Genetic dissection of stool frequency implicates vitamin B1 metabolism and other actionable pathways in the modulation of gut motility.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41558814.
- Also identified by DOI 10.1136/gutjnl-2025-337059.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Genetic studies of stool frequency (SF), an indirect proxy for gastrointestinal transit, may reveal therapeutically tractable pathways relevant to IBS and other dysmotility disorders. To identify genes and mechanisms involved in gut motility, providing a foundation for clinical translation. We performed a multiancestry genome-wide association study (GWAS) meta-analysis of SF in 268 606 European and East Asian individuals. Heritability and genetic correlations with other traits were estimated, and Mendelian randomisation was used to test causal relationships. GWAS signals were fine-mapped and functionally annotated to prioritise candidate genes and pathways. Findings implicating thiamine metabolism were followed-up with dietary interaction analyses in UK Biobank (UKB). SF heritability was comparable in Europeans (7.0%) and East Asians (5.6%). We observed strong genetic correlations with gastrointestinal and psychiatric disorders (r<sub>g</sub>=0.18-0.47), and causal effects on IBS. Novel correlations with cardiovascular traits (r<sub>g</sub>=0.12-0.14) were supported by drug signature enrichment analyses. We identified 21 independent loci, including 10 novel signals implicating bile acid synthesis (<i>KLB</i>) and cholinergic signalling (<i>COLQ</i>). Fine-mapping converged on vitamin B1 metabolism, highlighting single-variant causal effects at <i>SLC35F3</i> (a thiamine transporter) and <i>XPR1</i> (phosphate exporter essential for thiamine activation). In 98 449 UKB participants, thiamine intake was positively associated with SF (p<0.0001), and a combined <i>SLC35F3</i>/<i>XPR1</i> genotype score significantly modulated this effect (p<0.0001). We identify therapeutically tractable mechanisms involved in the control of gut motility, including a previously unrecognised role for vitamin B1. These findings warrant mechanistic and clinical studies to evaluate their translational potential in IBS and other dysmotility syndromes.