Meta-analysis identifies genetic links between IBS and psychiatric traits in European ancestry populations

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Frontiers in Medicine Published May 14, 2026 Medically reviewed May 14, 2026 DOI ↗ By Dr. Ji-eun Park, MD · Brain, Mind & Pain

Key Takeaway

Note substantial genetic overlap between IBS and psychiatric traits in European ancestry populations.

This meta-analysis investigates the genetic architecture underlying irritable bowel syndrome, major depressive disorder, and neuroticism. The scope of the review is limited to individuals of European ancestry, as the study population was defined by this ancestry. The analysis synthesizes data to explore genetic correlations and shared genetic mechanisms between these conditions.

The key synthesized findings indicate a substantial genetic overlap between irritable bowel syndrome and psychiatric traits. Specifically, the authors identified up to ten previously unreported IBS loci and uncovered more than 100 pleiotropic loci. These results suggest a complex interplay between gastrointestinal and psychiatric genetic factors.

However, the meta-analysis did not report specific effect sizes, absolute numbers, or p-values for these outcomes. Additionally, details regarding the intervention, comparator, safety, and follow-up duration were not reported. These limitations prevent a definitive assessment of the magnitude of the genetic associations or their direct clinical utility.

Given the absence of reported adverse events and the lack of specific numerical data, the practice relevance is currently unclear. Clinicians should interpret these genetic findings with caution, recognizing that they describe associations rather than established causal mechanisms for treatment decisions.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedMay 2026

View Original Abstract ↓

IntroductionIrritable bowel syndrome (IBS) is a common gut-brain axis disorder characterized by abdominal pain and altered bowel habits, and it shows high comorbidity with psychiatric disorders. However, the shared genetic mechanisms underlying these associations remain incompletely understood.MethodsWe performed a large-scale meta-analysis of IBS in individuals of European ancestry by integrating genome-wide association study (GWAS) summary statistics from the UK Biobank, Bellygenes, and the Million Veteran Program (MVP), thereby increasing statistical power to detect novel IBS loci. We further conducted global genetic correlation analyses with psychiatric traits, followed by multi-trait analysis of GWAS (MTAG) and conditional false discovery rate (condFDR) analyses to identify pleiotropic loci. Transcriptomic, methylomic, and expression quantitative trait locus (eQTL) data were integrated to explore potential regulatory mechanisms.ResultsThe meta-analysis identified up to ten previously unreported IBS loci, several of which were supported by colonic and brain eQTL effects. Global genetic correlation analyses confirmed substantial genetic overlap between IBS and psychiatric traits, particularly major depressive disorder and neuroticism. MTAG and condFDR analyses uncovered more than 100 pleiotropic loci, including signals at SORCS1, SLC35D1, COA1, and TLE1. Integrative analyses of transcriptome- and methylome-wide data highlighted regulatory mechanisms spanning colonic, immune, and neuronal tissues, supporting neuro-immune crosstalk and mitochondrial involvement.DiscussionOur findings provide a comprehensive genetic characterization of IBS, refine its heritable basis, reveal pleiotropic links with psychiatric disorders, and implicate molecular pathways across the gut-brain axis. These results advance mechanistic understanding of IBS and may inform future therapeutic development for IBS and its psychiatric comorbidities.