Systematic review with meta-analysis: the prevalence of anxiety and depression in patients with irritable bowel syndrome

Causal relationships between psychological disorders and functional gastrointestinal disorders: a bidirectional two-sample Mendelian randomization study

BACKGROUND AND AIMS

Observational studies have shown bidirectional associations between psychological disorders (e.g. depression and anxiety) and functional gastrointestinal disorders. However, whether the relationships are causal is uncertain. Here, we used a bidirectional two-sample Mendelian randomization method to investigate the association between psychological disorders and functional gastrointestinal disorders (FGIDs).

METHODS

We obtained genome-wide association study summary statistics for two common psychological disorders: depression (170 756 cases) and anxiety (31 977 cases), as well as for three common FGIDs: functional dyspepsia with 6666 cases, constipation with 26 919 cases, and irritable bowel syndrome (IBS) with 7053 cases. These summary statistics were retrieved from several publicly available genome-wide association study databases. The inverse variance weighted method was used as the main Mendelian randomization method.

RESULTS

Inverse variance weighted Mendelian randomization analyses showed statistically significant associations between genetically predicted depression and risk of functional dyspepsia [odds ratio (OR): 1.40, 95% confidence interval (CI): 1.08-1.82], constipation (OR: 1.28, 95% CI: 1.13-1.44), and IBS (OR: 1.51, 95% CI: 1.37-1.67). Genetically predicted anxiety was associated with a higher risk of IBS (OR: 1.13, 95% CI: 1.10-1.17) instead of functional dyspepsia and constipation. In addition, genetically predicted IBS instead of functional dyspepsia and constipation was associated with a higher risk of depression (OR: 1.33, 95% CI: 1.12-1.57) and anxiety (OR: 2.05, 95% CI: 1.05-4.03).

CONCLUSION

Depression is a causal risk factor for three common FGIDs. A bidirectional causal relationship between IBS and anxiety or depression was also identified.

Prevalence of depression or depressive state in patients with restless legs syndrome: A systematic review and meta-analysis

Restless legs syndrome (RLS) is a common sleep-related disorder characterized by limb discomfort and the urge to move them when at rest, especially in the evening or at night. Although depression is often linked to various conditions, no systematic review has assessed depression prevalence in patients with RLS after the latest diagnostic criteria revision. This systematic review and meta-analysis aimed to investigate the depression and depressive state prevalence among patients with RLS. We systematically searched databases up to November 2022 and performed meta-analyses of the depression prevalence using a random-effects model and a meta-regression analysis to explore the relationship between the prevalence and severity of depression and factors such as age and RLS severity. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we analyzed 24 studies with 2039 patients. The pooled depression or depressive state prevalence, mostly defined by questionnaire scores, was 30.39 %. Nine studies reported the proportion of patients taking antidepressants (pooled rate: 3.41 %). No specific factors related to the prevalence or severity of depression were identified in patients with RLS. These findings highlight the significant prevalence of depression and underscore the need for future research with standardized diagnostic interviews and consistent methodologies across multi-site studies.

Shared and distinct aberrations in frontal-striatal system functional patterns among patients with irritable bowel syndrome and major depressive disorder

BACKGROUND

Considering the high comorbidity, shared risk factors, and genetic pathways between irritable bowel syndrome (IBS) and major depressive disorder (MDD), we hypothesized that there would be both shared and disorder-specific alterations in brain function.

METHODS

A total of 39 IBS patients, 39 MDD patients, and 40 healthy controls (HCs) were enrolled and matched for sex, age, and educational level. All subjects underwent resting-state functional MRI. The clinical variables of anxiety, depression, gastrointestinal symptoms and alexithymia were recorded. The 12 subregions of the striatum were employed as seeds to assess their functional connectivity (FC) with every voxel throughout the whole brain.

RESULTS

Compared to HC, IBS and MDD patients exhibited aberrant frontal-striatal circuitry. We observed a common decrease in FC between the dorsal striatum and regions of the hippocampus, sensorimotor cortex, and prefrontal cortex (PFC) in both IBS and MDD patients. Patients with IBS exhibited disorder-specific decreases in FC within the striatum, along with reduced connectivity between the ventral striatum and sensorimotor cortex. In contrast, MDD patients showed disorder-specific hyperconnectivity in the medial PFC-limbic system. Receiver operating characteristic curve analysis showed that frontal-striatal FC values could serve as transdiagnostic markers of IBS and MDD. Within the IBS group, striatal connectivity was not only negatively associated with weekly abdominal pain days but also negatively correlated with the levels of anxiety and alexithymia.

CONCLUSIONS

This exploratory analysis indicated that patients with IBS and MDD exhibited both shared and disorder-specific frontal-striatal circuit impairments, potentially explaining both comorbidity and distinct phenotypes.

Effect of Lacticaseibacillus rhamnosus IDCC 3201 on irritable bowel syndrome with constipation: a randomized, double-blind, and placebo-controlled trial

Irritable bowel syndrome is a chronic disorder affecting the gastrointestinal tract, negatively impacting patients' quality of life. Here, we aimed to evaluate the effects of Lacticaseibacillus rhamnosus IDCC 3201 (RH 3201) on irritable bowel syndrome with constipation (IBS-C). In this randomised, double-blind, placebo-controlled trial, a total of 30 subjects with IBS-C were randomly assigned (1:1) to receive 8 weeks of probiotics administration or placebo. Concerning bowel activities, both irritant bowel movements and discomfort caused by constipation showed significant improvement with RH 3201 at 8 weeks. Symptoms including severity of abdominal bloating, frequency of abdominal bloating, and satisfaction of bowel habits based on the irritable bowel syndrome-severity scoring system also ameliorated in the probiotic group. Analysis of the fecal microbiome revealed that the abundance of Bacteroides cellulosilyticus and Akkermansia muciniphila was higher during the period of RH 3201 administration compared to the placebo. Untargeted metabolome analysis further suggested a correlation between specific metabolites, such as N-acetylornithine, xanthine, and 3-phenylpropionic acid, and the improvement of clinical symptoms. These results indicate that RH 3201 was effective in ameliorating IBS-C, potentially by enriching beneficial microbes and associated metabolites in the gut environment.

Connecting the dots: Network structures of internalizing and functional symptoms in a population-based cohort

OBJECTIVE

Comorbidities between internalizing disorders (IDs) and functional disorders (FDs) are well-documented, indicating shared pathways. However, their symptom-level relationships have been largely unexplored. This exploratory study employs a network approach to investigate symptoms of major depressive disorder (MDD), generalized anxiety disorder (GAD), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), and irritable bowel syndrome (IBS) to identify bridge symptoms explaining comorbidity between the two domains.

METHODS

We used cross-sectional data on 72,919 adult subjects from the Lifelines Cohort Study, a Dutch general population sample. A total of 38 symptoms representing diagnostic criteria of IDs and FDs were assessed with validated questionnaires. Network models were estimated using eLasso, based on the Ising model, to identify bridge symptoms. The Network Comparison Test (NCT) was used to test whether there were differences in network structure and strength across sex and age.

RESULTS

Symptoms were moderately connected, with a network density of 52.7%. ID and FD symptoms clustered in their respective domains, but were connected through the bridge symptoms, fatigue, difficulty concentrating, trouble sleeping, and unrefreshing sleep. Fatigue and difficulty concentrating had the most connections, associated with 86.6% and 78.9% of the other symptoms, respectively. NCTs indicated no differences in network connectivity between females versus males or younger versus older adults (>50 years).

CONCLUSIONS

ID and FD symptoms are moderately interconnected. Bridge symptoms displaying strong connections to multiple disorders may play a central role in the mechanisms underpinning the comorbidity between IDs and FDs.

Association between psychiatric disorders and irritable bowel syndrome: A bidirectional Mendelian randomization study

OBJECTIVE

Previous studies have suggested that irritable bowel syndrome (IBS) is strongly associated with psychiatric disorders. However, it is unclear whether this association is causal, concomitant, or accidental. Thus, we performed Mendelian randomization (MR) analysis to evaluate the causal effects of several psychiatric disorders on IBS.

METHODS

Summary data of genome-wide association studies (GWASs) were obtained mainly from the Psychiatric Genomics Consortium (PGC) on individuals of European ancestry and from a recent GWAS on IBS. We used three MR methods, the inverse-variance weighting (IVW), weighted median (WM), and MR-Egger regression (MR-Egger). In addition, two other indicators, namely, the MR-IVW Cochran's Q statistic and MR-Egger intercept, were used to assess heterogeneity and detect directional horizontal pleiotropy, respectively.

RESULTS

Heritability was high for bipolar disorder (81.18 %, 95 % CI = 73.18-148.18 %), schizophrenia (33.88 %, 95 % CI = 33.57-38.19 %), and panic disorder (30.66 %, 95 % CI = 20.74-40.58 %). For other disorders, there was a low liability-scale SNP heritability for major depressive disorder (MDD) (0.67 %, 95 % CI = 0.61-0.73 %), anxiety disorder (7.63 %, 95 % CI = 1.67-13.59 %), PTSD (0.96 %, 95 % CI = 0.12-1.8 %), and IBS (2.44 %, 95 % CI = 2.13-2.75 %). We also observed that schizophrenia had a significant causal effect on IBS according to MR-IVW. Notably, the individual causal estimates of genetic instruments for MDD and schizophrenia were heterogeneous, but no pleiotropic effects were observed.

CONCLUSIONS

Our analyses revealed the causal effects of MDD and schizophrenia on IBS, a matter that has been subject to debate for decades, and also showed that IBS had causal effects on MDD.

Burden of illness and treatment attitudes among participants meeting Rome IV criteria for irritable bowel syndrome: A nationwide survey in the United States

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by abdominal pain and altered bowel habits, with patient-perceived dissatisfaction of treatment symptom control. We assessed disease burden, satisfaction with medication use, and impact on activities, in participants with IBS with constipation (IBS-C) and diarrhea (IBS-D).

METHODS

This study assessed data from a large, United States survey of adults querying demographics, comorbid conditions, quality of life, medication use, satisfaction with symptom control, and work productivity. Participants were grouped into the IBS-C or IBS-D cohort if they met Rome IV criteria, with controls matched 1:1 according to age, sex, race, region, and Charlson Comorbidity Index score. All data were self-reported.

KEY RESULTS

Nine hundred and ten participants with IBS-C and 669 with IBS-D were matched to controls. The most reported symptoms were abdominal discomfort for IBS-C and abdominal pain and abdominal discomfort for IBS-D. Among the IBS-C and IBS-D cohorts, 74.2% and 65.9%, respectively, took prescription and/or over-the-counter medication for their symptoms. Respondents were more dissatisfied than satisfied with control of their symptoms. Respondents taking prescription medication(s) with or without over-the-counter medication(s) reported better symptom control than respondents only taking over-the-counter medications (p < 0.001). There was significantly higher mean presenteeism, work productivity loss, and daily activity impairment (p < 0.001 for all) in respondents with IBS compared with controls.

CONCLUSIONS AND INFERENCES

This study provides insight into respondents' experiences of IBS symptoms, including the impact on daily activity, as well as satisfaction with control of symptoms and prescription and over-the-counter medications.

The impact of depression-mediated gut microbiota composition on Irritable Bowel Syndrome: A Mendelian study

OBJECTIVE

This study uses a two-sample Mendelian randomization (MR) analysis to delineate the causal influence of gut microbiota on the occurrence of irritable bowel syndrome (IBS), concurrently assessing the potential mediating function of depression within this framework.

METHODS

Several two-sample MR methods were used to assess the causal repercussions of gut microbiota on the onset of both IBS and depression. Following this, gut microbiota and depression, which demonstrated notable causal associations, were integrated as exposure variables in a multivariable Mendelian randomization (MVMR) framework to construct a model encompassing gut microbiota, depression, and IBS. Mediation effects were assessed by examining the indirect pathway of gut microbiota → depression → IBS.

RESULTS

Two-sample MR analysis unveiled a statistically significant causal association (P < 0.05) between specific bacterial group within the gut microbiota, notably p_Actinobacteria(OR = 0.829225), c_Clostridia(OR = 0.798897), s_Desulfovibrio_piger(OR = 1.163912), g_Streptococcus(OR = 1.132735), c_Actinobacteria(OR = 0.829224), and the onset of IBS. In the MVMR analysis, the relationship between depression and IBS was significant across Model 3, Model 7, Model 8, and Model 13 (P < 0.05). Assessment of mediation effects revealed that c_Clostridia and o_Clostridiales indirectly impacted IBS through depression, with masking effect ratios of 168.46 % and 168.44 %, respectively.

CONCLUSION

These findings underscore a resilient causal association between the composition of gut microbiota and the initiation of IBS. Furthermore, depression serves as a mediator for particular groups of gut bacteria, thereby contributing to the development of IBS. These observations imply that interventions targeting mental health may potentially alleviate the risk of IBS onset attributable to adverse configurations of gut microbiota.

Comorbidity and sex differences in functional disorders and internalizing disorders

OBJECTIVE

In the current exploratory study we estimate comorbidity rates between FDs [fibromyalgia (FM), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and irritable bowel syndrome (IBS)]-and IDs-[major depressive disorder (MDD) and generalized anxiety disorder (GAD)] by using self-reported diagnostic criteria.

METHOD

We analyzed data from 107,849 participants (mean age = 49.3 (SD = 13.0), 58.6% women) of the Lifelines Cohort Study. Lifelines is a prospective population-based cohort study in the northeast of the Netherlands. Current IDs were assessed using the Mini-International Neuropsychiatric Interview. Current FM, ME/CFS, and IBS were assessed according to the 2010 American College of Rheumatology criteria, the 1994 Centers for Disease Control and Prevention criteria and the ROME IV criteria, respectively. We estimated tetrachoric correlations between diagnoses and tested for sex differences. Additionally, we estimated the ratio of observed-to-expected frequency for combinations of diagnoses.

RESULTS

FDs and IDs are highly comorbid (odds ratios: 3.2-12.6) with associations stronger among men. Participants with at least three disorders/diagnoses were more prevalent than expected by chance.

CONCLUSION

Studies that aim to explain sex differences and the comorbidity of specific combinations of IDs and FDs will be an important contribution to understanding the etiology of these conditions.

Effects of Physical Exercise on the Microbiota in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by abdominal pain, bloating, diarrhea, and constipation. Recent studies have underscored the significant role of the gut microbiota in the pathogenesis of IBS. Physical exercise, as a non-pharmacological intervention, has been proposed to alleviate IBS symptoms by modulating the gut microbiota. Aerobic exercise, such as running, swimming, and cycling, has been shown to enhance the diversity and abundance of beneficial gut bacteria, including Lactobacillus and Bifidobacterium. These bacteria produce short-chain fatty acids that possess anti-inflammatory properties and support gut barrier integrity. Studies involving IBS patients participating in structured aerobic exercise programs have reported significant improvements in their gut microbiota's composition and diversity, alongside an alleviation of symptoms like abdominal pain and bloating. Additionally, exercise positively influences mental health by reducing stress and improving mood, which can further relieve IBS symptoms via the gut-brain axis. Long-term exercise interventions provide sustained benefits, maintaining the gut microbiota's diversity and stability, supporting immune functions, and reducing systemic inflammation. However, exercise programs must be tailored to individual needs to avoid exacerbating IBS symptoms. Personalized exercise plans starting with low-to-moderate intensity and gradually increasing in intensity can maximize the benefits and minimize risks. This review examines the impact of various types and intensities of physical exercise on the gut microbiota in IBS patients, highlighting the need for further studies to explore optimal exercise protocols. Future research should include larger sample sizes, longer follow-up periods, and examine the synergistic effects of exercise and other lifestyle modifications. Integrating physical exercise into comprehensive IBS management plans can enhance symptom control and improve patients' quality of life.

Barriers to Engagement with Gastrointestinal Health Management

BACKGROUND

Although behavioral interventions have been effective in gastrointestinal (GI) conditions, barriers exist in implementing these interventions into clinical practice. The majority of previously published studies have focused on workforce limitations and have not considered individual and social determinants of health (SDoH) factors that can impact engagement in GI behavioral healthcare.

AIMS

To characterize barriers to engagement in appointment attendance and health management, explore individual and SDoH factors impacting GI behavioral healthcare engagement, and identify barriers that occur more often for patients with SDoH-related vulnerability (low health literacy and/or financial insecurity).

METHODS

A survey was distributed to adult patients who had been seen in Gastroenterology at the Dartmouth-Hitchcock Medical Center from June 2022 to December 2022.

RESULTS

One hundred participants [mean age = 58 years, 57.1% women] completed the survey. SDoH vulnerability was present in 32.3% of the population. For the entire sample, 73% reported at least one barrier to accessing care and 75% reported at least one factor which impacted health management. Those with SDoH vulnerability reported significantly more barriers to attending appointments and to managing health. In addition, they were significantly more likely to endorse physical health problems, difficulty affording medical bills, pain, mobility issues, trauma experiences, significant stress, and difficulty with concentration.

CONCLUSIONS

Patients in a GI clinic reported multiple barriers to accessing care and participating in health management. Innovative, multi-level strategies are needed to address barriers to ensure that all patients are able to obtain quality GI behavioral health services.

Review of the Patient Burden and Therapeutic Landscape of Irritable Bowel Syndrome with Constipation in the United States

Irritable bowel syndrome (IBS) is a common disorder of the gut-brain axis. IBS with constipation (IBS-C) accounts for approximately one-third of IBS cases and is associated with substantial burden of illness and decreased quality of life. This narrative review provides an overview of the current and upcoming treatment options and disease management for IBS-C from a US perspective and discusses the importance of the relationship between patient and health care provider in diagnosis and treatment. A positive diagnostic strategy for IBS-C is recommended, based on clinical history, physical examination, and minimal laboratory tests. An effective communication strategy between patients and health care professionals is essential to ensure early diagnosis and reduce both health care costs and overall disease burden. Treatment typically begins with lifestyle interventions and nonpharmacologic options, such as dietary interventions, fiber supplements, and osmotic laxatives. In patients with inadequate response to these therapies, 4 currently available therapies (lubiprostone, linaclotide, plecanatide, and tenapanor) approved by the US Food and Drug Administration may relieve IBS-C symptoms. These agents are generally well tolerated and efficacious in improving IBS-C symptoms, including constipation and abdominal pain. In patients with persistent abdominal pain and/or psychological symptoms, brain-gut behavioral therapy or neuromodulator therapy may be beneficial.

Irritable Bowel Syndrome in the Elderly Population: A Comprehensive Review

Irritable bowel syndrome (IBS) is a fairly common functional digestive disorder; it occurs at any age but it is more common in adults and older adults. Patients experience a series of symptoms in which abdominal pain and changes in bowel movements stand out; some studies have revealed a possible association between IBS and psychological problems, such as anxiety and depression. Recent findings point to disorders of gut-brain interaction, disruption and alteration of gut microbiota and dysbiosis as key factors in the etiopathogenesis of IBS; aging is also one the factors involved. Most patients diagnosed with IBS required pharmacotherapy, greater caution needs to be considered when treating older patients because of the risk-benefit profile in the elderly. In this scenario, probiotics and non-pharmacological treatments appear as safe and accessible options. Clinicians must take into consideration the unique biopsychosocial factors in older adults when treating IBS. We aim to review critically recent literature on the topic of IBS as there is a need for consolidated guidelines.

The COVID-19 pandemic as a modifier of DGBI symptom severity: A systematic review and meta-analysis

BACKGROUND

This SRMA reviewed and assessed the changes in the severity of disorders of gut-brain interaction (DGBI) symptoms during the COVID-19 pandemic, and evaluated factors associated with symptom severity changes.

METHODS

Electronic databases were searched until February 2024, for articles reporting on changes in symptom severity in DGBI patients during the COVID-19 pandemic. The proportion of DGBI patients who reported a change in their symptom severity were pooled using a random-effects model, and subgroup analyses were conducted to assess the effect of socio-cultural modifiers on symptom severity in DGBI.

KEY RESULTS

Twelve studies including 3610 DGBI patients found that 31.4% (95% CI, 15.9-52.5) of DGBI patients experienced symptom deterioration, while 24.3% (95% CI, 10.2-47.5) experienced improvement. Countries with high gross domestic product (GDP) had a 43.5% (95% CI, 16.3-75.2) likelihood of symptom deterioration, compared to 9.2% (95% CI, 1.4-42.2) in lower GDP countries. Similarly, countries with low COVID fatality rates had a 60.1% (95% CI, 19.7-90.3) likelihood of symptom deterioration, compared to 18.3% (95% CI, 7.8-36.9) in higher fatality rate countries. Countries with lenient COVID policies had a 58.4% (95% CI, 14.1-92.3) likelihood of symptom deterioration, compared to 19% (95% CI, 8.2-38.1) in countries with stricter policies. Patients in high vaccine hesitancy countries had a 51.4% (95% CI, 19.5-82.2) likelihood of symptom deterioration, compared to 10.6% (95% CI, 2.7-33.4) in low vaccine hesitancy countries.

CONCLUSIONS & INFERENCES

This meta-analysis reveals that a significantly higher proportion of DGBI patients experienced deterioration of symptoms during the COVID-19 pandemic. Various sociocultural, economic and environmental factors potentially modify the effects of the COVID-19 pandemic on DGBI.

Contemporary Perspectives on the Role of Vitamin D in Enhancing Gut Health and Its Implications for Preventing and Managing Intestinal Diseases

Vitamin D, a crucial fat-soluble vitamin, is primarily synthesized in the skin upon exposure to ultraviolet radiation and is widely recognized as a bone-associated hormone. However, recent scientific advancements have unveiled its intricate association with gut health. The intestinal barrier serves as a vital component, safeguarding the intestinal milieu and maintaining overall homeostasis. Deficiencies in vitamin D have been implicated in altering the gut microbiome composition, compromising the integrity of the intestinal mucosal barrier, and predisposing individuals to various intestinal pathologies. Vitamin D exerts its regulatory function by binding to vitamin D receptors (VDR) present in immune cells, thereby modulating the production of pro-inflammatory cytokines and influencing the intestinal barrier function. Notably, numerous studies have reported lower serum vitamin D levels among patients suffering from intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, and celiac disease, highlighting the growing significance of vitamin D in gut health maintenance. This comprehensive review delves into the latest advancements in understanding the mechanistic role of vitamin D in modulating the gut microbiome and intestinal barrier function, emphasizing its pivotal role in immune regulation. Furthermore, we consolidate and present relevant findings pertaining to the therapeutic potential of vitamin D in the management of intestinal diseases.

Genetic Variations in TrkB.T1 Isoform and Their Association With Somatic and Psychological Symptoms in Individuals With IBS

Irritable bowel syndrome (IBS), a disorder of gut-brain interaction, is often comorbid with somatic pain and psychological disorders. Dysregulated signaling of brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), has been implicated in somatic-psychological symptoms in individuals with IBS. We investigated the association of 10 single-nucleotide polymorphisms (SNPs) in the regulatory 3' untranslated region of neurotrophic receptor tyrosine kinase-2 (NTRK2) kinase domain-deficient truncated isoform (TrkB.T1) and BDNF Val66Met SNP with somatic and psychological symptoms and quality-of-life (QoL) in a cohort from the United States (IBS, n = 464; healthy controls, n = 156). We found that the homozygous recessive genotype (G/G) of rs2013566 in individuals with IBS is associated with worsened somatic symptoms, including headache, back pain, joint pain, muscle pain, and somatization as well as diminished sleep quality, energy level, and overall QoL. Validation using United Kingdom BioBank data confirmed the association of rs2013566 with an increased likelihood of headache. Several SNPs (rs1627784, rs1624327, and rs1147198) showed significant associations with muscle pain in our U.S. cohort. These 4 SNPs are predominantly located in H3K4Me1-enriched regions, suggesting their enhancer and/or transcription regulation potential. Our findings suggest that genetic variation within the 3' untranslated region region of the TrkB.T1 isoform may contribute to comorbid conditions in individuals with IBS, resulting in a spectrum of somatic and psychological symptoms impacting their QoL. These findings advance our understanding of the genetic interaction between BDNF/TrkB pathways and somatic-psychological symptoms in IBS, highlighting the importance of further exploring this interaction for potential clinical applications. PERSPECTIVE: This study aims to understand the genetic effects on IBS-related symptoms across somatic, psychological, and quality-of-life (QoL) domains, validated by United Kingdom BioBank data. The rs2013566 homozygous recessive genotype correlates with worsened somatic symptoms and reduced QoL, emphasizing its clinical significance.

Psychiatric Disorders Among 5,800 Patients With Microscopic Colitis: A Nationwide Population-Based Matched Cohort Study

INTRODUCTION

Microscopic colitis (MC) is an inflammatory condition of the large intestine. Primarily diagnosed in middle-aged and older adults, the incidence of the disease has increased markedly during the past few decades. While MC is associated with a reduced quality of life, large-scale studies on the association with future psychiatric disorders are lacking.

METHODS

We conducted a nationwide matched cohort study in Sweden from 2006 to 2021. Through a nationwide histopathology database (the Epidemiology Strengthened by histoPathology Reports in Sweden study), we identified 5,816 patients with a colorectal biopsy consistent with MC. These patients were matched with 21,509 reference individuals from the general population all of whom with no previous record of psychiatric disorders.

RESULTS

From 2006 to 2021, 519 patients with MC (median age 64.4 years [interquartile range = 49.5-73.3]) and 1,313 reference individuals were diagnosed with psychiatric disorders (9.9 vs 6.5 events per 1,000 person-years), corresponding to 1 extra case of psychiatric disorder in 29 patients with MC over 10 years. After adjustments, the hazard ratio for psychiatric disorders was 1.57 (95% confidence interval = 1.42-1.74). We found significantly elevated estimates up to 10 years after MC diagnosis and a trend toward higher risk with increasing age. Specifically, we observed increased risks for unipolar depression, anxiety disorders, stress-related disorders, substance abuse, and suicide attempts. In sibling-controlled analysis, the adjusted hazard ratio was 1.76 (95% confidence interval = 1.44-2.15).

DISCUSSION

Patients with MC are at increased risk of incident psychiatric disorders compared with the general population.

Genome-wide association study of major anxiety disorders in 122,341 European-ancestry cases identifies 58 loci and highlights GABAergic signaling

The major anxiety disorders (ANX; including generalized anxiety disorder, panic disorder, and phobias) are highly prevalent, often onset early, persist throughout life, and cause substantial global disability. Although distinct in their clinical presentations, they likely represent differential expressions of a dysregulated threat-response system. Here we present a genome-wide association meta-analysis comprising 122,341 European ancestry ANX cases and 729,881 controls. We identified 58 independent genome-wide significant ANX risk variants and 66 genes with robust biological support. In an independent sample of 1,175,012 self-report ANX cases and 1,956,379 controls, 51 of the 58 associated variants were replicated. As predicted by twin studies, we found substantial genetic correlation between ANX and depression, neuroticism, and other internalizing phenotypes. Follow-up analyses demonstrated enrichment in all major brain regions and highlighted GABAergic signaling as one potential mechanism underlying ANX genetic risk. These results advance our understanding of the genetic architecture of ANX and prioritize genes for functional follow-up studies.

Prevalence of Irritable Bowel Syndrome (IBS) in the Arab World: A Systematic Review

Irritable Bowel Syndrome (IBS) is a common functional pathology of the gastrointestinal tract (GIT) across the globe. The prevalence rate of IBS varies across the regions. In the present systematic review, we aim to investigate the prevalence of IBS in Arab countries in recent years. To identify relevant studies, a comprehensive search was undertaken in various databases including CINAHL (Cumulated Index to Nursing and Allied Health Literature) Ultimate, Scopus, PubMed, and Web of Science. Furthermore, Google Scholar was also explored to identify relevant studies. The inclusion criteria included studies that assessed IBS in the Arab world and were published in the English language. Fifty-two cross-sectional studies from seven countries, encompassing 51,683 participants, were included. The majority of the included studies were conducted in Saudi Arabia (n=40), followed by Jordan (n=4) and Egypt (n=3). The highest prevalence rates were reported by studies from Saudi Arabia, Lebanon, and Jordan. Low prevalence rates (<20%) were noted in 19 studies included in this systematic review. Female predominance in IBS prevalence was observed in most studies, while only two studies indicated higher prevalence in males. Key risk factors included family history, anxiety, depression, gastroesophageal reflux disease, low income, diabetes, low water intake, workload, occupation, food allergy, smoking, age, chronic diseases, and stress. IBS prevalence in the Arab world varies significantly. Female predominance was seen in the present systematic review as well.

Prevalence and Influencing Factors of Irritable Bowel Syndrome Among Nurses in China: A Cross-Sectional Study

The aims of this study were to investigate the prevalence and influencing factors of irritable bowel syndrome among nurses in order to update the epidemiological data. A questionnaire survey was administered to 1,325 clinical nurses. We used a questionnaire for demographic information, the IBS Severity Scoring System, the IBS Quality of Life questionnaire, the Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, and the Maslach Burnout Inventory to conduct our survey. Univariate and multivariate analyses were performed to detect factors influencing irritable bowel syndrome among nurses. The prevalence of irritable bowel syndrome was 13.3%, and the severity of symptoms was mostly moderate. The IBS Quality of Life score was significantly reduced (p < .001). Various foods that caused abdominal pain (egg and dairy products [OR = 4.80], greasy food [OR = 5.80], spicy food [OR = 2.66], raw and cold food [OR = 2.43]), a family history of gastrointestinal diseases (OR = 1.64, 95% CI [1.038, 2.587]), drinking weak green tea (OR = 1.71, 95% CI [1.143, 2.552]), mild depression (OR = 1.78, 95% CI [1.005, 3.156]), and the personal accomplishment dimension of occupational burnout (OR = 2.52, 95% CI [1.039, 6.114]) had important effects on nurses suffering from irritable bowel syndrome. On the contrary, exercising 1-2 hours per week (OR = 0.53, 95% CI [0.327, 0.859]) had a protective effect. The prevalence of irritable bowel syndrome among nurses is relatively high and may be influenced by several factors including genetics, diet, exercise, psychology, and occupational burnout.

Multipronged Electronic Health Record Analysis of Antidepressant Effectiveness on Depression Remission in Patients With Concurrent Depression and Irritable Bowel Syndrome

Background Patients with irritable bowel syndrome (IBS) often experience chronic abdominal pain and bowel habit changes, with a heightened risk of depression and anxiety compared to the general population. Methods Using TriNetX data from 61 U.S. healthcare organizations, we conducted a retrospective study of three electronic health record (EHR) analyses. We used International Classification of Diseases, Tenth Revision (ICD-10) and Anatomical Therapeutic Chemical Classification (ATC) codes to analyze depression remission among IBS patients, comparing those using antidepressants to those who were not and comparing outcomes among different types of medication. Statistical methods included risk difference, risk ratio, hazard ratio, Kaplan-Meier survival analysis, log-rank tests, and Cox hazard ratios Results Among 78,673 patients with both depression and IBS, those using antidepressants showed significantly higher rates of depressive remission compared to non-users: risk difference (RD), -0.056; risk ratio (RR), 0.380; and hazard ratio (HR), 0.413. Both atypical antidepressants bupropion and trazodone exhibited greater efficacy in achieving remission compared to selective serotonin reuptake inhibitors (SSRIs), sertraline and escitalopram. For SSRI vs bupropion, RD is -0.041, RR is 0.664, and HR is 0.655. For SSRIs vs trazodone, RD is -0.018 , RR is 0.822, and HR is 0.806. The comparative impact of bupropion versus trazodone on remission remains inconclusive. Conclusion Depression presents a significant comorbidity in IBS patients, with atypical antidepressants potentially offering superior efficacy in achieving remission compared to SSRIs. Further research should explore these medications' psychiatric outcomes in this population to better understand their therapeutic benefits beyond gastrointestinal (GI) symptoms.

Rome III and IV criteria are less discordant to diagnose irritable bowel syndrome in clinic patients than in community subjects

BACKGROUND

Though Rome IV criteria for irritable bowel syndrome (IBS) are less sensitive; they select Rome III patients with greater severity and consultation behavior. Since severity of IBS may determine consultation behavior, we compared Rome III and IV criteria in clinic patients and compared with earlier published data from Indian community hypothesizing that the diagnostic discordance between these criteria would be less in clinic than in community.

METHODS

Tertiary clinic patients were screened for IBS using Hindi translated-validated Rome III and IV questionnaires; IBS symptom severity scores (IBS-SSS) was also assessed. Diagnostic discordance between Rome III and IV criteria for IBS was compared with earlier published Indian community data.

RESULTS

Of 110 clinic patients with functional gastrointestinal disorders, 72 met IBS criteria (47 [42.7%], 22 [20%] and three [2.7%] both Rome III and IV criteria, Rome III criteria only and Rome IV criteria only, respectively). In contrast, of 40 IBS subjects from Indian community published earlier, nine (22.5%), 28 (70%) and three (7.5%) fulfilled both Rome III and IV, Rome III only, Rome IV only criteria, respectively. Clinic patients with IBS fulfilling both Rome III and IV criteria or Rome IV criteria had higher IBS-SSS than those fulfilling Rome III criteria only (295.3 ± 80.7 vs. 205.6 ± 65.7; p < 0.00001). This difference was primarily related to pain severity and number of days with pain.

CONCLUSION

Discordance between Rome IV and Rome III criteria in tertiary care clinic patients is less than in community subjects with IBS in India.

The role of the gut microbiome in disorders of gut-brain interaction

Disorders of Gut-Brain Interaction (DGBI) are widely prevalent and commonly encountered in gastroenterology practice. While several peripheral and central mechanisms have been implicated in the pathogenesis of DGBI, a recent body of work suggests an important role for the gut microbiome. In this review, we highlight how gut microbiota and their metabolites affect physiologic changes underlying symptoms in DGBI, with a particular focus on their mechanistic influence on GI transit, visceral sensitivity, intestinal barrier function and secretion, and CNS processing. This review emphasizes the complexity of local and distant effects of microbial metabolites on physiological function, influenced by factors such as metabolite concentration, duration of metabolite exposure, receptor location, host genetics, and underlying disease state. Large-scale in vitro work has elucidated interactions between host receptors and the microbial metabolome but there is a need for future research to integrate such preclinical findings with clinical studies. The development of novel, targeted therapeutic strategies for DGBI hinges on a deeper understanding of these metabolite-host interactions, offering exciting possibilities for the future of treatment of DGBI.

Management of Refractory Functional Gastrointestinal Disorders: What Role Should Psychiatrists Have?

Currently, it has been stated that psychiatric and psychological problems are equally paramount aspects of the clinical modulation and manifestation of both the central nervous and digestive systems, which could be used to restore balance. The present narrative review aims to provide an elaborate description of the bio-psycho-social facets of refractory functional gastrointestinal disorders, psychiatrists' role, specific psychiatric approach, and the latest psychiatric and psychological perspectives on practical therapeutic management. In this respect, "psyche," "psychiatry," "psychology," "psychiatrist," "psychotropic," and "refractory functional gastrointestinal disorders" (as the keywords) were searched in relevant English publications from January 1, 1950, to March 1, 2024, in the PubMed, Web of Science, Scopus, EMBASE, Cochrane Library, and Google Scholar databases. Eventually, the narrative technique was adopted to reach a compelling story with a high level of cohesion through material synthesis. The current literature recognizes the brain-gut axis modulation as a therapeutic target for refractory functional gastrointestinal disorders and the bio-psycho-social model as an integrated framework to explain disease pathogenesis. The results also reveal some evidence to affirm the benefits of psychotropic medications and psychological therapies in refractory functional gastrointestinal disorders, even when psychiatric symptoms were absent. It seems that psychiatrists are required to pay higher levels of attention to both the assessment and treatment of patients with refractory functional gastrointestinal disorders, accompanied by educating and training practitioners who take care of these patients.

Irritable Bowel Syndrome Is Associated With Brain Health by Neuroimaging, Behavioral, Biochemical, and Genetic Analyses

BACKGROUND

Irritable bowel syndrome (IBS) interacts with psychopathology in a complex way; however, little is known about the underlying brain, biochemical, and genetic mechanisms.

METHODS

To clarify the phenotypic and genetic associations between IBS and brain health, we performed a comprehensive retrospective cohort study on a large population. Our study included 171,104 participants from the UK Biobank who underwent a thorough assessment of IBS, with the majority also providing neuroimaging, behavioral, biochemical, and genetic information. Multistage linked analyses were conducted, including phenome-wide association analysis, polygenic risk score calculation, and 2-sample Mendelian randomization analysis.

RESULTS

The phenome-wide association analysis showed that IBS was linked to brain health problems, including anxiety and depression, and poor cognitive performance. Significantly lower brain volumes associated with more severe IBS were found in key areas related to emotional regulation and higher-order cognition, including the medial orbitofrontal cortex/ventromedial prefrontal cortex, anterior insula, anterior and mid-cingulate cortices, dorsolateral prefrontal cortex, and hippocampus. Higher triglycerides, lower high-intensity lipoprotein, and lower platelets were also related (p < 1 × 10-10) to more severe IBS. Finally, Mendelian randomization analyses demonstrated potential causal relationships between IBS and brain health and indicated possible mediating effects of dyslipidemia and inflammation.

CONCLUSIONS

For the first time, this study provides a comprehensive understanding of the relationship between IBS and brain health phenotypes, integrating perspectives from neuroimaging, behavioral performance, biochemical factors, and genetics, which is of great significance for clinical applications to potentially address brain health impairments in patients with IBS.

Role of Sex, Anxiety, and Resilience in the Association between Adverse Childhood Experiences and Irritable Bowel Syndrome

BACKGROUND & AIMS

Adverse childhood experiences (ACE) are associated with increased risk of irritable bowel syndrome (IBS), a female-predominant chronic abdominal disorder. Factors contributing to this association have not been well-studied. We compared sex differences in ACE for adults with and without IBS and evaluated the impact of anxiety and resilience on the relationship between ACE and IBS.

METHODS

Sex and disease differences in total score and ACE subtypes from the ACE Questionnaire in subjects with IBS and control subjects were assessed. Cross-sectional mediation analysis determined if anxiety (Hospital Anxiety and Depression Scale) and resilience (Connor-Davidson Resilience Scale or Brief Resilience Scale) mediated the relationship between ACE and IBS.

RESULTS

Of 798 participants studied, 368 met IBS diagnostic criteria (265 women, 103 men) and 430 were healthy control subjects (277 women, 153 men). Prevalence and number of ACE were higher in IBS versus control subjects (P < .001) but similar between IBS women and men. Household mental illness increased odds of having IBS in women (odds ratio [OR], 1.95; 95% confidence interval [CI], 1.35-2.85; false discovery rate [FDR], 0.002) and men (OR, 2.32; 95% CI, 1.26-4.33; FDR, 0.014). Emotional abuse increased odds of having IBS in women (OR, 1.94; 95% CI, 1.23-3.09; FDR, 0.019) and sexual abuse increased odds of IBS in men (OR, 3.54; 95% CI, 1.35-10.38; FDR, 0.027). Anxiety mediated 54% (P < .001) of ACE's effect on IBS risk and resilience mediated 12%-14% (Connor-Davidson Resilience Scale, P = .008; Brief Resilience Scale, P = .018).

CONCLUSIONS

Both men and women with a history of ACE are twice as likely to have IBS than those without an ACE. Anxiety mediated the relationship between ACE and IBS in men and women and resilience mediated this relationship only in women.

Novel Irritable Bowel Syndrome Subgroups are Reproducible in the Global Adult Population

BACKGROUND & AIMS

Current classification systems for irritable bowel syndrome (IBS) based on bowel habit do not consider psychological impact. We validated a classification model in a UK population with confirmed IBS, using latent class analysis, incorporating psychological factors. We applied this model in the Rome Foundation Global Epidemiological Survey (RFGES), assessing impact of IBS on the individual and the health care system, and examining reproducibility.

METHODS

We applied our model to 2195 individuals in the RFGES with Rome IV-defined IBS. As described previously, we identified 7 clusters, based on gastrointestinal symptom severity and psychological burden. We assessed demographics, health care-seeking, symptom severity, and quality of life in each. We also used the RFGES to derive a new model, examining whether the broader concepts of our original model were replicated, in terms of breakdown and characteristics of identified clusters.

RESULTS

All 7 clusters were identified. Those in clusters with highest psychological burden, and particularly cluster 6 with high overall gastrointestinal symptom severity, were more often female, exhibited higher levels of health care-seeking, were more likely to have undergone previous abdominal surgeries, and had higher symptom severity and lower quality of life (P < .001 for trend for all). When deriving a new model, the best solution consisted of 10 clusters, although at least 2 seemed to be duplicates, and almost all mapped on to the previous clusters.

CONCLUSIONS

Even in the community, our original clusters derived from patients with physician-confirmed IBS identified groups of individuals with significantly higher rates of health care-seeking and abdominal surgery, more severe symptoms, and impairments in quality of life.

Pleasurable and problematic receptive anal intercourse and diseases of the colon, rectum and anus

The ability to experience pleasurable sexual activity is important for human health. Receptive anal intercourse (RAI) is a common, though frequently stigmatized, pleasurable sexual activity. Little is known about how diseases of the colon, rectum, and anus and their treatments affect RAI. Engaging in RAI with gastrointestinal disease can be difficult due to the unpredictability of symptoms and treatment-related toxic effects. Patients might experience sphincter hypertonicity, gastrointestinal symptom-specific anxiety, altered pelvic blood flow from structural disorders, decreased sensation from cancer-directed therapies or body image issues from stoma creation. These can result in problematic RAI - encompassing anodyspareunia (painful RAI), arousal dysfunction, orgasm dysfunction and decreased sexual desire. Therapeutic strategies for problematic RAI in patients living with gastrointestinal diseases and/or treatment-related dysfunction include pelvic floor muscle strengthening and stretching, psychological interventions, and restorative devices. Providing health-care professionals with a framework to discuss pleasurable RAI and diagnose problematic RAI can help improve patient outcomes. Normalizing RAI, affirming pleasure from RAI and acknowledging that the gastrointestinal system is involved in sexual pleasure, sexual function and sexual health will help transform the scientific paradigm of sexual health to one that is more just and equitable.

Gut Microbiota and Gastrointestinal Symptoms in the Global Assessment of Obsessive-Compulsive Disorder: A Narrative Review of Current Evidence and Practical Implications

A growing body of literature suggests a link between bowel syndromes (e.g., irritable bowel syndrome and inflammatory bowel disease), gut microbiome alterations, and psychiatric disorders. This narrative review aims to explore the potential role of the gut microbiome in the pathogenesis and clinical presentation of obsessive-compulsive disorder (OCD) and to explore whether there is sufficient evidence to warrant considering gastrointestinal symptoms and their implication for the gut microbiome during the assessment and treatment of OCD. For this purpose, a PubMed search of studies focusing on OCD, gut microbiota, irritable bowel syndrome, and inflammatory bowel disease was conducted by two independent reviewers. While the current literature on gut microbiome and gastrointestinal issues in OCD remains limited, emerging evidence suggests gut microbiome alterations and high rates of bowel syndromes in this population. These findings emphasize the importance of incorporating comprehensive gastrointestinal assessments into the "global assessment of OCD". Such assessment should encompass various factors, including gastrointestinal physical comorbidities and symptoms, nutritional habits, bowel habits, fluid intake, exercise patterns, and potential microbiome dysfunctions and inflammation. Considering the treatment implications, interventions targeting gut health, such as probiotics and dietary modifications, may hold promise in improving symptoms in OCD patients with comorbid gastrointestinal problems. Further research in this area is warranted to better understand the interplay between gut health and OCD and to explore the effectiveness of targeted interventions in improving clinical outcomes.

Exploration of the mechanism of Traditional Chinese Medicine for anxiety and depression in patients with diarrheal irritable bowel syndrome based on network pharmacology and meta-analysis

Background

The efficacy of Chinese herbal medicine (CHM) in managing irritable bowel syndrome with diarrhea (IBS-D) accompanied by anxiety and depression remains uncertain. Thus, a systematic review was carried out employing meta-analysis and network pharmacology to ascertain the efficacy and underlying mechanisms of CHM therapy.

Methods

By conducting a systematic review, including literature search, screening, and data extraction, we identified 25 randomized controlled trials to assess CHM's effectiveness in treating irritable bowel syndrome alongside anxiety and depression. Network pharmacology was utilized to scrutinize the metabolite utility of CHM in addressing this condition. Potential primary mechanisms were synthesized using information sourced from the PubMed database.

Results

Twenty-five studies, including 2055 patients, were analyzed, revealing significant treatment efficacy for IBS-D in the trial group compared to controls [OR = 4.01, 95% CI (2.99, 5.36), I2 = 0%] Additionally, treatment for depression [SMD = -1.08, 95% CI (-1.30, -0.86), p < 0.00001, I2 = 68%; SDS: SMD = -1.69, 95% CI (-2.48, -0.90), p < 0.0001, I2 = 96%] and anxiety [HAMA: SMD = -1.29, 95% CI (-1.68, -0.91), p < 0.00001, I2 = 89%; SAS: SMD = -1.75, 95% CI (-2.55, -0.95), p < 0.00001, I2 = 96%] significantly improved in the trial group. Furthermore, the trial group exhibited a significantly lower disease relapse rate [OR = 0.30, 95% CI (0.20, 0.44), p < 0.00001, I2 = 0%]. CHM treatment consistently improved IBS severity (IBS-SSS) and symptom scores. Network pharmacology analysis identified key chemical metabolites in traditional Chinese medicine formulations, including Beta-sitosterol, Stigmasterol, Quercetin, Naringenin, Luteolin, Kaempferol, Nobiletin, Wogonin, Formononetin, and Isorhamnetin. Utilizing the STRING database and Cytoscape v3.9.0 software, a protein-protein interaction (PPI) network revealed the top eight key targets: IL-6, TNF, PPARG, PTGS2, ESR1, NOS3, MAPK8, and AKT1, implicated in anti-inflammatory responses, antioxidant stress modulation, and neurotransmitter homeostasis maintenance.

Conclusion

Chinese Herbal Medicine (CHM) offers a promising and safe treatment approach for patients dealing with Diarrheal Irritable Bowel Syndrome (IBS-D) accompanied by anxiety and depression; thus, indicating its potential for practical implementation. The most active metabolites of CHM could simultaneously act on the pathological targets of IBS-D, anxiety, and depression.The diverse scope of CHM's therapeutic role includes various aspects and objectives, underscoring its potential for broad utilization.

Biobehavioral approach to distinguishing panic symptoms from medical illness

Panic disorder is a common psychiatric diagnosis characterized by acute, distressing somatic symptoms that mimic medically-relevant symptoms. As a result, individuals with panic disorder overutilize personal and healthcare resources in an attempt to diagnose and treat physical symptoms that are often medically benign. A biobehavioral perspective on these symptoms is needed that integrates psychological and medical knowledge to avoid costly treatments and prolonged suffering. This narrative review examines six common somatic symptoms of panic attacks (non-cardiac chest pain, palpitations, dyspnea, dizziness, abdominal distress, and paresthesia), identified in the literature as the most severe, prevalent, or critical for differential diagnosis in somatic illness, including long COVID. We review somatic illnesses that are commonly comorbid or produce panic-like symptoms, their relevant risk factors, characteristics that assist in distinguishing them from panic, and treatment approaches that are typical for these conditions. Additionally, this review discusses key factors, including cultural considerations, to assist healthcare professionals in differentiating benign from medically relevant symptoms in panic sufferers.

Factors Associated With the Prevalence of Irritable Bowel Syndrome: The Miyagi Part of the Tohoku Medical Megabank Project Community-based Cohort Study

Background/Aims

The objective of this research is to examine factors related to irritable bowel syndrome (IBS) prevalence in a large population-based study.

Methods

A cross-sectional study was conducted with participants in the Miyagi part of the Tohoku Medical Megabank Project Community-Based cohort study who completed the Rome II Modular Questionnaire. Multivariate odds ratios (ORs) for the presence of IBS and 95% confidence intervals (95% CIs) for the reference group were calculated for each factor. Additionally, a stratified analysis was performed by sex and age group (20-49 years, 50-64 years, and ≥ 65 years).

Results

Among 16 252 participants, 3025 (18.6%) had IBS, comprising 750 men (15.5%) and 2275 women (19.9%). Multivariate ORs for the presence of IBS decreased significantly with each year of age (OR, 0.98; 95% CI, 0.98-0.99). Moreover, compared with the reference group, ORs for the presence of IBS were significantly higher in individuals whose home was partially damaged by the Great East Japan Earthquake, those with < 16 years of education, those who spent less time walking, those with high perceived stress (1.77, 1.57-2.01), those with high psychological distress (1.58, 1.36-1.82), and those with high symptoms of depression (1.76, 1.60-1.94). In stratified analyses, a significant relationship was found between psychological factors and IBS prevalence in all sex and age groups.

Conclusions

This large cross-sectional population-based cohort study identified several factors associated with IBS prevalence. Psychological factors were significantly associated with IBS prevalence across all age groups and sexes.

Efficacy of Shu-yi-ning-chang decoction on IBS-D: Modulating Nr4a3 pathway to reduce visceral hypersensitivity

AIM OF THE STUDY

To evaluate the therapeutic effect of SYNC in diarrhea irritable bowel syndrome (IBS-D) and explore its underlying mechanism through transcriptomic sequencing (RNA-Seq).

MATERIALS AND METHODS

A rat model of IBS-D was constructed to elucidate the effects of SYNC. Abdominal withdrawal reflex (AWR), fecal water content (FWC), and recording body weight were calculated to assess visceral sensitivity in rats. Histopathological changes in the colon and alterations in mast cell (MC) count were determined. Immunohistochemistry was employed to assess mast cell tryptase (MCT) expression in rat colons. Serum levels of corticotropin-releasing Hormone (CRH), interleukin-6 (IL-6), calcitonin gene-related peptide (CGRP), and 5-hydroxytryptamine (5-HT) were quantified using ELISA. RNA-Seq of colon tissue was performed, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Western blot analysis was conducted to quantify the expression levels of key proteins in the Nr4a3 pathway in the colon and hypothalamus tissues of rats.

RESULTS

SYNC alleviated visceral hypersensitivity and mood disorders in rats with IBS-D. Moreover, it was positively correlated with its dosage and the observed effects, such as the enhancement of the colon's mucosal lining condition and reduction in the number and activation of MCs within the model group. SYNC reduced the expression levels of factors related to the brain-gut axis and inflammatory markers in the bloodstream. RNA-Seq analysis indicated that SYNC down-regulated the expression of Nr4a3 and PI3K. These SYNC-targeted genes primarily played roles in immune regulation and inflammatory responses, correlating with the modulation of Nr4a3 and the PI3K/AKT pathway. Western blot analysis further confirmed SYNC's influence on inflammation-related MC activation by downregulating key proteins in the Nr4a3/PI3K pathway.

CONCLUSIONS

SYNC inhibited mast cell activation and attenuated visceral hypersensitivity in the colon tissues of IBS-D rats. These effects were mediated by the Nr4a3/PI3K signaling pathway.

Risk factors for irritable bowel syndrome: A review

Irritable bowel syndrome (IBS) is one of the most common diseases of the digestive tract from the group of disorders of interaction in the gut-brain axis. IBS has a negative impact of on patients' quality of life and the significant social and economic burden of the disease due to the low effectiveness of available treatment strategies, which are only symptomatic, without impacting factors and mechanisms of intestinal dysfunction. From this perspective, it is critical to study the factors contributing to the onset and persistence of IBS symptoms to improve the early diagnosis of the disease and implement targeted prevention technology in at-risk groups. The objective of this paper is to systematize data on the main risk factors for IBS, including hereditary predisposition, stress and psycho-emotional state, diet and eating habits, and acute intestinal infections.

Regulation of the MCHergic Neural Circuit to Dorsal Raphe Nucleus on Emotion-Related Behaviors and Intestinal Dysfunction in Mice Model of Irritable Bowel Syndrome with Diarrhea

INTRODUCTION

Irritable bowel syndrome with diarrhea (IBS-D) is frequently accompanied by depression and anxiety, resulting in a reduced quality of life and increased medical expenditures. Although psychological factors are known to play an important role in the genesis and development of IBS-D, an understanding of the central neural control of intestinal dysfunction remains elusive. Melanin-concentrating hormone (MCH) is a gut-brain peptide involved in regulating feeding, sleep-wake rhythms, and emotional states.

METHODS

This study investigated the regulation of the MCHergic neural circuit from the lateral hypothalamic area (LHA) to the dorsal raphe nucleus (DRN) on anxiety- and depression-like behaviors, intestinal motility, and visceral hypersensitivity in a mice model of IBS-D. The models of IBS-D were prepared by inducing chronic unpredictable mild stress.

RESULTS

Chemogenetic activation of the MCH neurons in the LHA could excite serotonin (5-HT) neurons in the DRN and induce anxiety- and depression-like behaviors and IBS-D-like symptoms, which could be recovered by microinjection of the MCH receptor antagonist SNAP94847 into the DRN. The mice model of IBS-D showed a reduction of 5-HT and brain-derived neurotrophic factor (BDNF) expression in the DRN, while an elevation of 5-HT and BDNF was observed in the colon through immunofluorescent staining, ELISA, and Western blot analysis. SNAP94847 treatment in the DRN alleviated anxiety- and depression-like behaviors, improved intestinal motility, and alleviated visceral hypersensitivity responses by normalizing the 5-HT and BDNF expression in the DRN and colon.

CONCLUSION

This study suggests that the activation of MCH neurons in the LHA may induce IBS-D symptoms via the DRN and that the MCH receptor antagonist could potentially have therapeutic effects.

The role of the gastrointestinal barrier in obesity-associated systemic inflammation

Systemic inflammation is a key contributor to the onset and progression of several obesity-associated diseases and is thought to predominantly arise from the hyperplasia and hypertrophy of white adipose tissue. However, a growing body of works suggests that early changes in the gastrointestinal (GI) barrier may contribute to both local, within the GI lining, and systemic inflammation in obesity. Intestinal barrier dysfunction is well-characterized in inflammatory GI disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) and is known to contribute to systemic inflammation. Thus, drawing parallels between GI disorders, where intestinal permeability and systemic inflammation are prominent features, and obesity-induced GI manifestations may provide insights into the potential role of the intestinal barrier in systemic inflammation in obesity. This review summarizes the current literature surrounding intestinal barrier dysfunction in obesity and explores the potential role of intestinal hyperpermeability and intestinal barrier dysfunction in the development of systemic inflammation and GI dysfunction in obesity.

Major depressive disorder and the risk of irritable bowel syndrome: A Mendelian randomization study

BACKGROUND

The association between major depressive disorder (MDD) and irritable bowel syndrome (IBS) has been found in observational research; however, the causative relationship between MDD and IBS remains uncertain. Using the two-sample Mendelian randomization (MR) approach, we attempted to examine the causal effect of MDD on IBS.

METHODS

Independent genetic variants for MDD identified by Howard et al. based on a genome-wide meta-analysis were selected for this study. Gene-Outcome associations for IBS were gathered from UK Biobank and FinnGen databases. The MR analysis included inverse variance weighted (IVW), MR-Egger regression, weighted median, weighted mode, and MR-PRESSO sensitivity analyses.

RESULTS

FinnGen database subjected to inverse variance weighted (IVW) analysis revealed that MDD may be a risk factor for the development of IBS (OR = 1.356, 95% CI: 1.125-1.632, p = 0.0013). The same finding was reached in UK Biobank for IVW (OR = 1.011, 95% CI: 1.006-1.015, p = 3.18 × 10-7 ), MR-Egger progression (OR = 1.030, 95% CI: 1.008-1.051, p = 0.007), and weighted median (OR = 1.011, 95% CI: 1.005-1.016, p = 0.0001).

CONCLUSION

Our findings supported a causal relationship between MDD and IBS, which may have implications for the clinical management of IBS in individuals with MDD.

Comparing the effectiveness of transdiagnostic treatment with acceptance and commitment therapy on emotional disorders, rumination, and life satisfaction in patients with irritable bowel syndrome: a randomized clinical trial

OBJECTIVE

The present study was conducted to compare the effectiveness of transdiagnostic treatment (UP) with the acceptance and commitment therapy (ACT) on the emotional disorders, rumination, and life satisfaction in the patients with irritable bowel syndrome (IBS).

METHOD

The present study was a randomized clinical trial with a pre-test and post-test design. Between the winter of 2021 and the end of spring 2022, Taleghani Hospital in Tehran received referrals from the statistical population of IBS patients. Of them, 30 individuals (15 in each group) were chosen by convenience sampling and then randomly allocated to groups. UP (It is emotion-based and intervenes in comorbid symptoms), and ACT treatments were provided to the participants online. The participants in the UP and ACT groups received the desired treatments in eight weekly sessions of 45-60 min.

RESULTS

There was no significant difference between UP pre-test and ACT regarding depression, anxiety, rumination, and life satisfaction (P > 0.05). There was no significant difference between UP and ACT post-test in terms of depression, rumination, and life satisfaction (P > 0.05), but due to anxiety, their difference was significant (P < 0.05). Besides, there was a significant difference between pre-test and post-test phases of UP and ACT regarding depression, anxiety, and rumination (P < 0.05). Still, they had no significant difference regarding life satisfaction (P > 0.05).

CONCLUSION

Therefore, it is suggested that specialists use UP and ACT as effective psychological treatments for the emotional symptoms of IBS patients to improve psychological symptoms.

The effect of expectancy versus actual gluten intake on gastrointestinal and extra-intestinal symptoms in non-coeliac gluten sensitivity: a randomised, double-blind, placebo-controlled, international, multicentre study

BACKGROUND

Many individuals without coeliac disease or wheat allergy reduce their gluten intake because they believe that gluten causes their gastrointestinal symptoms. Symptoms could be affected by negative expectancy. Therefore, we aimed to investigate the effects of expectancy versus actual gluten intake on symptoms in people with non-coeliac gluten sensitivity (NCGS).

METHODS

This randomised, double-blind, placebo-controlled, international, multicentre study was done at the University of Leeds (Leeds, UK), Maastricht University (Maastricht, the Netherlands), and Wageningen University and Research (Wageningen, the Netherlands). People aged 18-70 years with self-reported NCGS (ie, gastrointestinal symptoms within 8 h of gluten consumption) without coeliac disease and wheat allergy were recruited. Participants had to follow a gluten-free or gluten-restricted diet for at least 1 week before (and throughout) study participation and had to be asymptomatic or mildly symptomatic (overall gastrointestinal symptom score ≤30 mm on the Visual Analogue Scale [VAS]) while on the diet. Participants were randomly assigned (1:1:1:1; blocks of eight; stratified by site and gender) to one of four groups based on the expectation to consume gluten-containing (E+) or gluten-free (E-) oat bread for breakfast and lunch (two slices each) and actual intake of gluten-containing (G+) or gluten-free (G-) oat bread. Participants, investigators, and those assessing outcomes were masked to the actual gluten assignment, and participants were also masked to the expectancy part of the study. The primary outcome was overall gastrointestinal symptom score on the VAS, which was measured at and corrected for baseline (before breakfast) and hourly for 8 h, with lunch served after 4 h, and analysed per-protocol. Safety analysis included all participants incorporated in the per-protocol analysis. The study is registered at ClinicalTrials.gov, NCT05779358, and has ended.

FINDINGS

Between Oct 19, 2018, and Feb 14, 2022, 165 people were screened and 84 were randomly assigned to E+G+ (n=21), E+G- (n=21), E-G+ (n=20), or E-G- (n=22). One person in the E+G+ group was excluded due to not following test day instructions, leaving 83 participants in the per-protocol analysis. Median age was 27·0 years (IQR 21·0-45·0), 71 (86%) of 83 people were women, and 12 (14%) were men. Mean overall gastrointestinal symptom score was significantly higher for E+G+ (16·6 mm [95% CI 13·1 to 20·0]) than for E-G+ (6·9 mm [3·5 to 10·4]; difference 9·6 mm [95% CI 3·0 to 16·2], p=0·0010) and E-G- (7·4 mm [4·2 to 10·7]; difference 9·1 mm [2·7 to 15·6], p=0·0016), but not for E+G- (11·7 mm [8·3 to 15·1]; difference 4·9 mm [-1·7 to 11·5], p=0·28). There was no difference between E+G- and E-G+ (difference 4·7 mm [-1·8 to 11·3], p=0·33), E+G- and E-G- (difference 4·2 mm [-2·2 to 10·7], p=0·47), and E-G+ and E-G- (difference -0·5 mm [-7·0 to 5·9], p=1·0). Adverse events were reported by two participants in the E+G- group (itching jaw [n=1]; feeling lightheaded and stomach rumbling [n=1]) and one participant in the E-G+ group (vomiting).

INTERPRETATION

The combination of expectancy and actual gluten intake had the largest effect on gastrointestinal symptoms, reflecting a nocebo effect, although an additional effect of gluten cannot be ruled out. Our results necessitate further research into the possible involvement of the gut-brain interaction in NCGS.

FUNDING

Government of the Netherlands Topsector Agri & Food Top Consortium for Knowledge and Innovation, AB Mauri Global Bakery Ingredients, Baking Industry Research Trust, Borgesius-Albert Heijn, CSM Innovation Centre, the International Maize and Wheat Improvement Center (CIMMYT), DSM Food Specialties, Fazer, Healthgrain Forum, the International Association for Cereal Science and Technology, the International Wheat Gluten Association, Lantmännen, Mondelez International, Nederlands Bakkerij Centrum, Nutrition & Santé, Puratos, Rademaker, Sonneveld Group, and Zeelandia HJ Doeleman.

Novel Symptom Subgroups in Individuals With Irritable Bowel Syndrome Predict Disease Impact and Burden

BACKGROUND & AIMS

Current classification systems based on bowel habit fail to capture the multidimensional nature of irritable bowel syndrome (IBS). We previously derived and validated a classification system, using latent class analysis, incorporating factors beyond bowel habit. We applied this in another cohort of people with IBS to assess its ability to capture the impact of IBS on the individual, the health care system, and society.

METHODS

We collected demographic, symptom, and psychological health data from adults in the community self-identifying as having IBS, and meeting Rome IV criteria. We applied our latent class analysis model to identify the 7 subgroups (clusters) described previously, based on overall gastrointestinal symptom severity and psychological burden. We assessed quality of life, health care costs (£1 = $1.20), employment status, annual income, work productivity, and ability to perform work duties in each cluster.

RESULTS

Of 1278 responders, 752 (58.8%) met Rome IV criteria. The 7-cluster model fit the data well. The patients in the 4 clusters with the highest psychological burden, and particularly those in cluster 6 with high overall gastrointestinal symptom severity and high psychological burden, showed lower educational levels, higher gastrointestinal symptom-specific anxiety, were more likely to have consulted a gastroenterologist, and used more drugs for IBS. IBS-related and generic quality of life were impaired significantly in these 4 clusters and significantly fewer individuals reported earning ≥£30,000 per year. Productivity and the ability to work, manage at home, engage in social and private leisure activities, and maintain close relationships all were impacted significantly, and IBS-related health care costs over the previous 12 months were highest in these 4 clusters. In those in cluster 6, costs were more than £1000 per person per year.

CONCLUSIONS

Our clusters identify groups of individuals with significant impairments in quality of life, earning potential, and ability to work and function socially, who are high utilizers of health care.

Overexpression of EphB2 in the basolateral amygdala is crucial for inducing visceral pain sensitization in rats subjected to water avoidance stress

AIMS

Basolateral amygdala (BLA), as a center for stress responses and emotional regulation, is involved in visceral hypersensitivity of irritable bowel syndrome (IBS) induced by stress. In the present study, we aimed to investigate the role of EphB2 receptor (EphB2) in BLA and explore the underlying mechanisms in this process.

METHODS

Visceral hypersensitivity was induced by water avoidance stress (WAS). Elevated plus maze test, forced swimming test, and sucrose preference test were applied to assess anxiety- and depression-like behaviors. Ibotenic acid or lentivirus was used to inactivate BLA in either the induction or maintenance stage of visceral hypersensitivity. The expression of protein was determined by quantitative PCR, immunofluorescence, and western blot.

RESULTS

EphB2 expression was increased in BLA in WAS rats. Inactivation of BLA or downregulation of EphB2 in BLA failed to induce visceral hypersensitivity as well as anxiety-like behaviors. However, during the maintenance stage of visceral pain, visceral hypersensitivity was only partially relieved but anxiety-like behaviors were abolished by inactivation of BLA or downregulation of EphB2 in BLA. Chronic WAS increased the expression of EphB2, N-methyl-D-aspartate receptors (NMDARs), and postsynaptic density protein (PSD95) in BLA. Downregulation of EphB2 in BLA reduced NMDARs and PSD95 expression in WAS rats. However, activation of NMDARs after the knockdown of EphB2 expression still triggered visceral hypersensitivity and anxiety-like behaviors.

CONCLUSIONS

Taken together, the results suggest that EphB2 in BLA plays an essential role in inducing visceral hypersensitivity. In the maintenance stage, the involvement of EphB2 is crucial but not sufficient. The increase in EphB2 induced by WAS may enhance synaptic plasticity in BLA through upregulating NMDARs, which results in IBS-like symptoms. These findings may give insight into the treatment of IBS and related psychological distress.

Clinical trial: A Mediterranean diet is feasible and improves gastrointestinal and psychological symptoms in irritable bowel syndrome

BACKGROUND

Diet is fundamental to the care of irritable bowel syndrome (IBS). However, some approaches are not appropriate for individuals experiencing psychological symptoms.

AIMS

To assess feasibility of a Mediterranean diet in IBS and its impact on gastrointestinal and psychological symptoms.

METHODS

We recruited adults with Rome IV IBS and mild or moderate anxiety and/or depressive symptoms to an unblinded 6-week randomised controlled trial. Patients were randomised to Mediterranean diet counselling or habitual diet. We collected gastrointestinal and psychological symptom data, dietary data and stool samples for metagenomic sequencing.

RESULTS

We randomised 59 individuals (29 Mediterranean diet, 30 control); 48 completed the study. The Mediterranean Diet Adherence Screener score was higher in the Mediterranean diet group than controls at week 6 (7.5 [95% CI: 6.9-8.0] vs. 5.7 [5.2-6.3], p < 0.001), and there was a greater score increase than controls (2.1 [95% CI: 1.3-2.9] vs. 0.5 [95% CI: 0.1-1.0], p = 0.004), demonstrating Mediterranean diet feasibility. There was a greater proportion of gastrointestinal symptom responders in the Mediterranean diet group than controls (24/29, 83% vs. 11/30, 37%, p < 0.001) and depression responders (15/29, 52% vs. 6/30 20%, p = 0.015). There was no difference in FODMAP intake at week 6 (p = 0.51). Gastrointestinal adverse events were similar (p = 0.588). There were no differences in change in microbiome parameters between groups.

CONCLUSIONS

A Mediterranean diet is feasible in IBS and leads to improvement in gastrointestinal and psychological symptoms. Although this study was unblinded, these findings together with the broader benefits of the Mediterranean diet, provide strong impetus for future research in IBS. Australia New Zealand Clinical Trials Registry: ACTRN12620001362987.

Genetic associations and potential mediators between psychiatric disorders and irritable bowel syndrome: a Mendelian randomization study with mediation analysis

Objective

Potential causal associations between psychiatric disorders and irritable bowel syndrome have been demonstrated in observational studies; however, these studies are susceptible to underlying confounding and reverse causation biases. We aimed to assess the causal effects of psychiatric disorders on irritable bowel syndrome (IBS) and the potential mediators from a genetic perspective by conducting a Mendelian randomization (MR) study with mediation analysis.

Method

Genetic instruments associated with psychiatric disorders, potential mediators, and IBS were obtained from large-scale genome-wide association studies (GWAS). Three MR methods - the inverse-variance weighted (IVW) method, MR-Egger method, and weighted median method, were used to investigate causal association estimates. Heterogeneity among different genetic instrumental variables (IVs) was assessed using Q tests. Additionally, the MR-PRESSO and MR-Pleiotropy methods were used to verify horizontal pleiotropy and detect outliers that might bias the results, which were removed from further analysis. Consequently, we used MR mediation analysis to investigate potential mediators in the causal associations between psychiatric disorders and IBS.

Results

MR provided evidence of the causal effects of genetically predicted broad depression, major depressive disorder (MDD), anxiety disorder, post-traumatic stress disorder (PTSD), and schizophrenia on IBS. The results of MR mediation analysis demonstrated that the reduction in acetate levels mediated 12.6% of the effects of broad depression on IBS; insomnia mediated 16.00%, 16.20%, and 27.14% of the effects of broad depression, MDD, and PTSD on IBS, respectively; and the increase in blood β-hydroxybutyrate levels mediated 50.76% of the effects of schizophrenia on IBS.

Conclusion

Our study confirmed the brain-gut axis involvement and potential modulators in the pathophysiology of psychiatric disorder-induced IBS from a genetic perspective, and suggests potential therapeutic targets for the disrupted brain-gut axis.

Association of major depressive disorder and increased risk of irritable bowel syndrome: A population-based cohort study and a two-sample Mendelian randomization study in the UK biobank

OBJECTIVE

To examine the association between depression and the risk of incident irritable bowel syndrome (IBS).

METHODS

We included 98,564 participants free of IBS in the UK biobank. Depression was defined by self-report and Hospital Episode Statistics. The main outcome was incident IBS. Cox proportional hazards regression models and two-sample mendelian randomization were performed to estimate the risk of incident IBS.

RESULTS

Among 98,564 participants, 8770 (8.9 %) participants had a depression diagnosis at baseline. During a median of 12.9-year follow-up, 224 cases of incident IBS were identified in patients with depression (2.0 per 1000 person-years), compared with 1625 cases in reference individuals (1.5 per 1000 person-years). After adjustment, the hazard ratio of incident IBS associated with depression was 1.26 (95 % CI: 1.01-1.41). Sensitivity analysis indicated similar results. The two-sample mendelian randomization based on the inverse variance weighted method provided evidence for the harmful role of depression in an increased risk of IBS with an OR of 1.57 (95 % CI: 1.24-1.99).

LIMITATIONS

Depression was mainly measured by self-report online CIDI-SF in the current study, rather than the gold diagnostic criteria including clinical structured interview, which might lead to potential measurement error. Lifestyle behaviors might change during the long-term follow-up, and time-varying covariates (i.e., smoking and alcohol status) may bias the estimate.

CONCLUSIONS

Depression is associated with an increased risk of incident IBS. Further studies are warranted to confirm the role of depression on incident IBS and elucidate the underlying mechanisms.

Molecular Mechanisms of Reelin in the Enteric Nervous System and the Microbiota-Gut-Brain Axis: Implications for Depression and Antidepressant Therapy

Current pharmacological treatments for depression fail to produce adequate remission in a significant proportion of patients. Increasingly, other systems, such as the microbiome-gut-brain axis, are being looked at as putative novel avenues for depression treatment. Dysbiosis and dysregulation along this axis are highly comorbid with the severity of depression symptoms. The endogenous extracellular matrix protein reelin is present in all intestinal layers as well as in myenteric and submucosal ganglia, and its receptors are also present in the gut. Reelin secretion from subepithelial myofibroblasts regulates cellular migration along the crypt-villus axis in the small intestine and colon. Reelin brain expression is downregulated in mood and psychotic disorders, and reelin injections have fast antidepressant-like effects in animal models of depression. This review seeks to discuss the roles of reelin in the gastrointestinal system and propose a putative role for reelin actions in the microbiota-gut-brain axis in the pathogenesis and treatment of depression, primarily reflecting on alterations in gut epithelial cell renewal and in the clustering of serotonin transporters.

Evaluation of the causal effects of blood metabolites on irritable bowel syndrome: Mendelian randomization

BACKGROUND

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by abdominal pain, discomfort, and changes in bowel habits. The mechanism underlying IBS remains unclear, and little evidence exists for clarifying the causal relationship between blood metabolites and IBS.

METHODS

We conducted a Mendelian randomization (MR) study using two samples. Exposure data for 7824 Europeans were extracted from a genome-wide association study (GWAS) on metabolite levels. The IBS GWAS data from the GWAS database were used for the initial analysis. The primary analysis of causal relationships was conducted using inverse-variance weighting (IVW) with MR-Egger and weighted medians as supplementary analyses. Sensitivity analyses were performed using a combination of the Cochran's Q test, MR-Egger intercept test, Mendelian randomization pleiotropy residual sum and outlier, and leave-one-out analysis. For significant associations, replication and meta-analyses were performed using additional independent IBS case GWAS data released by the FinnGen Consortium R9. To identify the metabolites, score regression, confounding analysis, and reverse MR were performed to further assess the causal relationships between the metabolites.

RESULTS

After rigorous screening, we identified four known metabolites to be associated with IBS (stearate, odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.59-0.92; arginine, OR: 1.36, 95% CI: 1.07-1.74; 1-palmitoylglycerol, OR:1.49, 95% CI: 1.07-2.07; 1-palmitoylglycerophosphoinositol, OR: 0.84, 95% CI: 0.71-0.99).

CONCLUSIONS

MR analysis revealed a causal relationship between the four metabolites and IBS, providing preliminary evidence for the pathogenesis of IBS. Our results provide novel insights into the potential biomarkers of IBS.

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.