Role of the Gut-Brain Axis in the Shared Genetic Etiology Between Gastrointestinal Tract Diseases and Psychiatric Disorders: A Genome-Wide Pleiotropic Analysis

GWAShug: a comprehensive platform for decoding the shared genetic basis between complex traits based on summary statistics

The shared genetic basis offers very valuable insights into the etiology, diagnosis and therapy of complex traits. However, a comprehensive resource providing shared genetic basis using the accessible summary statistics is currently lacking. It is challenging to analyze the shared genetic basis due to the difficulty in selecting parameters and the complexity of pipeline implementation. To address these issues, we introduce GWAShug, a platform featuring a standardized best-practice pipeline with four trait level methods and three molecular level methods. Based on stringent quality control, the GWAShug resource module includes 539 high-quality GWAS summary statistics for European and East Asian populations, covering 54 945 pairs between a measurement-based and a disease-based trait and 43 902 pairs between two disease-based traits. Users can easily search for shared genetic basis information by trait name, MeSH term and category, and access detailed gene information across different trait pairs. The platform facilitates interactive visualization and analysis of shared genetic basic results, allowing users to explore data dynamically. Results can be conveniently downloaded via FTP links. Additionally, we offer an online analysis module that allows users to analyze their own summary statistics, providing comprehensive tables, figures and interactive visualization and analysis. GWAShug is freely accessible at http://www.gwashug.com.

Causal effect of air pollution on the risk of brain health and potential mediation by gut microbiota

OBJECTIVE

Epidemiologic investigations have examined the correlation between air pollution and neurologic disorders and neuroanatomic structures. Increasing evidence underscores the profound influence of the gut microbiota on brain health. However, the existing evidence is equivocal, and a causal link remains uncertain. This study aimed: to determine if there is a causal connection between four key air pollutants, and 42 neurologic diseases, and 1325 distinct brain structures; and to explore the potential role of the gut microbiota in mediating these associations.

METHODS

Univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) models were deployed to estimate the causal impact of air pollutants (including particulate matter [PM] with aerodynamic diameters <2.5 μm [PM2.5], and <10 μm [PM10]; PM2.5 absorbance; and nitrogen oxides [NOx]) on brain health through various Mendelian randomization methodologies. Lastly, the mediating role of the gut microbiome in the connections between the identified pollutants and neurologic diseases and brain structures was systematically examined.

RESULTS

The potential causal associations of PM2.5, PM2.5 absorbance, PM10, and exposure to NOx, with the risks of intracerebral hemorrhage, hippocampal perivascular spaces, large artery strokes, generalized epilepsy with tonic-clonic seizures, Alzheimer's disease, multiple sclerosis, anorexia nervosa, post-traumatic stress disorder (PTSD), and 420 brain structures, were investigated by UVMR analysis. Following adjustment for air pollutants by MVMR analysis, the genetic correlations between PM10 exposure and PTSD and multiple sclerosis remained significant and robust. Importantly, we observed that phylum Lentisphaerae may mediate the association between PM10 and multiple sclerosis. Additionally, PM2.5 absorbance with a greater risk of reduced thickness in the left anterior transverse temporal gyrus of Heschl and a decreased area in the right sulcus intermedius primus of Jensen, mediated by genus Senegalimassilia and genus Lachnospiraceae UCG010, respectively. Finally, we provided evidence that Clostridium innocuum and genus Ruminococcus2 may partly mediate the causal effect of NOx on altered thickness in the left transverse temporal cortex and area in the right sulcus intermedius primus of Jensen, respectively.

CONCLUSION

This study established a genetic connection between air pollution and brain health, implicating the gut microbiota as a potential mediator in the relationship between air pollution, neurologic disorders, and altered brain structures.

'Whole-Body' Perspectives of Schizophrenia and Related Psychotic Illness: miRNA-143 as an Exemplary Molecule Implicated across Multi-System Dysfunctions

A wide array of biological abnormalities in psychotic illness appear to reflect non-cerebral involvement. This review first outlines the evidence for such a whole-body concept of schizophrenia pathobiology, focusing particularly on cardiovascular disease, metabolic syndrome and diabetes, immunity and inflammation, cancer, and the gut-brain axis. It then considers the roles of miRNAs in general and of miRNA-143 in particular as they relate to the epidemiology, pathobiology, and treatment of schizophrenia. This is followed by notable evidence that miRNA-143 is also implicated in each of these domains of cardiovascular disease, metabolic syndrome and diabetes, immunity and inflammation, cancer, and the gut-brain axis. Thus, miRNA-143 is an exemplar of what may be a class of molecules that play a role across the multiple domains of bodily dysfunction that appear to characterize a whole-body perspective of illness in schizophrenia. Importantly, the existence of such an exemplary molecule across these multiple domains implies a coordinated rather than stochastic basis. One candidate process would be a pleiotropic effect of genetic risk for schizophrenia across the whole body.

A population-based study of familial coaggregation and shared genetic etiology of psychiatric and gastrointestinal disorders

BACKGROUND

It has been proposed that having a psychiatric disorder could increase the risk of developing a gastrointestinal disorder, and vice versa. The role of familial coaggregation and shared genetic loading between psychiatric and gastrointestinal disorders remains unclear.

METHODS

This study used the Taiwan National Health Insurance Research Database; 4,504,612 individuals born 1970-1999 with parental information, 51,664 same-sex twins, and 3,322,959 persons with full-sibling(s) were enrolled. Genotyping was available for 106,796 unrelated participants from the Taiwan Biobank. A logistic regression model was used to examine the associations of individual history, affected relatives, and polygenic risk scores (PRS) for schizophrenia (SCZ), bipolar disorder (BPD), major depressive disorder (MDD), and obsessive-compulsive disorder (OCD), with the risk of peptic ulcer disease (PUD), gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD), and vice versa.

RESULTS

Here we show that parental psychiatric disorders are associated with gastrointestinal disorders. Full-siblings of psychiatric cases have an increased risk of gastrointestinal disorders except for SCZ/BPD and IBD; the magnitude of coaggregation is higher in same-sex twins than in full-siblings. The results of bidirectional analyses mostly remain unchanged. PRS for SCZ, MDD, and OCD are associated with IBS, PUD/GERD/IBS/IBD, and PUD/GERD/IBS, respectively. PRS for PUD, GERD, IBS, and IBD are associated with MDD, BPD/MDD, SCZ/BPD/MDD, and BPD, respectively.

CONCLUSIONS

There is familial coaggregation and shared genetic etiology between psychiatric and gastrointestinal comorbidity. Individuals with psychiatric disorder-affected relatives or with higher genetic risk for psychiatric disorders should be monitored for gastrointestinal disorders, and vice versa.

Investigating the Impact of Nutrition and Oxidative Stress on Attention Deficit Hyperactivity Disorder

Background/Objectives: Attention deficit hyperactivity disorder (ADHD) is the most common childhood-onset neurodevelopmental disorder, characterized by difficulty maintaining attention, impulsivity, and hyperactivity. While the cause of this disorder is still unclear, recent studies have stated that heredity is important in the development of ADHD. This is linked to a few comorbidities, including depression, criminal behavior, and anxiety. Although genetic factors influence ADHD symptoms, there are also non-genetic factors, one of which is oxidative stress (OS), which plays a role in the pathogenesis and symptoms of ADHD. This review aims to explore the role of OS in ADHD and its connection to antioxidant enzyme levels, as well as the gut-brain axis (GBA), focusing on diet and its influence on ADHD symptoms, particularly in adults with comorbid conditions. Methods: The literature search included the main available databases (e.g., Science Direct, PubMed, and Google Scholar). Articles in the English language were taken into consideration and our screening was conducted based on several words such as "ADHD", "oxidative stress", "diet", "gut-brain axis", and "gut microbiota." The review focused on studies examining the link between oxidative stress and ADHD, the role of the gut-brain axis, and the potential impact of dietary interventions. Results: Oxidative stress plays a critical role in the development and manifestation of ADHD symptoms. Studies have shown that individuals with ADHD exhibit reduced levels of key antioxidant enzymes, including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), as well as a diminished total antioxidant status (TOS) compared to healthy controls. Additionally, there is evidence of a close bidirectional interaction between the nervous system and gut microbiota, mediated by the gut-brain axis. This relationship suggests that dietary interventions targeting gut health may influence ADHD symptoms and related comorbidities. Conclusions: Oxidative stress and the gut-brain axis are key factors in the pathogenesis of ADHD, particularly in adults with comorbid conditions. A better understanding of these mechanisms could lead to more targeted treatments, including dietary interventions, to mitigate ADHD symptoms. Further research is required to explore the therapeutic potential of modulating oxidative stress and gut microbiota in the management of ADHD.

Molecular mechanisms of silver nanoparticle-induced neurotoxic injury and new perspectives for its neurotoxicity studies: A critical review

Silver nanoparticles (AgNPs) garnered significant attention and applications in the field of nanotechnology due to their unique physicochemical properties. However, with the increasing exposure of AgNPs in the environment and biological systems, concerns about their potential neurotoxicity have also risen. Recent studies on the neurotoxic effects and mechanisms of AgNPs have often relied on traditional toxicological research methods and perspectives. This reliance has limited the extrapolation of these findings to the human brain environment and hindered a deep understanding of the neurotoxicity of AgNPs. This review first outlines the molecular mechanisms of AgNPs-induced neurotoxic injury from a traditional research perspective, identifying oxidative stress, inflammatory responses, and autophagy disorders as key areas of current research. Related molecular signaling pathways, including the nuclear transcription factor-κB (NF-κB) signaling pathway, the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, and the calcium signaling pathway, have been implicated in the neurotoxic injury process induced by AgNPs. Subsequently, we elucidated the unique advantages of the 3D brain organoids applied to the neurotoxicity study of AgNPs by drawing on relevant studies in the same field. We also emphasize that establishing a standardized 3D brain organoids construction platform is a crucial prerequisite for its widespread application. Furthermore, we suggest that future studies should explore the neurotoxicity mechanisms of AgNPs through the lenses of "adaptive homeostasis" and "structure-activity relationship analysis". In conclusion, the neurotoxicity of AgNPs should be comprehensively evaluated by integrating new research techniques and perspectives, ultimately allowing these nanoparticles to better serve human society.

Genetic interactions and pleiotropy in metabolic diseases: Insights from a comprehensive GWAS analysis

This study offers insights into the genetic and biological connections between nine common metabolic diseases using data from genome-wide association studies. Our goal is to unravel the genetic interactions and biological pathways of these complex diseases, enhancing our understanding of their genetic architecture. We employed a range of advanced analytical techniques to explore the genetic correlations and shared genetic variants of these diseases. These methods include Linked Disequilibrium Score Regression, High-Definition Likelihood (HDL), genetic analysis combining multiplicity and annotation (GPA), two-sample Mendelian randomization analyses, analysis under the multiplicity-complex null hypothesis (PLACO), and Functional mapping and annotation of genetic associations (FUMA). Additionally, Bayesian co-localization analyses were used to examine associations of specific loci across traits. Our study discovered significant genomic correlations and shared loci, indicating complex genetic interactions among these metabolic diseases. We found several shared single nucleotide variants and risk loci, notably highlighting the role of the immune system and endocrine pathways in these diseases. Particularly, rs2476601 and its associated gene PTPN22 appear to play a crucial role in the connection between type 2 diabetes mellitus, hypothyroidism/mucous oedema and hypoglycaemia. These findings enhance our understanding of the genetic underpinnings of these diseases and open new potential avenues for targeted therapeutic and preventive strategies. The results underscore the importance of considering pleiotropic effects in deciphering the genetic architecture of complex diseases, especially metabolic ones.

Multitrait Genetic Analysis Identifies Novel Pleiotropic Loci for Depression and Schizophrenia in East Asians

BACKGROUND AND HYPOTHESIS

While genetic correlations, pleiotropic loci, and shared genetic mechanisms of psychiatric disorders have been extensively studied in European populations, the investigation of these factors in East Asian populations has been relatively limited.

STUDY DESIGN

To identify novel pleiotropic risk loci for depression and schizophrenia (SCZ) in East Asians. We utilized the most comprehensive dataset available for East Asians and quantified the genetic overlap between depression, SCZ, and their related traits via a multitrait genome-wide association study. Global and local genetic correlations were estimated by LDSC and ρ-HESS. Pleiotropic loci were identified by the multitrait analysis of GWAS (MTAG).

STUDY RESULTS

Besides the significant correlation between depression and SCZ, our analysis revealed genetic correlations between depression and obesity-related traits, such as weight, BMI, T2D, and HDL. In SCZ, significant correlations were detected with HDL, heart diseases and use of various medications. Conventional meta-analysis of depression and SCZ identified a novel locus at 1q25.2 in East Asians. Further multitrait analysis of depression, SCZ and related traits identified ten novel pleiotropic loci for depression, and four for SCZ.

CONCLUSIONS

Our findings demonstrate shared genetic underpinnings between depression and SCZ in East Asians, as well as their associated traits, providing novel candidate genes for the identification and prioritization of therapeutic targets specific to this population.

Multi-Omics Integration Analysis Pinpoint Proteins Influencing Brain Structure and Function: Toward Drug Targets and Neuroimaging Biomarkers for Neuropsychiatric Disorders

Integrating protein quantitative trait loci (pQTL) data and summary statistics from genome-wide association studies (GWAS) of brain image-derived phenotypes (IDPs) can benefit in identifying IDP-related proteins. Here, we developed a systematic omics-integration analytic framework by sequentially using proteome-wide association study (PWAS), Mendelian randomization (MR), and colocalization (COLOC) analyses to identify the potentially causal brain and plasma proteins for IDPs, followed by pleiotropy analysis, mediation analysis, and drug exploration analysis to investigate potential mediation pathways of pleiotropic proteins to neuropsychiatric disorders (NDs) as well as candidate drug targets. A total of 201 plasma proteins and 398 brain proteins were significantly associated with IDPs from PWAS analysis. Subsequent MR and COLOC analyses further identified 313 potentially causal IDP-related proteins, which were significantly enriched in neural-related phenotypes, among which 91 were further identified as pleiotropic proteins associated with both IDPs and NDs, including EGFR, TMEM106B, GPT, and HLA-B. Drug prioritization analysis showed that 6.33% of unique pleiotropic proteins had drug targets or interactions with medications for NDs. Nine potential mediation pathways were identified to illustrate the mediating roles of the IDPs in the causal effect of the pleiotropic proteins on NDs, including the indirect effect of TMEM106B on Alzheimer's disease (AD) risk via radial diffusivity (RD) of the posterior limb of the internal capsule (PLIC), with the mediation proportion being 11.18%, and the indirect effect of EGFR on AD through RD of PLIC, RD of splenium of corpus callosum (SCC), and fractional anisotropy (FA) of SCC, with the mediation proportion being 18.99%, 22.79%, and 19.91%, respectively. These findings provide novel insights into pathogenesis, drug targets, and neuroimaging biomarkers of NDs.

Role of inflammatory cytokines and the gut microbiome in vascular dementia: insights from Mendelian randomization analysis

Background

Both inflammatory cytokines and the gut microbiome are susceptibility factors for vascular dementia (VaD). The trends in the overall changes in the dynamics of inflammatory cytokines and in the composition of the gut microbiome are influenced by a variety of factors, making it difficult to fully explain the different effects of both on the different subtypes of VaD. Therefore, this Mendelian randomization (MR) study identified the inflammatory cytokines and gut microbiome members that influence the risk of developing VaD and their causal effects, and investigated whether inflammatory cytokines are gut microbiome mediators affecting VaD.

Methods

We obtained pooled genome-wide association study (GWAS) data for 196 gut microbiota and 41 inflammatory cytokines and used GWAS data for six VaD subtypes, namely, VaD (mixed), VaD (multiple infarctions), VaD (other), VaD (subcortical), VaD (sudden onset), and VaD (undefined). We used the inverse-variance weighted (IVW) method as the primary MR analysis method. We conducted sensitivity analyses and reverse MR analyses to examine reverse causal associations, enhancing the reliability and stability of the conclusions. Finally, we used multivariable MR (MVMR) analysis to assess the direct causal effects of inflammatory cytokines and the gut microbiome on the risk of VaD, and performed mediation MR analysis to explore whether inflammatory factors were potential mediators.

Results

Our two-sample MR study revealed relationships between the risk of six VaD subtypes and inflammatory cytokines and the gut microbiota: 7 inflammatory cytokines and 14 gut microbiota constituents were positively correlated with increased VaD subtype risk, while 2 inflammatory cytokines and 11 gut microbiota constituents were negatively correlated with decreased VaD subtype risk. After Bonferroni correction, interleukin-18 was correlated with an increased risk of VaD (multiple infarctions); macrophage migration inhibitory factor was correlated with an increased risk of VaD (sudden onset); interleukin-4 was correlated with a decreased risk of VaD (other); Ruminiclostridium 6 and Bacillales were positively and negatively correlated with the risk of VaD (undefined), respectively; Negativicutes and Selenomonadales were correlated with a decreased risk of VaD (mixed); and Melainabacteria was correlated with an increased risk of VaD (multiple infarctions). Sensitivity analyses revealed no multilevel effects or heterogeneity and no inverse causality between VaD and inflammatory cytokines or the gut microbiota. The MVMR results further confirmed that the causal effects of Negativicutes, Selenomonadales, and Melainabacteria on VaD remain significant. Mediation MR analysis showed that inflammatory cytokines were not potential mediators.

Conclusion

This study helps us to better understand the pathological mechanisms of VaD and suggests the potential value of targeting increases or decreases in inflammatory cytokines and gut microbiome members for VaD prevention and intervention.

Impacts of microbiota and its metabolites through gut-brain axis on pathophysiology of major depressive disorder

Major depressive disorder (MDD) is characterized by a high rate of recurrence and disability, which seriously affects the quality of life of patients. That's why a deeper understanding of the mechanisms of MDD pathology is an urgent task, and some studies have found that intestinal symptoms accompany people with MDD. The microbiota-gut-brain axis is the bidirectional communication between the gut microbiota and the central nervous system, which was found to have a strong association with the pathogenesis of MDD. Previous studies have focused more on the communication between the gut and the brain through neuroendocrine, neuroimmune and autonomic pathways, and the role of gut microbes and their metabolites in depression is unclear. Metabolites of intestinal microorganisms (e.g., tryptophan, kynurenic acid, indole, and lipopolysaccharide) can participate in the pathogenesis of MDD through immune and inflammatory pathways or by altering the permeability of the gut and blood-brain barrier. In addition, intestinal microbes can communicate with intestinal neurons and glial cells to affect the integrity and function of intestinal nerves. However, the specific role of gut microbes and their metabolites in the pathogenesis of MDD is not well understood. Hence, the present review summarizes how gut microbes and their metabolites are directly or indirectly involved in the pathogenesis of MDD.

Advances in gut-brain organ chips

The brain and gut are sensory organs responsible for sensing, transmitting, integrating, and responding to signals from the internal and external environment. In-depth analysis of brain-gut axis interactions is important for human health and disease prevention. Current research on the brain-gut axis primarily relies on animal models. However, animal models make it difficult to study disease mechanisms due to inherent species differences, and the reproducibility of experiments is poor because of individual animal variations, which leads to a significant limitation of real-time sensory responses. Organ-on-a-chip platforms provide an innovative approach for disease treatment and personalized research by replicating brain and gut ecosystems in vitro. This enables a precise understanding of their biological functions and physiological responses. In this article, we examine the history and most current developments in brain, gut, and gut-brain chips. The importance of these systems for understanding pathophysiology and developing new drugs is emphasized throughout the review. This article also addresses future directions and present issues with the advancement and application of gut-brain-on-a-chip technologies.

Anorexia and bulimia in relation to ulcerative colitis: a Mendelian randomization study

Background

Evidence for anorexia and bulimia in relation to the risk of ulcerative colitis (UC) is limited and inconsistent. The objective of this research was to utilize bi-directional, two-sample Mendelian randomization (MR) analysis to predict the causal association between anorexia nervosa and bulimia nervosa with UC.

Methods

The genome-wide association studies (GWAS) provided data for anorexia and bulimia from the UK Biobank, utilizing single-nucleotide polymorphisms (SNP) as instrumental variables. Additionally, genetic associations with UC were collected from various sources including the FinnGen Biobank, the UK Biobank and the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). The main analytical approach utilized in this study was the inverse-variance-weighted (IVW) method. To evaluate horizontal pleiotropy, the researchers conducted MR-Egger regression and MR-PRESSO global test analyses. Additionally, heterogeneity was assessed using the Cochran's Q test.

Results

This study found a negative association between genetically predicted bulimia (OR = 0.943, 95% CI: 0.893-0.996; p = 0.034) and the risk of UC in the IIBDGC dataset, indicating that individuals with bulimia have approximately a 5.7% lower risk of developing UC. No association was observed in the other two datasets. Conversely, genetically predicted anorexia was not found to be causally associated with UC. In bi-directional Mendelian randomization, UC from the IIBDGC dataset was negatively associated with the risk of anorexia (OR = 0.877, 95% CI: 0.797-0.965; p = 0.007), suggesting that UC patients have approximately a 12.3% lower risk of developing anorexia, but not causally associated with bulimia.

Conclusion

Genetically predicted bulimia may have a negative association with the onset of UC, while genetically predicted anorexia does not show a causal relationship with the development of UC. Conversely, genetically predicted UC may have a negative association with the development of anorexia.

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.

Gut microbiota and postpartum depression: a Mendelian randomization study

Background

Increasing evidence suggests a correlation between intestinal microbiota and the gut-brain axis; however, the causal relationship between gut microbiota and postpartum depression (PPD) remains unclear.

Methods

In this study, a two-sample Mendelian randomization (MR) design was employed to analyze the GWAS data of gut microorganisms from the Mibiogen database and PPD data from the UK biobank. Various statistical methods, including inverse variance weighted, MR-Egger, weighted median, weighted model, and MR-PRESSO, were utilized to investigate the causal relationship between gut microbiota and PPD. Additionally, sensitivity analysis was conducted to assess the robustness of the findings.

Results

Through MR analysis, it was found that phylum Actinobacteria (P=0.014, OR=0.971, 95% CI=0.948-0.994) and genus Holdemanella (P=0.023, OR=0.979, 95% CI=0.961-0.997) have protective effects on PPD, while the other two unknown genera, genus Unknown Ids 2001 (P=0.025, OR=0.972,95% CI=0.947-0.996), and genus Unknown Ids 2755 (P=0.012, OR=0.977, 95% CI=0.959-0.995) also has a protective effect on PPD. The sensitivity analysis results indicate that there is no heterogeneity or horizontal pleiotropy.

Conclusion

This study has identified a causal association between Actinomycetota, Holdemanella, and PDD through MR analysis. These findings offer significant contributions to the development of personalized treatment approaches for PPD, encompassing interventions such as dietary modifications or microbiome interventions.

Single-Cell Sequencing Technology and Its Application in the Study of Central Nervous System Diseases

The mammalian central nervous system consists of a large number of cells, which contain not only different types of neurons, but also a large number of glial cells, such as astrocytes, oligodendrocytes, and microglia. These cells are capable of performing highly refined electrophysiological activities and providing the brain with functions such as nutritional support, information transmission and pathogen defense. The diversity of cell types and individual differences between cells have brought inspiration to the study of the mechanism of central nervous system diseases. In order to explore the role of different cells, a new technology, single-cell sequencing technology has emerged to perform specific analysis of high-throughput cell populations, and has been continuously developed. Single-cell sequencing technology can accurately analyze single-cell expression in mixed-cell populations and collect cells from different spatial locations, time stages and types. By using single-cell sequencing technology to compare gene expression profiles of normal and diseased cells, it is possible to discover cell subsets associated with specific diseases and their associated genes. Therefore, scientists can understand the development process, related functions and disease state of the nervous system from an unprecedented depth. In conclusion, single-cell sequencing technology provides a powerful technology for the discovery of novel therapeutic targets for central nervous system diseases.

Enteric Nervous System Alterations in Inflammatory Bowel Disease: Perspectives and Implications

The enteric nervous system (ENS), consisting of neurons and glial cells, is situated along the gastrointestinal (GI) tract's wall and plays a crucial role in coordinating digestive processes. Recent research suggests that the optimal functioning of the GI system relies on intricate connections between the ENS, the intestinal epithelium, the immune system, the intestinal microbiome, and the central nervous system (CNS). Inflammatory bowel disease (IBD) encompasses a group of chronic inflammatory disorders, such as Crohn's disease (CD) and ulcerative colitis (UC), characterized by recurring inflammation and damage to the GI tract. This review explores emerging research in the dynamic field of IBD and sheds light on the potential role of ENS alterations in both the etiology and management of IBD. Specifically, we delve into IBD-induced enteric glial cell (EGC) activation and its implications for persistent enteric gliosis, elucidating how this activation disrupts GI function through alterations in the gut-brain axis (GBA). Additionally, we examine IBD-associated ENS alterations, focusing on EGC senescence and the acquisition of the senescence-associated secretory phenotype (SASP). We highlight the pivotal role of these changes in persistent GI inflammation and the recurrence of IBD. Finally, we discuss potential therapeutic interventions involving senotherapeutic agents, providing insights into potential avenues for managing IBD by targeting ENS-related mechanisms. This approach might represent a potential alternative to managing IBD and advance treatment of this multifaceted disease.

Genome-wide association analysis reveals potential genetic correlation and causality between circulating inflammatory proteins and amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease, continues to elude complete comprehension of its pathological underpinnings. Recent focus on inflammation in ALS pathogenesis prompts this investigation into the genetic correlation and potential causal relationships between circulating inflammatory proteins and ALS.

METHODS

Genome-wide association study (GWAS) data encompassing 91 circulating inflammatory protein measures from 14,824 individuals of European ancestry, alongside records from 27,205 ALS cases and 110,881 controls, were employed. Assessment of genetic correlation and overlap utilized LD score regression (LDSC), high-definition likelihood (HDL), and genetic analysis integrating pleiotropy and annotation (GPA) methodologies. Identification of shared genetic loci involved pleiotropy analysis, functional mapping and annotation (FUMA), and co-localization analysis. Finally, Mendelian randomization was applied to probe causal relationships between inflammatory proteins and ALS.

RESULTS

Our investigation revealed significant genetic correlation and overlap between ALS and various inflammatory proteins, including C-C motif chemokine 28, Interleukin-18, C-X-C motif chemokine 1, and Leukemia inhibitory factor receptor (LIFR). Pleiotropy analysis uncovered shared variations at specific genetic loci, some of which bore potential harm. Mendelian randomization analysis suggested that alterations in specific inflammatory protein levels, notably LIFR, could impact ALS risk.

CONCLUSIONS

Our findings uncover a genetic correlation between certain circulating inflammatory proteins and ALS, suggesting their possible causal involvement in ALS pathogenesis. Moreover, the identification of LIFR as a crucial protein may yield new insights into ALS pathomechanisms and offer a promising avenue for therapeutic interventions. These discoveries provide novel perspectives for advancing the comprehension of ALS pathophysiology and exploring potential therapeutic avenues.

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.

Global research progress of gut microbiota and epigenetics: bibliometrics and visualized analysis

Background

Gut microbiota is an important factor affecting host health. With the further study of the mechanism of gut microbiota, significant progress has been made in the study of the link between gut microbiota and epigenetics. This study visualizes the body of knowledge and research priorities between the gut microbiota and epigenetics through bibliometrics.

Methods

Publications related to gut microbiota and epigenetics were searched in the Web of Science Core Collection (WoSCC) database. Vosviewer 1.6.17 and CiteSpace 6.1.R2 were used for bibliometric analysis.

Results

WoSCC includes 460 articles from 71 countries. The number of publications on gut microbiota and epigenetics has increased each year since 2011. The USA, PEOPLES R CHINA, and ITALY are at the center of this field of research. The University of California System, Harvard University, and the University of London are the main research institutions. Li, X, Yu, Q, Zhang, S X are the top authors in this research field. We found that current research hotspots and frontiers include short-chain fatty acids (SCFA) play an important role in gut microbiota and epigenetic mechanisms, gut microbiota and epigenetics play an important role in host obesity, diet, and metabolism. Gut microbiota and epigenetics are closely related to colorectal cancer, breast cancer, and inflammatory bowel disease. At the same time, we found that gut microbiota regulates epigenetics through the gut-brain axis and has an impact on psychiatric diseases. Therefore, probiotics can regulate gut microbiota, improve lifestyle, and reduce the occurrence and development of diseases.

Conclusion

This is the first comprehensive and in-depth bibliometric study of trends and developments in the field of gut microbiota and epigenetics research. This study helps to guide the direction of research scholars in their current field of study.

Pharmacogenetics in IBS: update and impact of GWAS studies in drug targets and metabolism

INTRODUCTION

Medications are frequently prescribed for patients with irritable bowel syndrome (IBS) or disorders of gut brain interaction. The level of drug metabolism and modifications in drug targets determine medication efficacy to modify motor or sensory function as well as patient response outcomes.

AREAS COVERED

The literature search included PubMed searches with the terms: pharmacokinetics, pharmacogenomics, epigenetics, clinical trials, irritable bowel syndrome, disorders of gut brain interaction, and genome-wide association studies. The main topics covered in relation to irritable bowel syndrome were precision medicine, pharmacogenomics related to drug metabolism, pharmacogenomics related to mechanistic targets, and epigenetics.

EXPERT OPINION

Pharmacogenomics impacting drug metabolism [CYP 2D6 (cytochrome P450 2D6) or 2C19 (cytochrome P450 2C19)] is the most practical approach to precision medicine in the treatment of IBS. Although there are proof of concept studies that have documented the importance of genetic modification of transmitters or receptors in altering responses to medications in IBS, these principles have rarely been applied in patient response outcomes. Genome-wide association (GWAS) studies have now documented the association of symptoms with genetic variation but not the evaluation of treatment responses. Considerably more research, particularly focused on patient response outcomes and epigenetics, is essential to impact this field in clinical medicine.

Shared genetic architecture and causal relationship between liver and heart disease

This study investigates the relationship and genetic mechanisms of liver and heart diseases, focusing on the liver-heart axis (LHA) as a fundamental biological basis. Through genome-wide association study analysis, we explore shared genes and pathways related to LHA. Shared genetic factors are found in 8 out of 20 pairs, indicating genetic correlations. The analysis reveals 53 loci with pleiotropic effects, including 8 loci exhibiting shared causality across multiple traits. Based on SNP-p level tissue-specific multi-marker analysis of genomic annotation (MAGMA) analysis demonstrates significant enrichment of pleiotropy in liver and heart diseases within different cardiovascular tissues and female reproductive appendages. Gene-specific MAGMA analysis identifies 343 pleiotropic genes associated with various traits; these genes show tissue-specific enrichment primarily in the liver, cardiovascular system, and other tissues. Shared risk loci between immune cells and both liver and cardiovascular diseases are also discovered. Mendelian randomization analyses provide support for causal relationships among the investigated trait pairs.

Shared genetic architecture between autoimmune disorders and B-cell acute lymphoblastic leukemia: insights from large-scale genome-wide cross-trait analysis

BACKGROUND

To study the shared genetic structure between autoimmune diseases and B-cell acute lymphoblastic leukemia (B-ALL) and identify the shared risk loci and genes and genetic mechanisms involved.

METHODS

Based on large-scale genome-wide association study (GWAS) summary-level data sets, we observed genetic overlaps between autoimmune diseases and B-ALL, and cross-trait pleiotropic analysis was performed to detect shared pleiotropic loci and genes. A series of functional annotation and tissue-specific analysis were performed to determine the influence of pleiotropic genes. The heritability enrichment analysis was used to detect crucial immune cells and tissues. Finally, bidirectional Mendelian randomization (MR) methods were utilized to investigate the casual associations.

RESULTS

Our research highlighted shared genetic mechanisms between seven autoimmune disorders and B-ALL. A total of 73 pleiotropic loci were identified at the genome-wide significance level (P < 5 × 10-8), 16 of which had strong evidence of colocalization. We demonstrated that several loci have been previously reported (e.g., 17q21) and discovered some novel loci (e.g., 10p12, 5p13). Further gene-level identified 194 unique pleiotropic genes, for example IKZF1, GATA3, IKZF3, GSDMB, and ORMDL3. Pathway analysis determined the key role of cellular response to cytokine stimulus, B cell activation, and JAK-STAT signaling pathways. SNP-level and gene-level tissue enrichment suggested that crucial role pleiotropic mechanisms involved in the spleen, whole blood, and EBV-transformed lymphocytes. Also, hyprcoloc and stratified LD score regression analyses revealed that B cells at different developmental stages may be involved in mechanisms shared between two different diseases. Finally, two-sample MR analysis determined causal effects of asthma and rheumatoid arthritis on B-ALL.

CONCLUSIONS

Our research proved shared genetic architecture between autoimmune disorders and B-ALL and shed light on the potential mechanism that might involve in.

Shared genetic influences between eating disorders and gastrointestinal disease in a large, population-based sample of adult women and men

BACKGROUND

Some preliminary research suggests higher rates of gastrointestinal disease in individuals with eating disorders (EDs). However, research is limited, and it remains unknown what etiologic factors account for observed associations. This was the first study to examine how EDs and dimensional ED symptoms (e.g. body dissatisfaction, binge eating) are phenotypically and etiologically associated with gastrointestinal disease in a large, population-based twin sample.

METHODS

Adult female (N = 2980) and male (N = 2903) twins from the Michigan State University Twin Registry reported whether they had a lifetime ED (anorexia nervosa, bulimia nervosa, or binge-eating disorder) and completed a measure of dimensional ED symptoms. We coded the presence/absence of lifetime gastrointestinal disease (e.g. inflammatory bowel disease) based on responses to questions regarding chronic illnesses and medications. We first examined whether twins with gastrointestinal disease had higher rates of EDs and ED symptoms, then used correlated factors twin models to investigate genetic and environmental contributions to the overlap between disorders.

RESULTS

Twins with gastrointestinal disease had significantly greater dimensional ED symptoms (β = 0.21, p < 0.001) and odds of a lifetime ED (OR 2.90, p = 0.001), regardless of sex. Shared genetic factors fully accounted for the overlap between disorders, with no significant sex differences in etiologic associations.

CONCLUSIONS

Comorbidity between EDs and gastrointestinal disease may be explained by overlap in genetic influences, potentially including inflammatory genes implicated in both types of disorders. Screening for gastrointestinal disease in people with EDs, and EDs in those with gastrointestinal disease, is warranted.

Analyzing the correlation between gastroesophageal reflux disease and anxiety and depression based on ordered logistic regression

Numerous studies have indicated a connection between psychiatric symptoms, specifically anxiety and depression, and gastroesophageal reflux. However, the precise nature of the link between the severity of gastroesophageal reflux disease and the severity of anxiety and depression remains uncertain. Here, we gathered 24-h pH monitoring data and baseline patient information from a cohort of 518 individuals. Additionally, we evaluated their psychological well-being using the Hospital Anxiety and Depression Scale. The relationship between baseline characteristics and varying degrees of anxiety, depression, and gastroesophageal reflux disease (GERD) was assessed using R software version 4.1.3 and logistic regression models. The findings indicate a statistically significant variation in anxiety levels based on gender, as well as a significant disparity in depression groups when considering age and literacy levels. Kruskal-Wallis test analysis revealed a significant positive correlation between the severity of anxiety and depression and the 24-h pH monitoring results in our patient cohort. As the anxiety and depression levels increased, the rank mean for each examination result also increased. Logistic regression modeling analysis showed that a higher anxiety level was associated with a higher level of GERD. In the presence of mild anxiety, there is a statistically significant association with a higher incidence of GERD with an odds ratio (OR) of 2.64 (95% CI 1.50, 4.64). Similarly, the moderately severe anxiety group also exhibits a causal relationship with an increased GERD incidence, with an OR of 6.84 (95% CI 3.92, 12.17). Additionally, moderate to severe depression is associated with a higher incidence of GERD, with an OR of 2.32 (95% CI 1.23, 4.37). The prevalence of GERD was greater among males compared to females (OR 2.29, 95% CI 1.51-3.49). Additionally, an elevated body mass index (BMI) demonstrated a positive correlation with the susceptibility to GERD (OR 1.07, 95% CI 1.01-1.14). Increasing age may promote the occurrence of GERD in patients. These findings may help to provide a better basis for psychological or pharmacological interventions for GERD patients with psychosomatic symptoms in the future, and provide a reference basis for clinical treatment of the disease.

A leaky gut dysregulates gene networks in the brain associated with immune activation, oxidative stress, and myelination in a mouse model of colitis

The gut and brain are increasingly linked in human disease, with neuropsychiatric conditions classically attributed to the brain showing an involvement of the intestine and inflammatory bowel diseases (IBDs) displaying an ever-expanding list of neurological comorbidities. To identify molecular systems that underpin this gut-brain connection and thus discover therapeutic targets, experimental models of gut dysfunction must be evaluated for brain effects. In the present study, we examine disturbances along the gut-brain axis in a widely used murine model of colitis, the dextran sodium sulfate (DSS) model, using high-throughput transcriptomics and an unbiased network analysis strategy coupled with standard biochemical outcome measures to achieve a comprehensive approach to identify key disease processes in both colon and brain. We examine the reproducibility of colitis induction with this model and its resulting genetic programs during different phases of disease, finding that DSS-induced colitis is largely reproducible with a few site-specific molecular features. We focus on the circulating immune system as the intermediary between the gut and brain, which exhibits an activation of pro-inflammatory innate immunity during colitis. Our unbiased transcriptomics analysis provides supporting evidence for immune activation in the brain during colitis, suggests that myelination may be a process vulnerable to increased intestinal permeability, and identifies a possible role for oxidative stress and brain oxygenation. Overall, we provide a comprehensive evaluation of multiple systems in a prevalent experimental model of intestinal permeability, which will inform future studies using this model and others, assist in the identification of druggable targets in the gut-brain axis, and contribute to our understanding of the concomitance of intestinal and neuropsychiatric dysfunction.

Genetic correlation, shared loci, but no causality between bipolar disorder and inflammatory bowel disease: A genome-wide pleiotropic analysis

BACKGROUND AND AIMS

The comorbidity between bipolar disorder (BD) and inflammatory bowel disease (IBD) has been widely reported in observational studies. However, unclear whether this comorbidity reflects a shared genetic architecture.

METHODS

Leveraging large-scale genome-wide association study (GWAS) summary statistics of BD, IBD and its subtypes, ulcerative colitis (UC) and Crohn's disease (CD), we performed a genome-wide pleiotropic analysis to estimate heritability and genetic correlation, identify pleiotropy loci/genes, and explore the shared biological pathway. Mendelian randomization (MR) studies were subsequently employed to infer whether the potential causal relationship is present.

RESULTS

We found a positive significant genetic correlation between BD and IBD (rg = 0.10, P = 7.00 × 10-4), UC (rg = 0.09, P = 2.90 × 10-3), CD (rg = 0.08, P = 6.10 × 10-3). In cross-trait meta-analysis, a total of 29, 24, and 23 independent SNPs passed the threshold for significant association between BD and IBD, UC, and CD, respectively. We identified five novel pleiotropy genes including ZDHHC2, SCRN1, INPP4B, C1orf123, and BRD3 in both BD and IBD, as well as in its subtypes UC and CD. Pathway enrichment analyses revealed that those pleiotropy genes were mainly enriched in several immune-related signal transduction pathways and cerebral disease-related pathways. MR analyses provided no evidence for a causal relationship between BD and IBD.

CONCLUSION

Our findings corroborated that shared genetic basis and common biological pathways may explain the comorbidity of BD and IBD. These findings further our understanding of shared genetic mechanisms underlying BD and IBD, and potentially provide points of intervention that may allow the development of new therapies for these co-occurrent disorders.

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.

Protein-centric omics integration analysis identifies candidate plasma proteins for multiple autoimmune diseases

It remains challenging to translate the findings from genome-wide association studies (GWAS) of autoimmune diseases (AIDs) into interventional targets, presumably due to the lack of knowledge on how the GWAS risk variants contribute to AIDs. In addition, current immunomodulatory drugs for AIDs are broad in action rather than disease-specific. We performed a comprehensive protein-centric omics integration analysis to identify AIDs-associated plasma proteins through integrating protein quantitative trait loci datasets of plasma protein (1348 proteins and 7213 individuals) and totally ten large-scale GWAS summary statistics of AIDs under a cutting-edge systematic analytic framework. Specifically, we initially screened out the protein-AID associations using proteome-wide association study (PWAS), followed by enrichment analysis to reveal the underlying biological processes and pathways. Then, we performed both Mendelian randomization (MR) and colocalization analyses to further identify protein-AID pairs with putatively causal relationships. We finally prioritized the potential drug targets for AIDs. A total of 174 protein-AID associations were identified by PWAS. AIDs-associated plasma proteins were significantly enriched in immune-related biological process and pathways, such as inflammatory response (P = 3.96 × 10-10). MR analysis further identified 97 protein-AID pairs with potential causal relationships, among which 21 pairs were highly supported by colocalization analysis (PP.H4 > 0.75), 10 of 21 were the newly discovered pairs and not reported in previous GWAS analyses. Further explorations showed that four proteins (TLR3, FCGR2A, IL23R, TCN1) have corresponding drugs, and 17 proteins have druggability. These findings will help us to further understand the biological mechanism of AIDs and highlight the potential of these proteins to develop as therapeutic targets for AIDs.

Genetic and observational associations of lung function with gastrointestinal tract diseases: pleiotropic and mendelian randomization analysis

BACKGROUND

The two-way communications along the gut-lung axis influence the immune function in both gut and lung. However, the shared genetic characteristics of lung function with gastrointestinal tract (GIT) diseases remain to be investigated.

METHODS

We first investigated the genetic correlations between three lung function traits and four GIT diseases. Second, we illustrated the genetic overlap by genome-wide pleiotropic analysis (PLACO) and further pinpointed the relevant tissue and cell types by partitioning heritability. Furthermore, we proposed pleiotropic genes as potential drug targets by drug database mining. Finally, we evaluated the causal relationships by epidemiologic observational study and Mendelian randomization (MR) analysis.

RESULTS

We found lung function and GIT diseases were genetically correlated. We identified 258 pleiotropic loci, which were enriched in gut- and lung-specific regions marked by H3K4me1. Among these, 16 pleiotropic genes were targets of drugs, such as tofacitinib and baricitinib targeting TYK2 for the treatment of ulcer colitis and COVID-19, respectively. We identified a missense variant in TYK2, exhibiting a shared causal effect on FEV1/FVC and inflammatory bowel disease (rs12720356, PPLACO=1.38 × 10- 8). These findings suggested TYK2 as a promising drug target. Although the epidemiologic observational study suggested the protective role of lung function in the development of GIT diseases, no causalities were found by MR analysis.

CONCLUSIONS

Our study suggested the shared genetic characteristics between lung function and GIT diseases. The pleiotropic variants could exert their effects by modulating gene expression marked by histone modifications. Finally, we highlighted the potential of pleiotropic analyses in drug repurposing.

Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis

The gut microbiota (GM) plays a crucial role in human health. The bidirectional interaction between GM and the central nervous system may occur via the microbiota-gut-brain axis, possibly regulating the sleep/wake cycle. Recent reports highlight associations between intestinal dysbiosis and sleep disorders, suggesting that probiotics could ameliorate this condition. However, data are poor and inconsistent. The aim of this quantitative metanalytic study is to assess the GM composition in sleep disturbances and evaluate probiotics' effectiveness for managing sleep disorders. A systematic review was carried out until July 2022 in online databases, limiting the literature research to human studies and English language articles. No significant GM diversity between patients with sleep disturbances versus healthy controls was found, revealed by α-diversity, while β-diversity is missing due to lack of proper reporting. However, probiotics supplementation significantly reduced the self-assessed parameter of sleep quality and disturbances Pittsburgh Sleep Quality Index (PSQI) score compared with the placebo. No difference in the Epworth Sleepiness Scale (ESS) score was found. While available data suggest that GM diversity is not related to sleep disturbances, probiotics administration strongly improves sleep quality as a subjective perception. However, heterogeneity of data reporting in the scientific literature should be considered as a limitation.

Relationship between depression severity and respiratory symptoms in US adults: A national cross-sectional study

OBJECTIVE

The relationship between depression severity and cough, wheeze and exertional dyspnoea is unclear. The aim of this study was to explore this relationship.

METHODS

We used weighted logistic regression analysis and fitted curves to explore the relationship between depression severity and respiratory symptoms. In addition, we examined the relationship between depression and COPD and asthma. Stratified analyses were used to analyse specific populations.

RESULTS

We weighted 10,142 subjects to reflect the entire US population. Using the population without depression as a reference, the risk of cough and asthma in the severely depressed population was 3.32 times (OR 3.324, 95% CI 1.567-7.050) and 2.84 times (OR 2.842, 95% CI 1.521-5.311) higher than that in the population without depressive symptoms, and the risk of asthma and COPD was 2.4 times and 2.6 times (OR 2.410, 95% CI 1.371-4.236; OR 2.566, 95% CI 1.236-4.921). In subgroup analyses, the correlation between depression scores and prevalence of cough and wheeze was corrected for gender level. In addition, smoking status and marital status were interaction factors between depression score and prevalence of cough. The prevalence of exertional dyspnoea by depression score was influenced by CVD.

CONCLUSIONS

Depression severity was associated with respiratory symptoms, asthma, and COPD. Gender corrected the correlation between depression and cough and asthma, and depressive state was an independent risk factor for asthma and COPD. This finding provides new ideas for the management of respiratory symptoms and diseases.

Causal atlas between inflammatory bowel disease and mental disorders: a bi-directional 2-sample Mendelian randomization study

Background

The brain-gut axis link has attracted increasing attention, with observational studies suggesting that the relationship between common mental disorders and inflammatory bowel disease (IBD) may run in both directions. However, so far, it is not clear whether there is causality and in which direction.

Methods

We conducted a bidirectional 2-sample Mendelian randomization study to investigate the relationship between IBD, including Crohn's disease (CD) and ulcerative colitis (UC), and mental disorders, using summary-level GWAS data. The main analysis was the inverse variance weighted method. IBD (including CD and UC), and nine mental disorders were used as both exposures and outcomes.

Results

We found that UC could significantly lead to obsessive-compulsive disorder, attention deficit hyperactivity disorder, and autism spectrum disorder, with odds ratio (OR) of 1.245 (95% confidence intervals [CI]: 1.069-1.450; P=0.008), 1.050 (95%CI: 1.023-1.077; P=2.42×10-4), and 1.041 (95%CI: 1.015-1.068; P=0.002) respectively. In addition, we found that bipolar disorder and schizophrenia could increase the odds of IBD, with OR values of 1.138 (95%CI: 1.084-1.194; P=1.9×10-7), and 1.115 (95%CI: 1.071-1.161; P=1.12×10-7), respectively. Our results also indicate that obsessive-compulsive disorder could lead to IBD, especially for UC, with OR values of 1.091 (95%CI: 1.024-1.162; P=0.009), and 1.124 (95%CI: 1.041-1.214; P=0.004), respectively.

Conclusions

Our findings indicate that the brain-gut axis involves the association between IBD, especially UC, and some mental disorders, which guides the targeted prevention, management, and mechanism exploration of these diseases.

A leaky gut dysregulates gene networks in the brain associated with immune activation, oxidative stress, and myelination in a mouse model of colitis

The gut and brain are increasingly linked in human disease, with neuropsychiatric conditions classically attributed to the brain showing an involvement of the intestine and inflammatory bowel diseases (IBDs) displaying an ever-expanding list of neurological comorbidities. To identify molecular systems that underpin this gut-brain connection and thus discover therapeutic targets, experimental models of gut dysfunction must be evaluated for brain effects. In the present study, we examine disturbances along the gut-brain axis in a widely used murine model of colitis, the dextran sodium sulfate (DSS) model, using high-throughput transcriptomics and an unbiased network analysis strategy coupled with standard biochemical outcome measures to achieve a comprehensive approach to identify key disease processes in both colon and brain. We examine the reproducibility of colitis induction with this model and its resulting genetic programs during different phases of disease, finding that DSS-induced colitis is largely reproducible with a few site-specific molecular features. We focus on the circulating immune system as the intermediary between the gut and brain, which exhibits an activation of pro-inflammatory innate immunity during colitis. Our unbiased transcriptomics analysis provides supporting evidence for immune activation in the brain during colitis, suggests that myelination may be a process vulnerable to increased intestinal permeability, and identifies a possible role for oxidative stress and brain oxygenation. Overall, we provide a comprehensive evaluation of multiple systems in a prevalent experimental model of intestinal permeability, which will inform future studies using this model and others, assist in the identification of druggable targets in the gut-brain axis, and contribute to our understanding of the concomitance of intestinal and neuropsychiatric dysfunction.

Immune System and Brain/Intestinal Barrier Functions in Psychiatric Diseases: Is Sphingosine-1-Phosphate at the Helm?

Over the past few decades, extensive research has shed light on immune alterations and the significance of dysfunctional biological barriers in psychiatric disorders. The leaky gut phenomenon, intimately linked to the integrity of both brain and intestinal barriers, may play a crucial role in the origin of peripheral and central inflammation in these pathologies. Sphingosine-1-phosphate (S1P) is a bioactive lipid that regulates both the immune response and the permeability of biological barriers. Notably, S1P-based drugs, such as fingolimod and ozanimod, have received approval for treating multiple sclerosis, an autoimmune disease of the central nervous system (CNS), and ulcerative colitis, an inflammatory condition of the colon, respectively. Although the precise mechanisms of action are still under investigation, the effectiveness of S1P-based drugs in treating these pathologies sparks a debate on extending their use in psychiatry. This comprehensive review aims to delve into the molecular mechanisms through which S1P modulates the immune system and brain/intestinal barrier functions. Furthermore, it will specifically focus on psychiatric diseases, with the primary objective of uncovering the potential of innovative therapies based on S1P signaling.

Causality between inflammatory bowel disease and the cerebral cortex: insights from Mendelian randomization and integrated bioinformatics analysis

Background

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is a chronic, progressive, and recurrent intestinal condition that poses a significant global health burden. The high prevalence of neuropsychiatric comorbidities in IBD necessitates the development of targeted management strategies.

Methods

Leveraging genetic data from genome-wide association studies and Immunochip genotype analyses of nearly 150,000 individuals, we conducted a two-sample Mendelian randomization study to elucidate the driving force of IBD, UC, and CD on cortical reshaping. Genetic variants mediating the causality were collected to disclose the biological pathways linking intestinal inflammation to brain dysfunction.

Results

Here, 115, 69, and 98 instrumental variables genetically predicted IBD, UC, and CD. We found that CD significantly decreased the surface area of the temporal pole gyrus (β = -0.946 mm2, P = 0.005, false discovery rate-P = 0.085). Additionally, we identified suggestive variations in cortical surface area and thickness induced by exposure across eight functional gyri. The top 10 variant-matched genes were STAT3, FOS, NFKB1, JAK2, STAT4, TYK2, SMAD3, IL12B, MYC, and CCL2, which are interconnected in the interaction network and play a role in inflammatory and immune processes.

Conclusion

We explore the causality between intestinal inflammation and altered cortical morphology. It is likely that neuroinflammation-induced damage, impaired neurological function, and persistent nociceptive input lead to morphological changes in the cerebral cortex, which may trigger neuropsychiatric disorders.

Examining the unmet needs of chronic wound patients with common mental disorders

BACKGROUND

Common mental disorders (CMD) are highly morbid conditions not routinely screened for in chronic wound care. A comorbid psychiatric condition's influence on a patient with chronic wounds' quality of life (QoL) is unknown. This study investigates the implications of CMD on QoL in patients with chronic lower extremity (LE) wounds.

METHODS

This cross-sectional study surveyed patients with chronic LE wounds evaluated in our multidisciplinary clinic between June-July 2022. Surveys included validated physical and social QoL questionnaires, including the Lower Extremity Functional Scale (LEFS), Patient-Reported Outcomes Measurement Information System (PROMIS-3a) Scale v2.0, 12-Item Short-Form (SF-12), and a screening tool for common mental disorders, the Self-Reporting Questionnaire 20 (SRQ-20). Data regarding patient demographics, comorbidities, psychiatric diagnoses, and wound care history were retrospectively collected.

RESULTS

Of the 265 identified patients, 39 (14.7%) had documented psychiatric diagnoses, most often depression or anxiety. The diagnosed cohort had higher median SRQ-20 scores (6, IQR: 6 vs. 3, IQR: 5; P < 0.001) and a higher proportion of positive screens for CMD (30.8% vs. 15.5%; P = 0.020) than non-diagnosed patients. There were no differences in physical or social QoL in patients with and without a psychiatric diagnosis. However, individuals screening positively for CMD experienced significantly more pain (T-score 60.2 vs. 51.4, P = 0.0052) and reduced function (LEFS 26.0 vs. 41.0, P < 0.0000).

CONCLUSION

This study illustrates that patients with chronic LE wounds experience potentially meaningful psychologic distress. Further, symptoms of a CMD (SRQ-20 ≥8), rather than a previous diagnosis, may influence pain and functional outcomes. These findings emphasize the potential relevance of psychological distress in this population and reinforce the need for further investigation of actionable responses to this apparent need.