Jan 22, 2026
3 min read
A recent genome-wide study has found DNA "instructions" for intestinal motility, suggesting that genes may influence how the human body absorbs and uses vitamin B1.
As DNA signals gut motility, vitamin B1 may play an unexpected role
- The researchers found 21 genomic regions - 10 of which were previously unknown - that show that intestinal motility and "lazy gut" are other heritable traits.
- Specific genes determine how effectively a person absorbs and activates vitamin B1, which directly affects the frequency of bowel movements.
- This discovery establishes vitamin B1 as a target for new clinical and dietary therapies for the management of IBS and chronic constipation.
Recent genome studies have found DNA "clues" to bowel movements.It suggests that specific genes may affect how the human body absorbs and uses vitamin B1 (thiamine), which affects the regularity of bowel movements.
Research shows that vitamin B1 plays this role along with known important functions such as bile acids and nerve signaling.The study analyzed a large data set to identify the genes most associated with stool frequency.Nutrition Insight examines the results with lead study author Mauro D'Amato, professor of medical genetics at LUM University in Italy.
"What surprised us the most was that we were able to identify key biological mechanisms with such a simple approach – combining genetics with people's bowel habits – uncovering both known (bile acids and acetylcholine) and completely new pathways (vitamin B1)," he tells us.
"The new finding was that intestinal motility is a partially inherited trait, meaning that people may be genetically predisposed to 'lazy guts' and, importantly, that the biology of vitamin B1 may be important in controlling peristalsis."
Peristalsis is the involuntary contraction of circular muscles, such as in the digestive tract.Therefore, D'Amato suggests that the results of the study may benefit irritable bowel syndrome (IBS) patients with constipation.
Analysis of genomic data
The researchers learned the burdens and genetic data of 268,606 people of European and East Asia origin, using computational analyzes to determine the genes and mechanisms that are most likely to be involved.
Their analysis identifies 21 regions of the human genome that influence the frequency of bowel movements, including 10 that have not been previously reported.
A number of genetic signals have revealed pathways and mechanisms that influence bowel movements, which the researchers say is good because it means the findings are consistent with established biology.
For example, this research is looking at the regulation of bile acids, where bile acids help digest fats and act as signaling molecules in the gut.Another common influence is the nerve signal that causes contraction of the abdominal muscles.This includes signals related to acetylcholine, which helps nerves communicate with muscles.
Specific genes related to vitamin B1 biology
According to the study authors, the “most striking” results came after they narrowed the findings down to two genes (SLC35F3 and XPR1) that impact how the human body uses vitamin B1 – specifically, how vitamin B1 is transported and activated.
According to the researchers, the results may indicate a meaningful biological correlation between the frequency of bowel movements and pounds, which affects millions of people worldwide.
The relationship between thiamine intake and bowel movement frequency differed depending on a person's genetic makeup of the SLC35F3 and XPR1 genes, which the researchers analyzed together as a combined "genetic score." "We found that these two genes are involved in the absorption and activation of vitamin B1," says D'Amato."This suggests that the vitamin B1 we consume may be more effective in some people than others due to their respective genetic profiles."
To find out whether this vitamin B1 signal was reflected in the real data, the researchers further examined dietary data from 98,449 participants in the UK Biobank.This showed that higher dietary thiamine intake was associated with more frequent bowel activity.
New solutions for IBS
The researchers believe their findings may point to a significant biological overlap between bowel movement frequency and IBS, which affects millions of people worldwide.
"Problems with gut motility are at the heart of IBS, constipation and other common disorders, but the underlying biology is very difficult to pin down," says D'Amato."These genetic findings highlight specific pathways, particularly vitamin B1, as testable leads for the next level of research, including laboratory experiments and carefully designed clinical studies."
"We can expect this to lead to experiments in animal models such as rats treated with vitamin B1, or to well-designed clinical trials to test whether vitamin B1 supplementation affects gut motility by controlling or changing diet."
In another recent breakthrough in nutrition for IBS, researchers at the University of Gothenburg in Sweden have unraveled the complex interactions between gut bacteria and IBS.In a paper published in Cell Reports, they revealed how gut bacteria can produce serotonin, a neurotransmitter known as the "happy hormone" that is crucial for overall digestive health and mood.
Meanwhile, BiOkuris' symbiotic BK002 has shown clinical benefits on gastrointestinal symptoms and a "significant" reduction in anxiety.Nutrition Insight spoke with the company to learn more about why symbiotics are considered superior in treating irritable bowel syndrome.
