A NEW Mendelian randomisation study has revealed compelling genetic evidence that insomnia increases the risk of certain gastrointestinal disorders, particularly gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS). The research provides fresh insight into the biological interplay between poor sleep and digestive health.
Genetic insights into insomnia and gut health
While previous observational studies hinted at a connection between insomnia and gastrointestinal disorders, establishing causality has been challenging due to confounding factors such as stress, diet, or co-existing health conditions. To address this, researchers from China used a two-sample Mendelian randomisation (MR) approach, analysing genome-wide association study (GWAS) data from the Open GWAS database.
The team assessed nine digestive conditions in relation to genetic markers of insomnia. Their forward MR analysis revealed that insomnia significantly increased the risk of GERD (odds ratio [OR] = 1.864, 95% CI: 1.16–2.98, P = 0.009) and IBS (OR = 2.401, 95% CI: 1.06–5.44, P = 0.036). This means that people genetically predisposed to insomnia are nearly twice as likely to develop GERD and over twice as likely to suffer from IBS.
Interestingly, reverse MR analyses suggested a complex bidirectional relationship. Chronic gastritis appeared to have a slight protective effect against insomnia (OR = 0.98, P = 0.027), whereas acute gastritis increased the likelihood of developing sleep difficulties (OR = 1.013, P < 0.001). No significant associations were found with the remaining gastrointestinal conditions under investigation.
Implications for clinical practice
These findings highlight that insomnia may not only be a symptom but also a driver of gastrointestinal disorders. The genetic evidence strengthens the argument for screening and managing sleep disorders as part of digestive health care. For patients with persistent GERD or IBS, clinicians may need to consider underlying sleep problems as a contributing factor.
Overall, this study adds weight to the growing recognition of the gut–brain–sleep connection, suggesting that improving sleep could be an important strategy in reducing gastrointestinal disease risk.
Reference
Yu J et al. The relationship between insomnia and multiple gastrointestinal disorders: a Mendelian randomization study. BMC Gastroenterol. 2025;DOI: 0.1186/s12876-025-04228-9.
