ingredients and 248 targets, with 41 and 87 relevant targets for the treatment of depression and GI disorders, respectively. EGF, PPARG, IL10 and CRP overlap with the hub genes of the disease.

CONCLUSION

We found that GPD may regulate inflammatory and oxidative stress responses through EGF, PPARG, IL10 and CRP targets, and then be involved in the treatment of both depression and GI disorders.

Global Prevalence of Psychological Distress and Comorbidity With Disorders of Gut-Brain Interactions

INTRODUCTION

This study focused on defining the global prevalence of clinically relevant levels of psychological distress and somatic symptoms and the prevalence of coexistence between these symptoms and disorders of gut-brain interaction (DGBI). We also analyzed how clinically relevant psychological distress and somatic symptoms and coexistent DGBI are associated with health-related outcomes.

METHODS

We included a representative sample of 54,127 adult participants (49.1% women; mean age of 44.3 years) from 26 countries worldwide. Participants completed an Internet survey (the Rome Foundation Global Epidemiology Study) with validated self-report questionnaires.

RESULTS

Clinically relevant psychological distress and/or somatic symptom severity was reported by 37.5% of the sample. These participants had 4.45 times higher odds to have at least one DGBI than individuals without psychological distress and/or somatic symptoms. Compared with participants with psychological distress and/or somatic symptoms with vs without DGBI, participants with a DGBI reported increased healthcare and medication utilization (with OR from 1.6 to 2.8). Coexistent DGBI in participants with psychological distress and/or somatic symptoms was the variable most strongly associated with reduced mental (β = -0.77; confidence interval [-0.86 to -0.68]) and physical (β = -1.17; confidence interval [-1.24 to -1.10]) quality of life.

DISCUSSION

This global study shows that psychological distress, somatic symptoms, and DGBI are very common and frequently overlap. The coexistence between psychological distress/somatic symptoms and DGBI seems to be especially detrimental to quality of life and healthcare utilization. Individuals with psychological distress/somatic symptoms and DGBI coexistence seem to be a group vulnerable to psychosocial problems that should be studied further and would likely benefit from psychological/psychiatric interventions.

Update in diagnosis and management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by a lack of structural or biochemical abnormalities. The current diagnosis of IBS is based on the Rome IV criteria, and it is recommended to approach IBS patients using a multidimensional clinical profile (MDCP). The pathophysiology of IBS is multifactorial and involves motility disorders, genetic factors, immune responses, visceral hypersensitivity, brain-gut dysregulation, and altered intestinal microbiota. The management of IBS includes both nonpharmacologic and pharmacologic therapies. Nonpharmacologic therapy options include physical activity, low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet, as well as cognitive behavioral therapy. Pharmacologic therapy options include probiotics, antidepressants, antispasmodics, and new agents. In clinical practice, a multidisciplinary strategy, including nonpharmacologic or/and pharmacologic treatment for IBS, is emphasized. Therefore, clinicians should carefully consider the underlying pathophysiology before selecting an appropriate therapeutic option for the treatment of IBS. In other words, individualized treatment plans are necessary for managing IBS.

Burden of anxiety and depression among hospitalized patients with irritable bowel syndrome: a nationwide analysis

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder that affects patients both physically and mentally. Our study aimed to investigate the burden of psychiatric disorders in IBS patients.

METHODS

We conducted a retrospective analysis of the National inpatient sample (NIS) from 2016 to 2019. We recruited patients admitted with a diagnosis of IBS and determined the prevalence of anxiety, depression, and suicide attempt/ideation.

RESULTS

We found a total of 1,256,325 hospitalizations with a diagnosis of IBS. Among them, 478,515 (38.1%) had anxiety and 344,165 (27.4%) had depression. The prevalence of psychiatric disorders including anxiety (38.1% vs. 15.1%), depression (38.1% vs. 15.1%), bipolar disorder (5.22% vs. 2.38%), suicidal attempt/Ideation (3.22% vs. 2.38%), and eating disorder (0.32% vs. 0.08%) was significantly higher in IBS patient population when compared to general adult population (p < 0.001). Patients with IBS had greater odds of anxiety (AOR 2.88, 95% CI 2.85-2.91, P < 0.001), depression (AOR 2.16, 95% CI 2.14-2.19, P < 0.001) and suicidal attempt/ideation (AOR 1.94, 95% CI 1.88-2.00, P < 0.001) in comparison to general population. IBS subtypes including diarrhea-predominant, constipation-predominant and mixed type were independently associated with increased odds of anxiety, depression, and suicide attempt/ideation. Patients with IBS and a co-diagnosis of anxiety or depression had increased mean length of hospital stay by 0.48 (95% CI 0.43-0.52, P < 0.001) and 0.52 (95% CI 0.06-0.97, P < 0.03) days, respectively.

CONCLUSION

The presence of IBS is associated with an increased associated prevalence of psychiatric disorders such as anxiety, depression, and suicide attempt/ideation.

Causal association between psycho-psychological factors, such as stress, anxiety, depression, and irritable bowel syndrome: Mendelian randomization

BACKGROUND

Pathogenesis, diagnosis, and treatment of irritable bowel syndrome (IBS) have been reported to be challenging hotspots in clinical practice. Previous observational studies have found that stress, anxiety, depression, and other mental and psychological diseases are closely associated with IBS. This study aimed to further explore the causal relationships of these associations through Mendelian randomization (MR).

METHODS

The data needed for MR were obtained from publicly published genome-wide association databases. We performed a bidirectional, 2-sample MR analysis using instrumental variables (IV) associated with stress, anxiety, and depression, and other mental and psychological factors as exposures and IBS as the outcome. A reverse MR analysis with IBS as exposure and stress, anxiety, depression, and other mental and psychological factors as the outcomes was also performed. The inverse variance weighting (IVW) method was adopted as the main method of MR, and the causal effect between stress, anxiety, depression, and other mental and psychological factors and IBS was evaluated as the main result of the study. In addition, a series of sensitivity analyses was conducted to comprehensively evaluate the causal relationship between them.

RESULTS

Stress, anxiety, depression, and other mental and psychological factors were the underlying etiologies for IBS (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.03-1.08), and they were positively correlated. Univariate analysis further supported the above conclusions (Depression, [OR = 1.31, 95% CI: 1.05-1.63, P = .016], Anxiety, [OR = 1.53, 95% CI: 1.16-2.03, P = .003]). However, in reverse MR analysis, we found that IBS did not affect stress, anxiety, depression, or other mental and psychological factors and that there was no causal relationship between IBS and stress, anxiety, depression, or other mental and psychological factors (P > .05).

CONCLUSION

This study demonstrates that mental and psychological factors are the underlying etiologies for IBS. These findings may provide important information for physicians regarding the clinical treatment of IBS.

Clinical outcome of disorders of gut-brain interaction in secondary care: A longitudinal study

BACKGROUND

Real-world data on the outcome of routine treatment for disorders of gut-brain interaction (DGBI) in secondary care are lacking.

METHOD

A longitudinal study of consecutive adult patients with various DGBI attending this institution's gastroenterology clinic was conducted. Following 2 years of treatment, the proportion of patients with symptom improvement, details of clinical therapy, factors associated with and the impact of 'no symptom improvement' were determined.

RESULTS

A total of 289 patients (median age 68 years; 64.7% females; 28.4% irritable bowel syndrome (IBS), 20.1% functional dyspepsia (FD), 8.7% functional constipation (FC), 42.9% overlap syndrome) were recruited. After 2 years, 66.1% patients reported symptom improvement. Patients with overlap syndrome were less likely to have symptomatic improvement compared to those with a single DGBI (Overlap 55.6% vs IBS 74.4% vs FD 72.4% vs FC 76.0%, p = 0.014). Reassurance was associated with symptom improvement (p < 0.001). On multivariate analysis, overlap syndrome remained significantly associated with a poorer outcome (OR 2.27, 95% CI 1.22-4.25, p = 0.010), while providing reassurance was associated with a positive outcome (OR 0.30, 95% CI 0.16-0.56, p < 0.001). Only 25.6% and 14.9% of patients were referred for a low FODMAP diet and psychiatric intervention respectively. DGBI patients who had 'no improvement' were more likely to seek further GI consultations and had more work absenteeism.

CONCLUSION

Two-thirds of DGBI patients in secondary care showed symptom improvement. Patients who were reassured had better symptom improvement, while those with an overlap syndrome were associated with a poorer outcome, resulting in greater healthcare consultation and work absenteeism.

Assessment of Self-Reported Executive Function in Patients with Irritable Bowel Syndrome Using a Machine-Learning Framework

Introduction: Irritable bowel syndrome (IBS) is characterized as a disorder of the gut-brain interaction (DGBI). Here, we explored the presence of problems related to executive function (EF) in patients with IBS and tested the relative importance of cognitive features involved in EF. Methods: A total of 44 patients with IBS and 22 healthy controls (HCs) completed the Behavior Rating Inventory of Executive Function (BRIEF-A), used to identify nine EF features. The PyCaret 3.0 machine-learning library in Python was used to explore the data, generate a robust model to classify patients with IBS versus HCs and identify the relative importance of the EF features in this model. The robustness of the model was evaluated by training the model on a subset of data and testing it on the unseen, hold-out dataset. Results: The explorative analysis showed that patients with IBS reported significantly more severe EF problems than the HC group on measures of working memory function, initiation, cognitive flexibility and emotional control. Impairment at a level in need of clinical attention was found in up to 40% on some of these scales. When the nine EF features were used as input to a collection of different binary classifiers, the Extreme Gradient Boosting algorithm (XGBoost) showed superior performance. The working memory subscale was consistently selected with the strongest importance in this model, followed by planning and emotional control. The goodness of the machine-learning model was confirmed in an unseen dataset by correctly classifying 85% of the IBS patients. Conclusions: The results showed the presence of EF-related problems in patients with IBS, with a substantial impact of problems related to working memory function. These results suggest that EF should be part of an assessment procedure when a patient presents other symptoms of IBS and that working memory function should be considered a target when treating patients with the disorder. Further studies should include measures of EF as part of the symptom cluster characterizing patients with IBS and other DGBIs.

Probiotics for the treatment of depression and its comorbidities: A systemic review

Depression is one of the most common psychiatric conditions, characterized by significant and persistent depressed mood and diminished interest, and often coexists with various comorbidities. The underlying mechanism of depression remain elusive, evidenced by the lack of an appreciate therapy. Recent abundant clinical trials and animal studies support the new notion that the gut microbiota has emerged as a novel actor in the pathophysiology of depression, which partakes in bidirectional communication between the gut and the brain through the neuroendocrine, nervous, and immune signaling pathways, collectively known as the microbiota-gut-brain (MGB) axis. Alterations in the gut microbiota can trigger the changes in neurotransmitters, neuroinflammation, and behaviors. With the transition of human microbiome research from studying associations to investigating mechanistic causality, the MGB axis has emerged as a novel therapeutic target in depression and its comorbidities. These novel insights have fueled idea that targeting on the gut microbiota may open new windows for efficient treatment of depression and its comorbidities. Probiotics, live beneficial microorganisms, can be used to modulate gut dysbiosis into a new eubiosis and modify the occurrence and development of depression and its comorbidities. In present review, we summarize recent findings regarding the MGB axis in depression and discuss the potential therapeutic effects of probiotics on depression and its comorbidities.

The relationship between fermentable carbohydrates and post-prandial bowel symptoms in patients with functional bowel disorders

Background and aims

A low fermentable oligosaccharide, disaccharide, monosaccharide, and polyols (FODMAP) diet alleviates symptoms of irritable bowel syndrome (IBS). We aimed to investigate the relationship between habitual FODMAP intake and post-prandial bowel symptoms in adults with IBS, functional diarrhoea (FD), or constipation (FD) (functional bowel disorders), and in healthy adults (controls).

Methods

292 participants (173 with functional bowel disorders and 119 controls) completed a food and symptom times diary. Estimated meal portion sizes were entered into the Monash FODMAP Calculator to analyse FODMAP content. Wilcoxon and ANOVA tests were used to investigate the relationship between FODMAP intake and post-prandial bowel symptoms.

Results

IBS participants experienced more post-prandial bowel symptoms compared to participants with other functional bowel disorders or controls. Meals associated with abdominal pain contained on average increased excess fructose (0.31 g vs. 0.18 g, p < 0.05), sorbitol (0.27 g vs. 0.10 g, p < 0.01), and total FODMAP (3.46 g vs. 2.96 g, p < 0.05) compared to meals not associated with pain. Abdominal swelling was associated with increased sorbitol (0.33 g vs. 0.11 g, p < 0.01), and total FODMAP (3.26 g vs. 3.02 g, p < 0.05) consumption. Abdominal bloating was associated with increased galacto oligosaccharide consumption (0.18 g vs. 0.14 g, p < 0.05).

Conclusion

These findings support the role of FODMAP in post-prandial bowel symptom onset, however, the amount and type of FODMAP triggering symptoms vary between individuals. Future research should investigate the relationship between the effect of individual FODMAP consumption on post-prandial bowel symptoms for each subtype, the interaction of FODMAP with differing functional bowel disorders and whether longitudinally symptoms and dietary intake are stable.

Symptom management needs of patients with irritable bowel syndrome and concurrent anxiety and/or depression: A qualitative study

AIMS

To understand the experiences and needs of symptom management among individuals with irritable bowel syndrome and concurrent symptoms of anxiety and/or depression.

DESIGN

This study used a qualitative descriptive research design.

METHODS

Individuals with a diagnosis of irritable bowel syndrome and concurrent symptoms of anxiety and/or depression participated were recruited through an online ResearchMatch and a listserv. Semi-structured interviews focused on symptoms and experiences with symptom management interventions conducted from June to August 2020. Interviews were transcribed and data were analysed based on thematic analysis.

RESULTS

Twelve individuals participated in this study; all reported current irritable bowel syndrome and anxiety/depression symptoms. The data analysis cumulated with three themes related to symptom management: (a) irritable bowel syndrome negatively impacts physical and mental well-being; (b) a trial and error approach to symptom management; and (c) challenges with healthcare professionals supporting symptom management including negative interactions with healthcare professionals and lack of nutritional expertize and support.

CONCLUSION

There is a need for individualized approaches which consider patients' current symptoms of anxiety and depression, previous experiences with the trial-and-error process and consideration for intervention delivery methods.

IMPACT

There is a limited qualitative research focusing on the experiences of individuals with irritable bowel syndrome and concurrent symptoms of anxiety and/or depression. This research highlights the need for individualized approaches to enhance symptom management that acknowledges patients' psychological state and past negative experiences with providers and prior dietary regimens.

A psychological symptom based machine learning model for clinical evaluation of irritable bowel syndrome

Background: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by recurrent abdominal pain associated with alterations  in stool form and/or stool frequency. Co-morbidities such as anxiety, depression, fatigue, and insomnia are frequently reported by patients suffering from IBS. Identification of these symptoms should thus be an integral part of an IBS assessment.      However, an optimal tool to screen for core psychological symptoms in IBS is still  missing. Here, we aim to develop a psychological symptom based machine learning model to efficiently help clinicians to identify patients suffering from IBS. Methods: We developed a machine learning workflow to select the most significant psychological features associated with IBS in a dataset including 49 patients with IBS and 35 healthy controls. These features were used to train three different types of machine learning models: logistic regression, decision trees and support vector machine classifiers; which were validated on a holdout validation dataset and an unseen test set. The performance of these models was compared in terms of balanced accuracy scores. Results: A logistic regression model including a combination of symptom features associated with anxiety and fatigue resulted in a balanced accuracy score of 0.93 (0.81-1.0) on unseen test data and outperformed the other comparable models. The same model correctly identified all patients with IBS in a test set (recall score 1) and misclassified one non-IBS subject (precision score 0.91). A complementary post-hoc leave-one-out cross validation analysis including the same symptom features showed similar, but slightly inferior results (balanced accuracy 0.84, recall 0.88, precision 0.86). Conclusions: Inclusion of machine learning based psychological evaluation can complement and improve existing clinical procedure for diagnosis of IBS.

Interactions between symptoms and psychological status in irritable bowel syndrome: An exploratory study of the impact of a probiotic combination

BACKGROUND

Stress is an exacerbator of irritable bowel syndrome (IBS) symptoms, and anxiety and depression are co-morbidities. Bifidobacterium longum strains 1714® and 35642® attenuate stress responses in healthy people and reduce symptoms in IBS, respectively. Here, we explore relationships between the psychological and visceral effects of the two strains (COMBO) in IBS subjects and biomarkers of stress and inflammation.

METHODS

We recruited 40 patients with IBS (Rome III) and mild to moderate anxiety (HADS-A) and/or depression (HADS-D) and 57 asymptomatic female controls with low or moderate stress. IBS patients were fed COMBO (1 × 10⁹ cfu/day) for 8 weeks with an 8-week washout. IBS symptoms, psychometric measures, salivary cortisol awakening response (CAR), and plasma inflammatory biomarkers were assessed every 4 weeks.

KEY RESULTS

Compared to healthy controls, IBS subjects had a blunted CAR. Treatment with COMBO restored CAR and improved IBS symptoms compared to baseline during the treatment phase. The COMBO reduced HADS-D, HADS-A score, and TNF-α, while sleep quality improved significantly from baseline to the end of the intervention. Surprisingly, these parameters improved further once treatment ended and maintained this improvement by Week 16.

CONCLUSIONS AND INFERENCES

These findings suggest that the stress response is a major driver of IBS symptoms. The time course of the beneficial effect of COMBO on IBS symptoms suggests that this is achieved through a restoration of the stress response. In contrast, the time course of the effects of COMBO on anxiety and depression in IBS paralleled an anti-inflammatory effect as indicated by a reduction in circulating levels of TNF-α.

Clinical significance and related factors of rectal hyposensitivity in patients with functional defecation disorder

Background

Rectal hyposensitivity (RH) is not uncommon in patients with functional defecation disorder (FDD). FDD patients with RH are usually unsatisfied with their treatment.

Aims

The aim of this study was to find the significance of RH in patients with FDD and the related factors of RH.

Methods

Patients with FDD first completed clinical questionnaires regarding constipation symptoms, mental state, and quality of life. Then anorectal physiologic tests (anorectal manometry and balloon expulsion test) were performed. Rectal sensory testing (assessing rectal response to balloon distension using anorectal manometry) was applied to obtain three sensory thresholds. Patients were separated into three groups (non-RH, borderline RH, and RH) based on the London Classification. The associations between RH and clinical symptoms, mental state, quality of life, and rectal/anal motility were investigated.

Results

Of 331 included patients with FDD, 87 patients (26.3%) had at least one abnormally elevated rectal sensory threshold and 50 patients (15.1%) were diagnosed with RH. Patients with RH were older and mostly men. Defecation symptoms were more severe (p = 0.013), and hard stool (p < 0.001) and manual maneuver (p = 0.003) were more frequently seen in the RH group. No difference in rectal/anal pressure was found among the three groups. Elevated defecatory desire volume (DDV) existed in all patients with RH. With the number of elevated sensory thresholds increasing, defecation symptoms got more severe (r = 0.35, p = 0.001). Gender (male) (6.78 [3.07-15.00], p < 0.001) and hard stool (5.92 [2.28-15.33], p < 0.001) were main related factors of RH.

Conclusion

Rectal hyposensitivity plays an important role in the occurrence of FDD and is associated with defecation symptom severity. Older male FDD patients with hard stool are prone to suffer from RH and need more care.

Dynorphin participates in interaction between depression and non-erosive reflux disease

BACKGROUND

To explore the relationships between anxiety/depression and NERD, we focused on dynorphin (Dyn), an important member of visceral hypersensitivity, and its related pathways.

METHODS

Pearson's correlation analysis on patients with NERD and in vivo experiment on NERD rat model. Part 1: Pearson's correlation analysis among serum levels of Dyn, clinical symptoms and HADS scores of NERD patients were carried on. Part 2: Wistar rats were randomly divided into 2 groups: control group and model group. The data of pH value, immobility time, serum Dyn concentration, NMDAR1 and SP expression were, respectively, derived from automatic pH recorder, tail suspension test, enzyme-linked immunosorbent assay, immunohistochemistry and immunofluorescence.

RESULTS

Part 1: Pearson's correlation analysis showed that there was a linear correlation between Clinical Symptom (CS) score and HADS score (HAD-A, HAD-D), and the correlation coefficients were 0.385 and 0.273 respectively; the correlation coefficient between lg (Dyn) and lg (CS score) was r = 0.441, P = 0.002; the correlation coefficient between lg(Dyn) and lg (HAD-D score) was r = 0.447, P = 0.002. Part 2: The pH value of the lower esophagus in the model group was lower than that in the control group (P < 0.01). The tail suspension immobility time of model group was significantly longer than that of control group (P < 0.01). The serum Dyn concentration and the expression level of NMDAR1 in spinal cord and SP in lower esophageal mucosa of model group were significantly higher than those of control group (P < 0.05).

CONCLUSION

Increased serum dynorphin level may be a sign of correlation between depression and NERD.

Global Research Trends in Irritable Bowel Syndrome: A Bibliometric and Visualized Study

Background

There are about 10–23% of adults worldwide suffering from irritable bowel syndrome (IBS). Over the past few decades, there are many aspects of uncertainty regarding IBS leading to an ongoing interest in the topic as reflected by a vast number of publications, whose heterogeneity and variable quality may challenge researchers to measure their scientific impact, to identify collaborative networks, and to grasp actively researched themes. Accordingly, with help from bibliometric approaches, our goal is to assess the structure, evolution, and trends of IBS research between 2007 and 2022.

Methods

The documents exclusively focusing on IBS from 2007 to 2022 were retrieved from the Science Citation Index Expanded of the Web of Science Core Collection. The annual productivity of IBS research, and the most prolific countries or regions, authors, journals and resource-, intellectual- and knowledge-sharing in IBS research, as well as co-citation analysis of references and keywords were analyzed through Microsoft Office Excel 2019, CiteSpace, and VOSviewer.

Results

In total, 4,092 publications were reviewed. The USA led the list of countries with the most publications (1,226, 29.96%). Mayo Clinic contributed more publications than any other institution (193, 4.71%). MAGNUS SIMREN stood out as the most active and impactful scholar with the highest number of publications and the greatest betweenness centrality value. The most high-yield journal in this field was Neurogastroenterology and motility: the official journal of the European Gastrointestinal Motility Society (275, 6.72%). Gastroenterology had the most co-citations (3,721, 3.60%). Keywords with the ongoing strong citation bursts were chromogranin A, rat model, peptide YY, gut microbiota, and low-FODMAP diet, etc.

Conclusion

Through bibliometric analysis, we gleaned deep insight into the current status of literature investigating IBS for the first time. These findings will be useful to scholars interested in understanding the key information in the field, as well as identifying possible research frontiers.

The Prevalence of Irritable Bowel Syndrome Among Chinese University Students: A Systematic Review and Meta-Analysis

Background

Irritable bowel syndrome (IBS) has become a common public health issue among university students, impairing their physical and mental health. This meta-analysis aimed to examine the pooled prevalence of IBS and its associated factors among Chinese university students.

Methods

Databases of PubMed, EMBASE, MEDLINE (via EBSCO), CINAHL (via EBSCO), Wan Fang, CNKI and Weipu (via VIP) were systematically searched from inception date to May 31, 2021. Meta-analysis was performed using random-effects models. Meta-regression and subgroup analysis were used to detect the potential source of heterogeneity.

Key Results

A total of 22 cross-sectional studies (14 were in Chinese and 8 were in English) with 33,166 Chinese university students were included. The pooled prevalence of IBS was estimated as 11.89% (95% CI = 8.06%, 16.35%). The prevalence was 10.50% (95% CI = 6.80%, 15.87%) in Rome II criteria, 12.00% (95% CI = 8.23%, 17.17%) in Rome III criteria, and 3.66% (95% CI = 2.01%, 6.60%) in Rome IV criteria. The highest prevalence of IBS was 17.66% (95% CI = 7.37%, 36.64%) in North China, and the lowest was 3.18% (95% CI = 1.28%, 7.68%) in South China. Subgroup analyses indicated that gender, major, anxiety and depression symptoms, drinking and smoking behaviors were significantly associated with the prevalence of IBS. Meta-regression analyses suggested that region influenced prevalence estimates for IBS.

Conclusions and Inferences

This meta-analysis illustrated that IBS is very common in Chinese university students. Regular screening, effective prevention, and appropriate treatments should be implemented to reduce the risk of IBS in this population. More future studies should be conducted in Northeastern and Southwestern parts of China.

Physical multimorbidity and psychological distress among Chinese older adults: Findings from Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Research has linked multimorbidity with psychological distress among people with multimorbidity but the available findings are inconsistent. This study was to investigate the prevalence of multimorbidity and incidence of psychological distress in a nationally representative sample of Chinese older adults and examine the association between multimorbidity and psychological distress in this population.

METHODS

This study was a cross-sectional, secondary analysis using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Participants' socio-demographic characteristics and clinical information were obtained. Psychological distress including anxiety and depression were assessed by the Generalized Anxiety Disorder-7 (GAD-7) and the Center for Epidemiologic Studies Depression Scale (10-item CES-D). Binary logistic regression was used to ascertain the association between multimorbidity and psychological distress with covariates adjustment.

RESULTS

Compared with those without physical chronic conditions, having five or more physical chronic conditions was associated with the likelihood of depression after covariates adjustment.

CONCLUSION

Psychological distress is a common health issue among Chinese older adults with multimorbidity. Having multimorbidity might not be associated with psychological distress represented by anxiety and depression. Management of multimorbidity among this population would benefit from more attention on the mental health domain.

Cross-lagged analyses between gastrointestinal symptoms, psychological distress, and disability in emerging adults

The gut-brain connection refers to communication between the brain and gastrointestinal (GI) system. Disorders of gut-brain interaction (DGBI) are characterized by GI symptoms that accompany distress and disability. Epidemiological research has suggested DGBI rates in emerging adults are increasing. This study investigated the relationship between GI health, distress, and disability in emerging adults across time. Emerging adults were recruited. A repeated-measure design with a 1-month time lag was used to collect data via an online survey (N = 861) across five academic semesters (Spring 2019 to Summer 2020). Measurement equivalence across time was established and a cross-lagged panel model (CLPM) was specified. Distress at Time 1 predicted GI symptoms at Time 2 (β = .206, SE = .084, p < .05). GI symptoms at Time 1 predicted disability at Time 2 (β = .117, SE = .039, p < .01). Higher disability at Time 1 predicted distress at Time 2 (β = .092, SE = .027, p < .01). The cross-lagged design offers stronger causal inferences than cross-sectional studies used to study the effects of GI symptoms. Findings provide initial evidence of a directional pathway between brain and gut rather than a bidirectional network. Findings highlight the importance of psychogastroenterology.

Associations of Habitual Dietary Intake With Fecal Short-Chain Fatty Acids and Bowel Functions in Irritable Bowel Syndrome

BACKGROUND GOALS

Diet may contribute to symptoms of irritable bowel syndrome (IBS) and luminal production of putative IBS biomarkers including short-chain fatty acids (SCFAs). Study aims were to to assess relationships of habitual fiber or starch intake with fecal SCFAs in patients with IBS and healthy volunteers (HVs).

STUDY

In 18 HVs and 30 patients with IBS (13 constipation-predominant [IBS-C] and 17 diarrhea-predominant [IBS-D]), habitual diet using a food frequency questionnaire; bowel functions using a validated bowel diary; and fecal SCFAs by HPLC-mass spectrometry were assessed. Associations of fiber and starch with SCFAs were analyzed using Spearman (rs) and Pearson (R) correlations. Relationships between other dietary endpoints, SCFAs, and bowel functions were explored.

RESULTS

Habitual fiber or starch intakes were not significantly correlated with SCFAs or bowel functions in all participants or HVs nor with SCFAs in IBS. Starch was negatively correlated (R=-0.53; P=0.04) with complete evacuation in IBS-D. Fiber (rs=0.65; P=0.02) and starch (rs=0.56; P=0.05) were correlated with ease of passage in IBS-C. Stool form, frequency, and ease of passage were positively correlated with total SCFAs (all P<0.05), acetate (all P<0.01), propionate (all P<0.05), and butyrate (form P=0.01; ease of passage P=0.05) among all participants, but not in IBS. Complete evacuation was negatively correlated with propionate (R=-0.34; P=0.04) in all participants. Total (P=0.04) and individual SCFAs (all P<0.05) were positively correlated with stool form in HVs.

CONCLUSIONS

Habitual fiber and starch intake does not influence fecal SCFAs but may influence bowel functions in IBS. Fecal SCFAs correlate with bowel functions among all participants including HVs.

Impact of COVID-19 on Individuals With Irritable Bowel Syndrome and Comorbid Anxiety and/or Depression

GOALS

The goal of this study was to describe the influence of the COVID-19 pandemic on ability to engage in activities and the influence on psychological distress and gastrointestinal symptoms among individuals with irritable bowel syndrome (IBS) and comorbid anxiety and/or depression.

BACKGROUND

Individuals with IBS and comorbid anxiety and/or depression report increased symptoms and decreased quality of life compared with individuals with IBS alone. The current COVID-19 pandemic has the potential to further influence symptoms among individuals with IBS and comorbid anxiety and/or depression.

STUDY

Individuals who met the Rome-IV IBS criteria and reported mild to severe anxiety and/or depression were included. Participants completed an online survey with questions about anxiety, depression, impact of COVID on activities and symptoms, and demographics.

RESULTS

Fifty-five individuals participated in the study. The COVID-19 pandemic most commonly influenced their ability to spend time with friends and family, shop for certain types of food, and access health care. Participants also reported increased stress (92%), anxiety (81%), and depressive symptoms (67%). Finally, around half the sample reported increases in abdominal pain (48%), diarrhea (45%), or constipation (44%).

CONCLUSIONS

The COVID-19 pandemic is related to self-reported increases in psychological distress and gastrointestinal symptoms among individuals with IBS and comorbid anxiety and/or depression. Additional research is needed to intervene on these symptoms.

The Associations of Single Nucleotide Polymorphisms with Risk and Symptoms of Irritable Bowel Syndrome

Although several risk single nucleotide polymorphisms (SNPs) have been found to play an important role in etiology of irritable bowel syndrome (IBS), the findings are inconsistent. A descriptive correlational design was used to analyze the baseline data of a randomized controlled trial including participants with IBS and healthy controls (HC). Pain severity and interference, anxiety, sleep, and fatigue were measured using the Brief Pain Inventory (BPI) and patient-reported outcomes measurement information system (PROMIS). Fisher’s exact test and multivariate linear regression were used to investigate the associations between IBS risk alleles and IBS symptoms. Participants were predominantly female, white, and had an average age of 21.13 ± 2.42 years. Polymorphisms within TNFSF15 (rs4263839), SLC6A4 5-HTTLPR, HTR3A (rs1062613), and OXTR (rs2254298) were associated with IBS risk, and TNFSF15 (rs4263839), COMT (rs6269), SLC6A4 5-HTTLPR polymorphisms were associated with pain severity. TNFSF15 (rs4263839) and COMT (rs4680; rs4633) genotypes were associated with sleep disturbance, and the ADRA1D SNP rs1556832 was associated with fatigue in both IBS and HC groups. Genotypic differences were associated with IBS risk and symptoms including abdominal pain, sleep disturbance, and fatigue. Further investigation is warranted to reveal the mechanisms by which these genetic variations influence the dynamic nature of IBS symptoms over time.

Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome

(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake, non-gastrointestinal (GI) somatic symptoms, GI-specific anxiety, and psychological distress. Outcomes were bloating, constipation, diarrhea, and pain symptom scores treated as continuous variables in linear mixed models. (3) Results: We included 33 and 34 patients on the low FODMAP and traditional IBS diet, respectively. Less severe dysbiosis and higher energy intake predicted better pain response to both diets. Less severe dysbiosis also predicted better constipation response to both diets. More severe psychological distress predicted worse bloating response to both diets. For the different outcomes, several differential predictors were identified, indicating that baseline factors could predict better improvement in one treatment arm, but worse improvement in the other treatment arm. (4) Conclusions: Psychological, nutritional, and microbial factors predict symptom improvement when following the low FODMAP and traditional IBS diet. Findings may help individualize dietary treatment in IBS.

AhR/IL-22 pathway as new target for the treatment of post-infectious irritable bowel syndrome symptoms

Alterations in brain/gut/microbiota axis are linked to Irritable Bowel Syndrome (IBS) physiopathology. Upon gastrointestinal infection, chronic abdominal pain and anxio-depressive comorbidities may persist despite pathogen clearance leading to Post-Infectious IBS (PI-IBS). This study assesses the influence of tryptophan metabolism, and particularly the microbiota-induced AhR expression, on intestinal homeostasis disturbance following gastroenteritis resolution, and evaluates the efficacy of IL-22 cytokine vectorization on PI-IBS symptoms. The Citrobacter rodentium infection model in C57BL6/J mice was used to mimic Enterobacteria gastroenteritis. Intestinal homeostasis was evaluated as low-grade inflammation, permeability, mucosa-associated microbiota composition, and colonic sensitivity. Cognitive performances and emotional state of animals were assessed using several tests. Tryptophan metabolism was analyzed by targeted metabolomics. AhR activity was evaluated using a luciferase reporter assay method. One Lactococcus lactis strain carrying an eukaryotic expression plasmid for murine IL-22 (L. lactisIL-22) was used to induce IL-22 production in mouse colonic mucosa. C. rodentium-infected mice exhibited persistent colonic hypersensitivity and cognitive impairments and anxiety-like behaviors after pathogen clearance. These post-infectious disorders were associated with low-grade inflammation, increased intestinal permeability, decrease of Lactobacillaceae abundance associated with the colonic layer, and increase of short-chain fatty acids (SCFAs). During post-infection period, the indole pathway and AhR activity were decreased due to a reduction of tryptophol production. Treatment with L. lactisIL-22 restored gut permeability and normalized colonic sensitivity, restored cognitive performances and decreased anxiety-like behaviors. Data from the video-tracking system suggested an upgrade of welfare for mice receiving the L.lactisIL-22 strain. Our findings revealed that AhR/IL-22 signaling pathway is altered in a preclinical PI-IBS model. IL-22 delivering alleviate PI-IBS symptoms as colonic hypersensitivity, cognitive impairments, and anxiety-like behaviors by acting on intestinal mucosa integrity. Thus, therapeutic strategies targeting this pathway could be developed to treat IBS patients suffering from chronic abdominal pain and associated well-being disorders.

Irritable bowel syndrome in women: Association between decreased insular subregion volumes and gastrointestinal symptoms

•

All insular subregions are smaller in IBS compared to healthy women.

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Insular volume associates with GI symptoms independent of psychiatric comorbidity.

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GI symptoms associate with anterior but not posterior insular volume.

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More nausea associated with smaller dorsal anterior insula bilaterally.

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Insula in major depression is not significantly smaller than in healthy women.

Objective

Irritable bowel syndrome (IBS) is a chronic pain disorder characterized by disturbed interactions between the gut and the brain with depression as a common comorbidity. In both IBS and depression, structural brain alterations of the insular cortices, key structures for pain processing and interoception, have been demonstrated but the specificity of these findings remains unclear. We compared the gray matter volume (GMV) of insular cortex (IC) subregions in IBS women and healthy controls (HC) and examined relations to gastrointestinal (GI) symptoms and glutamate + glutamine (Glx) concentrations. We further analyzed GMV of IC subregions in women with major depression (MDD) compared to HC and addressed possible differences between depression, IBS, IBS with depression and HC.

Design

Women with IBS (n = 75), MDD (n = 41) and their respective HC (n = 39 and n = 43) underwent structural brain MRI. IC subregion volumes were estimated using statistical parametric mapping software. General linear model approaches were applied to IC volumetric data and FDR-corrected partial correlation analyses assessed relations between GMV, GI symptoms and Glx concentrations.

Results

IBS patients had significantly smaller IC subregions than HC in both hemispheres but there was no significant difference between MDD compared with IBS and HC for any insular subregion. In IBS, the dorsal anterior insular volumes were negatively correlated with symptoms of nausea and pain, and the left ventral subregion showed a positive correlation with straining to defecate, while the posterior subregion volumes showed no relation to symptoms. In the anterior insula, concentration of Glx showed positive correlations with GMV bilaterally in HC and with GMV of the right anterior insula in IBS.

Conclusion

As the interoceptive cortex, the insula shows substantial and disease-specific structural differences in patients with chronic interoceptive visceral pain. Particularly changes in the anterior proportions might be related to chronic exposure to or enhanced salience towards adverse interoceptive visceral signals and could be linked to biochemical changes, calling for further multimodal and longitudinal work.

Influence of Irritable Bowel Syndrome on Stress and Depressive Symptoms in Nurses: The Korea Nurses' Health Study

Despite the high risk of irritable bowel syndrome (IBS) and stress/depressive symptoms in nurses, limited research has examined the relationship between these conditions in female nurses. The purpose of this study was to determine the prevalence of IBS and the influence of IBS on stress and depressive symptoms in female nurses. We analyzed the data from the Korea Nurses’ Health Study. Among 7667 participants from the 7th survey conducted from December 2018 to September 2019, 178 nurses were identified as having IBS based on the Rome IV criteria. Using the propensity score matching, 712 were selected as a comparison group. Multivariate ordinal logistic regression analyses were conducted to examine the influence of IBS on stress and depressive symptoms. The prevalence of IBS was 2.3% and the prevalence of depressive symptoms among nurses with IBS was 13.5%. Female nurses with IBS were 2.214 times more likely to experience increased stress levels. However, when demographics, dietary habits, sleep quality, and depressive symptoms were considered, having IBS was no longer an influential factor for increased stress levels. When all the variables were considered, female nurses with IBS were still 2.205 times more likely to experience depressive symptoms. Adequate support is needed to relieve depressive symptoms in nurses with IBS.

Group education on the low FODMAP diet improves gastrointestinal symptoms but neither anxiety or depression in irritable bowel syndrome

BACKGROUND

The low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet is an effective dietitian-led treatment for irritable bowel syndrome (IBS). An increasing demand of IBS patient referrals has warranted group FODMAP education led by specialist dietitians. Psychological co-morbidities are common in IBS, although how the low FODMAP diet influences psychological outcomes is not understood. The present study aimed to evaluate symptom related outcomes of the diet following group education and assess its effect on psychological profiles.

METHODS

An observational, prospective study was conducted in 55 IBS patients who attended FODMAP Restriction and FODMAP Reintroduction group sessions. Data were collected at baseline and follow-up after FODMAP Restriction and analysed using descriptive and McNemar's tests. Primary outcome was evaluated by IBS Symptom Severity Score (IBS-SSS). Secondary psychological outcomes included anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) and risk of eating disorder questionnaire (SCOFF).

RESULTS

After FODMAP Restriction, 27 of 55 (54%) patients reported clinically relevant symptom improvement, as defined by a reduction in the IBS-SSS ≥50 points, whereas no differences were recorded in the proportion of patients identified with clinical anxiety (p = 1.000) or clinical depression (p = 0.375). Positively, no increased risk of an eating disorder was observed.

CONCLUSIONS

The present study provides data supporting the efficacy of the low FODMAP diet in IBS patients who attended dietitian led group education settings in tertiary care. Clinically significant improvements in gastrointestinal symptoms were observed, although with no impact on clinical levels of anxiety, depression or the risk of an eating disorder.

Calcarine as a bridge between brain function and structure in irritable bowel syndrome: A multiplex network analysis

BACKGROUND AND AIM

Jointly analyzing structural and functional brain networks enables a better understanding of pathological underpinnings of irritable bowel syndrome (IBS). Multiplex network analysis provides a novel framework to study complex networks consisting of different types of connectivity patterns in multimodal data.

METHODS

In the present work, we integrated functional and structural networks to a multiplex network. Then, the multiplex metrics and the inner-layer/inter-layer hub nodes were investigated through 34 patients with IBS and 33 healthy controls.

RESULTS

Significantly differential multiplex degree in both left and right parts of calcarine was found, and meanwhile, IBS patients lost inner-layer hub properties in these regions. In addition, the left fusiform was no longer practicing as an inner-layer hub node, while the right median cingulate acted as a new inner-layer hub node in the IBS patients. Besides, the right calcarine, which lost its inner-layer hub identity, became a new inter-layer hub node, and the multiplex degree of the left hippocampus, which lost its inter-layer hub identity in IBS patients, was significantly positively correlated with the IBS Symptom Severity Score scores.

CONCLUSIONS

Inner-layer hub nodes of multiplex networks were preferentially vulnerable, and some inner-layer hub nodes would convert into inter-layer hub nodes in IBS patients. Besides, the inter-layer hub nodes might be influenced by IBS severity and therefore converted to general nodes.

Behavioral Strategies for Irritable Bowel Syndrome: Brain-Gut or Gut-Brain?

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction (DGBI) that is associated with significant physical, emotional, and occupational burden. Factors such as early life stress, sleep disruption, maladaptive coping strategies, symptom hypervigilance, and visceral hypersensitivity negatively affect gut-brain communication and increase the likelihood of developing IBS or worsen IBS severity. Behavioral strategies, such as cognitive behavioral therapy, gut-directed hypnosis, and mindfulness-based treatments, have shown benefit in improving gastrointestinal (GI)-specific quality of life, as well as reducing GI symptoms. Partnering with a GI-specific mental health provider can assist gastroenterologists in providing comprehensive treatment of IBS and other DGBIs.

Irritable Bowel Syndrome, Depression, and Neurodegeneration: A Bidirectional Communication from Gut to Brain

Patients with irritable bowel syndrome (IBS) are increasingly presenting with a wide range of neuropsychiatric symptoms, such as deterioration in gastroenteric physiology, including visceral hypersensitivity, altered intestinal membrane permeability, and gastrointestinal motor dysfunction. Functional imaging of IBS patients has revealed several abnormalities in various brain regions, such as significant activation of amygdala, thinning of insular and anterior cingulate cortex, and increase in hypothalamic gray matter, which results in poor psychiatric and cognitive outcomes. Interrelations between the enteric and central events in IBS-related gastrointestinal, neurological, and psychiatric pathologies have compelled researchers to study the gut-brain axis-a bidirectional communication that maintains the homeostasis of the gastrointestinal and central nervous system with gut microbiota as the protagonist. Thus, it can be disrupted by any alteration owing to the gut dysbiosis or loss of diversity in microbial composition. Available evidence indicates that the use of probiotics as a part of a balanced diet is effective in the management of IBS and IBS-associated neurodegenerative and psychiatric comorbidities. In this review, we delineate the pathogenesis and complications of IBS from gastrointestinal and neuropsychiatric standpoints while also discussing the neurodegenerative events in enteric and central nervous systems of IBS patients and the therapeutic potential of gut microbiota-based therapy established on clinical and preclinical data.

Pain and psyche in a patient with irritable bowel syndrome: chicken or egg? A time series case report

BACKGROUND

Irritable bowel syndrome (IBS) appears to have a bidirectional interaction with both depressive and anxiety-related complaints. However, it remains unclear how exactly the psychological complaints, at the individual level, are related to somatic symptoms on a daily basis. This single case study investigates how somatic and psychological variables are temporally related in a patient with irritable bowel syndrome.

CASE REPORT

The patient was a woman in her mid-twenties with an IBS diagnosis. She reported frequent soft bowel movements (5-6 times per day), as well as flatulence and abdominal pain. She resembled a typical IBS patient; however, a marked feature of the patient was her high motivation for psychosomatic treatment as well as her willingness to try new strategies regarding the management of her symptoms. As an innovative approach this single case study used a longitudinal, observational, time series design. The patient answered questions regarding somatic and psychological variables daily over a period of twelve weeks with an online diary. The diary data was analysed using an autoregressive (VAR) modeling approach. Time series analyses showed that in most variables, strong same-day correlations between somatic (abdominal pain, daily impairment) and psychological time series (including coping strategies) were present. The day-lagged relationships indicated that higher values in abdominal pain on one day were predictive of higher values in the psychological variables on the following day (e.g. nervousness, tension, catastrophizing, hopelessness). The use of positive thinking as a coping strategy was helpful in reducing the pain on the following days.

CONCLUSION

In the presented case we found a high correlation between variables, with somatic symptoms temporally preceding psychological variables. In addition, for this patient, the use of positive thoughts as a coping strategy was helpful in reducing pain.

Dietary Fibre Intervention for Gut Microbiota, Sleep, and Mental Health in Adults with Irritable Bowel Syndrome: A Scoping Review

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder affecting 4-5% of the global population. This disorder is associated with gut microbiota, diet, sleep, and mental health. This scoping review therefore aims to map existing research that has administrated fibre-related dietary intervention to IBS individuals and reported outcomes on at least two of the three following themes: gut microbiota, sleep, and mental health. Five digital databases were searched to identify and select papers as per the inclusion and exclusion criteria. Five articles were included in the assessment, where none reported on all three themes or the combination of gut microbiota and sleep. Two studies identified alterations in gut microbiota and mental health with fibre supplementation. The other three studies reported on mental health and sleep outcomes using subjective questionnaires. IBS-related research lacks system biology-type studies targeting gut microbiota, sleep, and mental health in patients undergoing diet intervention. Further IBS research is required to explore how human gut microbiota functions (such as short-chain fatty acids) in sleep and mental health, following the implementation of dietary pattern alteration or component supplementation. Additionally, the application of objective sleep assessments is required in order to detect sleep change with more accuracy and less bias.

The Role of Epigenomic Regulatory Pathways in the Gut-Brain Axis and Visceral Hyperalgesia

The gut-brain axis (GBA) is broadly accepted to describe the bidirectional circuit that links the gastrointestinal tract with the central nervous system (CNS). Interest in the GBA has grown dramatically over past two decades along with advances in our understanding of the importance of the axis in the pathophysiology of numerous common clinical disorders including mood disorders, neurodegenerative disease, diabetes mellitus, non-alcohol fatty liver disease (NAFLD) and enhanced abdominal pain (visceral hyperalgesia). Paralleling the growing interest in the GBA, there have been seminal developments in our understanding of how environmental factors such as psychological stress and other extrinsic factors alter gene expression, primarily via epigenomic regulatory mechanisms. This process has been driven by advances in next-generation multi-omics methods and bioinformatics. Recent reviews address various components of GBA, but the role of epigenomic regulatory pathways in chronic stress-associated visceral hyperalgesia in relevant regions of the GBA including the amygdala, spinal cord, primary afferent (nociceptive) neurons, and the intestinal barrier has not been addressed. Rapidly developing evidence suggests that intestinal epithelial barrier dysfunction and microbial dysbiosis play a potentially significant role in chronic stress-associated visceral hyperalgesia in nociceptive neurons innervating the lower intestine via downregulation in intestinal epithelial cell tight junction protein expression and increase in paracellular permeability. These observations support an important role for the regulatory epigenome in the development of future diagnostics and therapeutic interventions in clinical disorders affecting the GBA.

Gastrointestinal failure score in children with traumatic brain injury

BACKGROUND

To review the value of the gastrointestinal failure (GIF) score in children with different degrees of traumatic brain injury (TBI) by analyzing the correlation between outcome and gastrointestinal function.

METHODS

A total of 165 children with TBI who were diagnosed and treated in the surgical intensive care unit (SICU) for longer than 72 h between August 2017 and September 2019 were analyzed. Admission parameters included sex, age, Glasgow Coma Scale (GCS) score, body mass index (BMI), leukocyte count, C-reactive protein (CRP), hemoglobin (Hb), hematocrit (Hct), blood glucose, lactic acid, procalcitonin (PCT), albumin, plasma osmotic pressure, prothrombin time (PT) and activated partial thromboplastin time (APTT). To predict outcomes, the Pediatric Sequential Organ Failure Assessment (SOFA) score, Pediatric Clinical Illness Score (PCIS), and mean GIF score for the first three days were combined.

RESULTS

The percentage of patients with gastrointestinal dysfunction on the first day was 78.8 %. Food intolerance (FI) and intra-abdominal hypertension (IAH) developed in 36.4 and 21.8 % of the patients, respectively. The GIF score and mean GIF score for the first three days were significantly different between children with different degrees of TBI (P < 0.05); these scores were also significantly different between patients who died and those who survived (P < 0.05). The mean GIF score for the first three days was identified as an independent risk factor for mortality (odds ratio > 1, 95 % confidence interval = 1.457 to 16.016, P < 0.01), as was the PCIS. Receiver operating characteristic (ROC) curve analysis suggested that the mean GIF score for the first three days had the same calibrating power as the PCIS in discriminating the risk of death of children.

CONCLUSIONS

The incidence of gastrointestinal dysfunction in children with TBI is high. The GIF score has the ability to reflect the status of the gastrointestinal system. The mean GIF score for the first three days has high prognostic value for ICU mortality in the SICU.

Associations of Abdominal Pain and Psychosocial Distress Measures With Health-Related Quality-of-Life in Pediatric Healthy Controls and Irritable Bowel Syndrome

BACKGROUND

Children with irritable bowel syndrome (IBS) have lower health-related quality-of-life (HRQOL) than healthy controls (HC). Abdominal pain and psychosocial distress are negatively associated with HRQOL, although their relative effect is unclear.

AIM

The aim of this study was to compare the relative associations of abdominal pain and psychosocial distress with HRQOL in HC and IBS.

STUDY

Baseline abdominal pain, psychosocial distress, and HRQOL measures were obtained from HC and IBS pediatric clinical trial participants. Regression assessed which measures were most strongly associated with Physical and Psychosocial HRQOL separately by group. Interaction analyses examined group differences in the associations of abdominal pain and psychosocial distress with HRQOL.

RESULTS

Eight-five HC and 213 children with IBS participated. Somatization was most strongly associated with Physical HRQOL in HC, and functional disability was most strongly related in IBS. With respect to Psychosocial HRQOL, somatization was most strongly associated for both HC and IBS; depression was also significantly associated in HC. The strength of association between somatization and Physical HRQOL differed between groups; the negative association was less pronounced for IBS than HC. The association between functional disability and both Physical and Psychosocial HRQOL differed significantly between groups; the negative associations were more pronounced for IBS than HC.

CONCLUSIONS

Multiple psychosocial distress measures, including somatization, were associated with HRQOL in children with IBS; HRQOL in HC was driven consistently by somatization, to the exclusion of other psychosocial concerns. The associations of somatization and functional disability with HRQOL are distinctly different between HC and IBS. This knowledge supports utilization of psychosocial interventions to improve overall well-being for children with IBS.

Psychological comorbidity in gastrointestinal diseases: Update on the brain-gut-microbiome axis

The high comorbidity of psychological disorders in both functional and organic gastrointestinal diseases suggests the intimate and complex link between the brain and the gut. Termed the brain-gut axis, this bidirectional communication between the central nervous system and enteric nervous system relies on immune, endocrine, neural, and metabolic pathways. There is increasing evidence that the gut microbiome is a key part of this system, and dysregulation of the brain-gut-microbiome axis (BGMA) has been implicated in disorders of brain-gut interaction, including irritable bowel syndrome, and in neuropsychiatric disorders, including depression, Alzheimer's disease, and autism spectrum disorder. Further, alterations in the gut microbiome have been implicated in the pathogenesis of organic gastrointestinal diseases, including inflammatory bowel disease. The BGMA is an attractive therapeutic target, as using prebiotics, probiotics, or postbiotics to modify the gut microbiome or mimic gut microbial signals could provide novel treatment options to address these debilitating diseases. However, despite significant advancements in our understanding of the BGMA, clinical data is lacking. In this article, we will review current understanding of the comorbidity of gastrointestinal diseases and psychological disorders. We will also review the current evidence supporting the key role of the BGMA in this pathology. Finally, we will discuss the clinical implications of the BGMA in the evaluation and management of psychological and gastrointestinal disorders.

Cumulative Effect of Psychological Alterations on Gastrointestinal Symptom Severity in Irritable Bowel Syndrome

INTRODUCTION

Psychological alterations are common and considered important for symptom generation in irritable bowel syndrome (IBS). However, the possible cumulative effect of having multiple psychological alterations on gastrointestinal (GI) symptom severity in IBS is largely unknown.

METHODS

Patients with IBS (Rome IV) completed validated questionnaires assessing GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version and IBS Severity Scoring System), personality traits (Big Five), posttraumatic stress and psychological alterations, anxiety (Generalized Anxiety Disorder 7-item scale and State-Trait Anxiety Inventory), depression (Patient Health Questionnaire, 9-item version), fatigue (Multidimensional Fatigue Inventory), pain catastrophizing, somatization (Patient Health Questionnaire, 12-item version), stress (Perceived Stress Scale), and GI-specific anxiety (Visceral Sensitivity Index). Of the 18 possible psychological factors, those with significant associations with GI symptom severity, corrected for multiple comparisons, were identified. The associations between increasing number of psychological alterations (validated cutoff values or uppermost tertile) and the severity of GI symptoms were analyzed with linear trend analyses.

RESULTS

In total, 106 patients with IBS (Rome IV criteria) were included (72 [68%] women, median age of 35 [interquartile range: 26-45] years). Psychological alterations were common and overlap among these factors were frequently seen. Five psychological factors (physical fatigue, GI-specific anxiety, perceived stress, pain catastrophizing, and trait anxiety) demonstrated significant, noncollinear associations with GI symptom severity. With increasing number of these psychological alterations, a gradual increase was seen in the overall severity of GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version: partial η = 0.268, P < 0.001; IBS Severity Scoring System: partial η = 0.219, P < 0.001, both large effect sizes).

DISCUSSION

Distinct associations were seen between the severity of GI symptoms and individual, as well as an increasing number of psychological alterations. This highlights the importance of understanding different psychological alterations for the disease burden in IBS (visual abstract, Supplementary Digital Content 1, http://links.lww.com/AJG/B756).

Sex- and Gender-Related Differences in Common Functional Gastroenterologic Disorders

Functional gastrointestinal (GI) disorders (FGIDs) result from central and peripheral mechanisms, cause chronic remitting-relapsing symptoms, and are associated with comorbid conditions and impaired quality of life. This article reviews sex- and gender-based differences in the prevalence, pathophysiologic factors, clinical characteristics, and management of functional dyspepsia (FD) and irritable bowel syndrome (IBS) that together affect approximately 1 in 4 people in the United States. These conditions are more common in women. Among patients with IBS, women are more likely to have severe symptoms and coexistent anxiety or depression; constipation or bloating and diarrhea are more common in women and men, respectively, perhaps partly because defecatory disorders, which cause constipation, are more common in women. Current concepts suggest that biological disturbances (eg, persistent mucosal inflammation after acute gastroenteritis) interact with other environmental factors (eg, abuse) and psychological stressors, which influence the brain and gut to alter GI tract motility or sensation, thereby causing symptoms. By comparison to a considerable understanding of sex-based differences in the pathogenesis of visceral hypersensitivity in animal models, we know less about the contribution of these differences to FGID in humans. Slow gastric emptying and colon transit are more common in healthy women than in men, but effects of gonadal hormones on colon transit are less important than in rodents. Although increased visceral sensation partly explains symptoms, the effects of sex on visceral sensation, colonic permeability, and the gut microbiome are less prominent in humans than rodents. Whether sex or gender affects response to medications or behavioral therapy in FD or IBS is unclear because most patients in these studies are women.

Of bowels, brain and behavior: A role for the gut microbiota in psychiatric comorbidities in irritable bowel syndrome

BACKGROUND

The gastrointestinal microbiota has emerged as a key regulator of gut-brain axis signalling with important implications for neurogastroenterology. There is continuous bidirectional communication between the gut and the brain facilitated by neuronal, endocrine, metabolic, and immune pathways. The microbiota influences these signalling pathways via several mechanisms. Studies have shown compositional and functional alterations in the gut microbiota in stress-related psychiatric disorders. Gut microbiota reconfigurations are also a feature of irritable bowel syndrome (IBS), a gut-brain axis disorder sharing high levels of psychiatric comorbidity including both anxiety and depression. It remains unclear how the gut microbiota alterations in IBS align with both core symptoms and these psychiatric comorbidities.

METHODS

In this review, we highlight common and disparate features of these microbial signatures as well as the associated gut-brain axis signalling pathways. Studies suggest that patients with either IBS, depression or anxiety, alone or comorbid, present with alterations in gut microbiota composition and harbor immune, endocrine, and serotonergic system alterations relevant to the common pathophysiology of these comorbid conditions.

KEY RESULTS

Research has illustrated the utility of fecal microbiota transplantation in animal models, expanding the evidence base for a potential causal role of disorder-specific gut microbiota compositions in symptom set expression. Moreover, an exciting study by Constante and colleagues in this issue highlights the possibility of counteracting this microbiota-associated aberrant behavioral phenotype with a probiotic yeast, Saccharomyces boulardii CNCM I-745.

CONCLUSIONS AND INFERENCES

Such data highlights the potential for therapeutic targeting of the gut microbiota as a valuable strategy for the management of comorbid psychiatric symptoms in IBS.

Impact of Diet on Symptoms of the Irritable Bowel Syndrome

Irritable bowel syndrome (IBS), with its key features of abdominal pain and disturbed bowel habit, is thought by both patients and clinicians to be strongly influenced by diet. However, the complexities of diet have made identifying specific food intolerances difficult. Eating disorders can masquerade as IBS and may need specialist treatment. While typical food allergy is readily distinguished from IBS, the mechanisms of gut-specific adverse reactions to food are only just being defined. These may include gut-specific mast cell activation as well as non-specific activation by stressors and certain foods. Visceral hypersensitivity, in some cases mediated by mast cell activation, plays a key part in making otherwise innocuous gut stimuli painful. Rapidly fermented poorly absorbed carbohydrates produce gaseous distension as well as short-chain fatty acids and lowering of colonic pH which may cause symptoms in IBS patients. Limiting intake of these in low FODMAP and related diets has proven popular and apparently successful in many patients. Existing diet, colonic microbiota and their metabolic products may be helpful in predicting who will respond. Wheat intolerance may reflect the fact that wheat is often a major source of dietary FODMAPs. It may also be either a forme fruste of coeliac disease or non-specific immune activation. Wheat exclusion can be successful in some of these patients. More research is needed to fully understand the mechanisms of food intolerances and how to best ameliorate them in a personalised medicine approach to diet in IBS.

Symptom-network dynamics in irritable bowel syndrome with comorbid panic disorder using electronic momentary assessment: A randomized controlled trial of escitalopram vs. placebo

INTRODUCTION

Momentary ecological assessment indicated alleviated abdominal pain in escitalopram treatment of irritable bowel syndrome (IBS) with comorbid panic disorder. Hitherto, little is known about symptom formation, i.e., how psychological impact physical symptoms, and vice versa, and about the effect of SSRI-treatment on symptom formation.

OBJECTIVE

To investigate how psychological and somatic symptoms co-vary over time in IBS patients with comorbid panic disorder and how they are affected by escitalopram treatment.

METHODS

Experience sampling data from 14 IBS patients with panic disorder were obtained from a single-centre, double-blind, parallel-group, randomized controlled trial on escitalopram versus placebo. At baseline, after three and six months, multilevel time-lagged linear regression analysis was used to construct symptom networks. Network connections represented coefficients between various affect and gastrointestinal items.

RESULTS

Connectivity increased up to 3 months in both groups. Between 3 and 6 months, connectivity decreased for placebo and further increased in the escitalopram group. Additionally, a steep increase in node strength for negative affect nodes was observed in the escitalopram network and the opposite for positive affect nodes. Over time, group symptom networks became increasingly different from each other. Anxious-anxious and enthusiastic-relaxed became significantly different between groups at 6 months. The connection that changed significantly in all analyses was anxious-anxious.

CONCLUSIONS

Escitalopram treatment was associated with changes in the symptom networks in IBS patients with panic disorder. While mood and physical symptoms improve over time, mainly connectivity between mood nodes changed, possibly pointing towards a healthier emotion regulation resulting in alleviation of physical symptoms.

The effect of anxiety and depression on progression of glaucoma

Glaucoma is considered a chronic disease that requires lifelong management. Chronic diseases are known to be highly associated with psychological disturbances such as depression and anxiety. There have also been many studies on association between anxiety or depression and glaucoma. The majority of these studies explained that the glaucoma diagnosis causes anxiety or depression. However, It is also necessary to evaluate whether the psychological disturbance itself affect glaucoma. Therefore, we investigated the association of anxiety and depression with glaucoma progression, and elucidate mechanisms underlying that. We included 251 eyes with open angle glaucoma who were followed up for at least 2 years in this retrospective case-control study. The Beck Anxiety Inventory (BAI) and Beck Depressive Inventory-II (BDI-II) were used to assess anxiety and depression in glaucoma patients. Patients were classified into groups (high-anxiety group; HA-G, low-anxiety group; LA-G, high-depression group; HD-G, low-depression group; LD-G) according to their score on the BAI or BDI-II (separately). In logistic regression analysis, disc hemorrhage, peak intraocular pressure (IOP) and RNFL thickness loss rate were significantly associated with high anxiety (p = 0.017, p = 0.046, p = 0.026). RNFL thinning rate and disc hemorrhage were significant factors associated with anxiety in multivariate models (p = 0.015, p = 0.019). Multivariate linear regression analysis showed a significant positive correlation between the rate of RNFL thickness loss and BAI score (B = 0.058; 95% confidential interval = 0.020-0.097; p = 0.003), and RNFL loss and IOP fluctuation (B = 0.092; 95% confidential interval = 0.030-0.154; p = 0.004). For the depression scale, visual field mean deviation and heart rate variability were significantly associated with high depression in multivariate logistic regression analysis (p = 0.003, p = 0.006). We suggest that anxiety increase the risk of glaucoma progression and they are also associated with IOP profile and disc hemorrhage.

Association of Peroxiredoxin 1 and brain-derived neurotrophic factor serum levels with depression and anxiety symptoms in patients with irritable bowel syndrome

BACKGROUND

Oxidative stress is considered a possible mechanism of irritable bowel syndrome (IBS) and depression. This study determined the possible association of serum peroxiredoxin 1 (PRDX1; a key antioxidant enzyme) and brain-derived neurotrophic factor (BDNF) with anxiety and depression symptoms in IBS patients.

METHODS

According to the Rome IV diagnostic criteria, 177 IBS patients from February 2019 to July 2019 were included. Serum levels of PRDX1, BDNF, and TNFα were detected by enzyme-linked immunosorbent assay. Levels of anxiety and depression were assessed with the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS).

RESULTS

Compared with normal IBS patients, patients with anxiety and depression symptoms had significantly higher serum PRDX1 (p<0.001; p=0.002) and TNFα (p<0.001; p = 0.002) and significantly lower BDNF (p < 0.001; p = 0.002). Serum PRDX1 (r = 0.659, p < 0.001; r = 0.466, p < 0.001) and TNFα (r = 0.531, p < 0.001; r = 0.449, p < 0.001) were positively correlated with SAS and SDS, respectively, whereas BDNF was negatively correlated with SAS (r = 0.594, p < 0.001) and SDS (r = 0.534, p < 0.001). Multivariable regression analysis revealed that IBS severity, BDNF, and PRDX1 were significant predictors of anxiety. BDNF was also a significant predictor of depression.

CONCLUSION

Elevated PRDX1 and decreased BDNF in serum may be closely related to psychological symptoms in IBS. Results of this study suggested that PRDX1 may be an important target for IBS treatment in fighting against intestinal and psychological symptoms.

Prevalence of Subthreshold Depression Among Constipation-Predominant Irritable Bowel Syndrome Patients

Patients suffering from irritable bowel syndrome (IBS) may have some form of affective disorders that may worsen their symptoms. Lack of screening among IBS patients is one of the reasons for depression unawareness among healthcare providers. The present study was conducted to evaluate the prevalence of depression among patients with constipation-predominant IBS (IBS-C). A total of 240 IBS patients who fulfilled Rome III criteria were enrolled. The psychiatric assessment was evaluated using the Center for Epidemiologic Studies Depression Scale Revised (CESD-R). Twenty items in CESD-R scale measured symptoms of depression in nine separate groups. Patients were categorized into five different subgroups: major depressive episode, probable major depressive episode, possible major depressive episode, subthreshold depressive symptoms, and without clinical significance of depression. Out of the 240 patients with IBS-C, the majority (n = 161, 67.1%) had no clinical significance of depression. Seventy seven (32.1%) had subthreshold depression and only two (0.83%) patients were regarded as having probable a major depressive episode. No patient was categorized into a major or possible major depressive episode. The prevalence of subthreshold depression was the highest among female (72.3%) patients with 51.1% being single, 44.7% were married, and 4.3% were divorcees. When stratified according to ethnicity, subthreshold depression was highly prevalent among Malays (76.6%), followed by Chinese (19.2%), and Indians (2.1%). A high percentage of the patients were found to be non-smokers (93.6%) and had lower income of less than RM 5000 (USD 1250) per month (89.4%). The moderately high prevalence of subthreshold depression among patients with IBS, justifies psychological evaluation in all patients with functional gastrointestinal disorders.

Anxiety-related factors associated with symptom severity in irritable bowel syndrome

BACKGROUND

Gastrointestinal symptom-specific anxiety and somatization have both been associated with higher symptom severity in patients with irritable bowel syndrome (IBS); however, this relationship has not been explored fully. Moreover, the performance of the visceral sensitivity index (VSI) for measuring gastrointestinal symptom-specific anxiety has not been examined in a UK population. We conducted a cross-sectional survey to examine these issues.

METHODS

Gastrointestinal symptom-specific anxiety was measured using the VSI, and somatization was measured via the patient health questionnaire-12 (PHQ-12) in adults from the UK community with Rome IV-defined IBS. Exploratory factor analysis was performed on the VSI, prior to subsequent analyses, to establish its factor structure. Multiple regression analysis was used to determine the relationship between demographic features, different factors of the VSI, somatization, and IBS symptom severity.

KEY RESULTS

A total of 811 individuals with IBS provided complete data. Factor analysis of the VSI revealed a three-factor structure, accounting for 47% of the variance. The first of these VSI factors and the PHQ-12 were both strongly and independently associated with IBS symptom severity, for the group as a whole and for all four IBS subtypes. Most VSI items concerned with overt gastrointestinal symptom-specific anxiety loaded onto the other two VSI factors that were not associated with symptom severity.

CONCLUSIONS AND INFERENCES

The factor structure of the VSI requires further investigation. Our findings cast doubt on the central role of gastrointestinal symptom-specific anxiety as a driver for symptom severity in IBS. Awareness of both gastrointestinal and extra-intestinal symptoms, however, is strongly associated with symptom severity.