A study by CIC bioGUNE points to vitamin B1 as the genetic key to intestinal rhythm
The study identified DNA changes associated with stool frequency, including a surprising connection to vitamin B1 (thiamine).
Bowel habits are not often a topic of conversation, but they reflect how quickly the intestine moves its contents. When this process is disrupted, problems such as constipation, diarrhoea, or irritable bowel syndrome (IBS) can arise. However, the biological mechanisms that regulate bowel movements are not yet fully understood. A new study, published in Gut, provides genetic clues about intestinal motility and points to the biology of vitamin B1 (thiamine) as an unexpected avenue for future research.
The analysis identified 21 regions of the human genome that influence bowel movement frequency, including 10 not previously described. Several of the genetic signals point to pathways and mechanisms already known for their role in bowel movement, reinforcing the biological soundness of the results. These include the regulation of bile acids, which facilitate fat digestion and act as signalling molecules in the gut, and nerve signalling involved in intestinal muscle contractions, including that related to acetylcholine.
The most notable finding emerged when prioritising two key genes related to vitamin B1 biology, specifically the transport and activation of thiamine in the body (SLC35F3 and XPR1). To assess whether this signal was reflected in real data,
the research team analysed additional dietary information from the UK Biobank. In 98,449 participants, a higher dietary intake of thiamine was associated with a higher frequency of bowel movements. Furthermore, this relationship varied according to each person’s genetic makeup in the SLC35F3 and XPR1 genes, analysed jointly using a combined genetic score. These results suggest that hereditary differences in thiamine metabolism may influence how vitamin B1 intake is related to bowel habits in the general population.
