Bowel Study Reveals Ideal Number of Movements a Day

The number of bowel movements you have in a day may be a significant indicator of how healthy you are.

The frequency of a person’s bowel movements can influence their health due to the impacts of defecating on gut microbiome, according to a new paper in the journal Cell Reports Medicine.

The researchers found that defecating 1 to 2 times a day is a “Goldilocks zone” for health.

“Overall, this study shows how bowel movement frequency can influence all body systems, and how aberrant bowel movement frequency may be an important risk factor in the development of chronic diseases,” study co-author Sean Gibbons, an associate professor at the Institute for Systems Biology (ISB), said in a statement.

In the paper, the researchers describe how they analyzed data from over 1,400 adults regarding lifestyle, medical history and frequency of bowel movements. They found that people fell into four categories when it came to bowel movements: one to two per week (constipation), three to six per week (low-normal), one to three per day (high-normal) and diarrhea.

The researchers discovered that younger people, women, and people with a lower body mass index (BMI) tended to poop less frequently.

“Prior research has shown how bowel movement frequency can have a big impact on gut ecosystem function,” co-author Johannes Johnson-Martinez, also a researcher at ISB, said in the statement.

“Specifically, if stool sticks around too long in the gut, microbes use up all of the available dietary fiber, which they ferment into beneficial short-chain fatty acids. After that, the ecosystem switches to fermentation of proteins, which produces several toxins that can make their way into the bloodstream.”

They also discovered a link between the gut microbiome of the participants and the number of times they pooped with health-associated fiber-fermenting gut bacteria. These bacteria seemed to be present in high numbers in people who were in a Goldilocks zone of having 1 to 2 bowel movements a day. Those with constipation or diarrhea instead tended to have bacteria associated with protein fermentation or the upper gastrointestinal tract.

Additionally, the researchers found correlations between bowel movement frequency and metabolites in the blood, indicating a link between chronic disease risk and defecation frequency. Constipated people had higher levels of p-cresol-sulfate and indoxyl-sulfate, which can damage the kidneys and are made by bacterial fermentation of proteins. People with diarrhea had compounds associated with liver damage.

“Chronic constipation has been associated with neurodegenerative disorders and with chronic kidney disease progression in patients with active disease,” said Dr. Sean Gibbons, ISB associate professor and corresponding author of the paper. “However, it has been unclear whether or not bowel movement abnormalities are early drivers of chronic disease and organ damage, or whether these retrospective associations in sick patients are merely a coincidence.

“Here, in a generally healthy population, we show that constipation, in particular, is associated with blood levels of microbially derived toxins known to cause organ damage, prior to any disease diagnosis,” Gibbons said.

The researchers note that eating plenty of fiber, staying hydrated and exercising regularly helped people stay in the Goldilocks zone.

“These insights could inform strategies for managing bowel movement frequency, even in healthy populations, to optimize health and wellness,” Gibbons said.

Do you have a tip on a science story that Newsweek should be covering? Do you have a question about gut bacteria? Let us know via science@newsweek.com.