Bowel habits aren’t exactly everyday conversation, but how often we open our bowels reflects how well the gut is working. When gut movement is disrupted, people can experience constipation, diarrhoea, or irritable bowel syndrome (IBS). Despite how common these issues are, the biology controlling gut motility is still not fully understood.
A new large genetics study published in Gut offers fresh insight, identifying DNA differences linked to bowel movement frequency and pointing to vitamin B1 (thiamine) as an unexpected pathway worth further investigation.
👉 Read the study here: https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgaf596/8339900
Using Genetics to Set the Gut’s Pace
The study was led by an international team coordinated by Professor Mauro D’Amato. Researchers analysed genetic and questionnaire data from 268,606 people of European and East Asian ancestry to identify genetic variants associated with how often people open their bowels.
They identified 21 regions of the genome influencing bowel movement frequency, including 10 that had not been reported before. Many of these genetic signals pointed to biological pathways already known to affect gut motility, such as bile acid regulation and nerve signalling that controls intestinal muscle contractions. This helped confirm that the findings fit with established gut biology.
A Stand-Out Finding: Vitamin B1
The most unexpected result came from two genes—SLC35F3 and XPR1—both involved in how the body transports and activates vitamin B1 (thiamine).
To explore this further, researchers analysed dietary data from nearly 100,000 UK Biobank participants. They found that higher thiamine intake was linked to more frequent bowel movements. Importantly, this relationship depended on a person’s genetic makeup at these two genes, suggesting that inherited differences in thiamine handling may influence how diet affects bowel habits.
As lead author Dr Cristian Diaz-Muñoz explained, the genetics helped map out the biological pathways that control gut movement, with vitamin B1 standing out alongside well-known mechanisms.
Implications for IBS and Gut Disorders
The study also showed a biological overlap between bowel movement frequency and IBS, reinforcing the idea that gut motility lies at the core of many common digestive conditions.
Professor D’Amato notes that while gut motility disorders are widespread, their underlying biology is difficult to pin down. These genetic findings, particularly around vitamin B1, provide clear and testable leads for future research, including clinical studies.
Why This Matters
This research doesn’t mean vitamin B1 supplements are a cure for gut problems, but it does reshape how we think about gut health. It highlights the role of genetics, diet, and vitamin metabolism in bowel function and opens new avenues for understanding and treating common gut motility disorders in the future.
