Regular bowel movements are a good sign that everything is going well in your stomach and intestines. Diarrhea or constipation can be caused by a disease such as irritable bowel syndrome – a diagnosis that is often made when other causes are ruled out. So far, however, it has not been adequately clarified what is behind the disturbed peristalsis. According to their own information, an international team has shown for the first time that the frequency of bowel movements and the predisposition to irritable bowel syndrome are hereditary.
As reported by Ferdinando Bonfiglio’s group from the Swedish Karolinska Institute, they looked for connections between genes and bowel movements in 167,875 people from the United Kingdom, the Netherlands, Belgium, Sweden and the USA. In people with both high and low stool frequency, certain changes in the DNA occurred more frequently than in the rest of the population, the authors write. “We identified 14 gene locations that were associated with stool frequency.”
The changes affected molecules whose importance for intestinal motility and communication between the intestine and brain was already known from clinical studies, explained bioinformatician Bonfiglio in a press release. For example, some of the genes examined produce neurotransmitters and hormones that are involved in controlling intestinal peristalsis. However, the locus for the “growth factor” BDNF on chromosome 11 played the greatest role: in addition to motility, it also influences protective functions of the intestine such as the epithelial barrier.
Gene profile shows increased risk of irritable bowel syndrome
Bonfiglio and his colleagues also found evidence of common hereditary factors for stool frequency and irritable bowel syndrome. Using data from the UK Biobank, they concluded that test subjects who, from a genetic point of view, were among the 1 percent with the highest stool frequency, had a five times higher risk of irritable bowel syndrome with diarrhea. This could help determine an increased risk of disease, especially for the variant of irritable bowel syndrome that is associated with diarrhea.