The positive effect of vitamin B1 on peristalsis and bowel habits

Digestion plays a crucial role in our physical and mental health. Ideally, the bowels should be emptied every day, but constipation and other intestinal disorders such as irritable bowel syndrome (IBS) are very common due to changes in peristalsis, genetic variations, and other factors. According to a large international population study published in BMJ Journals GUT, vitamin B1 has a surprising and positive effect on peristalsis and bowel habits.

Although bowel habits are often considered a taboo topic, they are highly important for mental well-being and overall health. The food we consume must first be broken down with the help of stomach acid, bile acids, and enzymes, after which nutrients are absorbed in the small intestine. It is important that transit through the digestive tract is optimal so that waste products can be eliminated from the body one to two times daily. Throughout this process, peristalsis reflects the gastrointestinal tract’s ability to move food and intestinal contents forward through muscle contractions controlled by the autonomic nervous system. Peristalsis also depends on many factors, including communication within the nervous system via the gut–brain axis (GBA), the immune system, and the gut microbiota.
Changes in peristalsis play a key role in the development of constipation, diarrhea, irritable bowel syndrome, and other common intestinal disorders. In addition, poor digestion may increase the risk of various other conditions, partly due to disrupted interactions within the gut–brain axis.

Established knowledge and new genetic findings related to digestion and peristalsis

It is well known that diet, fluid intake, physical activity, and many medications affect digestion and peristalsis. In the new study, an international team of researchers led by Professor Christian Mauro D’Amato from LUM University conducted a more in-depth investigation into how diet and genetics influence peristalsis and bowel frequency.
Using dietary questionnaires, the researchers analyzed the eating habits of more than 250,000 participants. Advanced computational methods also made it possible to identify how genetic variations are associated with bowel frequency and peristalsis.
The analysis confirmed the importance of bile acids in fat digestion and how neural signaling affects peristalsis through muscle contractions. As a new finding, the analysis also revealed the importance of vitamin B1 and specific genes in relation to peristalsis.

The surprising role of vitamin B1

What surprised the researchers most was that the metabolism of vitamin B1 (thiamine), alongside bile acids and neural signaling, significantly influences peristalsis.
In human tissues, vitamin B1 (thiamine) exists in phosphorylated active forms. The researchers identified two genes (SLC35F and XPR1) that play a key role in how vitamin B1 is transported and activated in the body. They also conducted a more detailed analysis of dietary habits and bowel frequency in nearly 100,000 participants from the UK Biobank. Overall, the study revealed the following:

• Vitamin B1 and genetic variations
  Genetic variations play a crucial role in the ability to phosphorylate and activate vitamin B1, which in turn affects peristalsis and many other functions that require vitamin B1.
• The role of our diet
  A higher intake of vitamin B1 is associated with a lower risk of chronic constipation. It may also be noted that foods rich in vitamin B1, such as whole grains, legumes, nuts, and seeds, contain dietary fiber and magnesium, which also support peristalsis. Based on the study’s findings, the researchers suggest that the treatment of chronic constipation, irritable bowel syndrome, and other intestinal disorders may be improved by placing greater emphasis on diet and vitamin B1. The researchers also point out that genetic variations influence the ability to utilize vitamin B1 and the actual requirement.

Why is vitamin B1 deficiency widespread?

In addition to whole and plant-based foods, vitamin B1 is found in meat, organ meats, fish, and dairy products. However, food refining and unbalanced diets increase the risk of deficiency. The same applies to excessive consumption of sugar, coffee, alcohol, and other stimulants. Diuretic medications, antacids, and oral contraceptives also increase the risk of deficiency. Furthermore, as mentioned, genetic variations may increase the actual need for vitamin B1.

References:

Christian Diaz-Muños et al. Genetic dissection of stool frequency implicates vitamin B1 metabolism and other actionable pathways in the modulation of gut mobility. BMJ Journals, Gut 2026

CIC bioGUNE. A common vitamin could influence bathroom frequency. ScienceDaily 2026