Everyone poops from time to time, but does it really matter how often?
A new study published in Cell Reports Medicine reveals that bowel movement frequency significantly influences long-term physiology and health, with the best outcomes associated with having a bowel movement once or twice a day.
Previous research has suggested associations between constipation and diarrhea with higher risks of infections and neurodegenerative diseases, respectively.
But because these results were seen in sick patients, it was unclear whether irregular bathroom visits were the cause or the result of their condition.
“I hope this work opens clinicians’ minds a little bit to the potential risks of not managing bowel movement frequency,” Sean Gibbons, lead author of the study at the Institute for Systems Biology, told AFP, explaining that doctors often dismiss irregular movements as just a “nuisance.”
Gibbons and his team collected clinical, biological and lifestyle data, including blood chemistry, gut microbiome, genetics and more, from more than 1,400 healthy adult volunteers with no signs of active disease.
Participants’ self-reported stool frequencies were categorized into four groups: constipation (one or two stools per week), low-normal (three to six per week), high-normal (one to three per day), and diarrhea.
When stool sits in the gut too long, microbes deplete available fiber—which they ferment into beneficial short-chain fatty acids—and ferment protein instead, producing toxins like p-cresol sulfate and indoxyl sulfate.
“We found that even in healthy people who are constipated, there is an increase in these toxins in the bloodstream,” Gibbons said, noting that these toxins are particularly hard on the kidneys.
In cases of diarrhea, the team found clinical findings that indicated liver inflammation and damage. Gibbons explained that during diarrhea, the body excretes excess bile acid, which the liver would otherwise recycle to dissolve and absorb dietary fats.
Fiber-fermenting gut bacteria, known as “strict anaerobes,” which are associated with good health, thrived in the “Goldilocks zone” of one to two bowel movements per day. However, Gibbons stressed that more research is needed to more precisely define this optimal range.
Demographically, younger people, women, and people with a lower body mass index tended to have less frequent bowel movements.
Hormonal and neurological differences between men and women may explain this discrepancy, Gibbons said, as well as the fact that men generally consume more food.
Finally, by combining biological data with lifestyle questionnaires, the team built a clear picture of who typically falls into the Goldilocks zone.
“Eating more fruits and vegetables was the most important signal we saw,” Gibbons said, along with drinking plenty of water, getting regular exercise and eating a more plant-based diet.
The next step in the research could be to design a clinical trial to manage bowel movements in a large group of people, followed over an extended period, to assess its potential in preventing disease.
© 2024 AFP