A recent study published in the journal Cell Reports Medicine has unveiled significant insights into how the frequency of bowel movements may be intricately linked to long-term health. Conducted by researchers from the Institute for Systems Biology (ISB) in Seattle, the study analyzed data from over 1,400 healthy adults and discovered correlations between bowel movement frequency and signs of decreased organ function.
The study found that individuals who defecate less frequently-defined as one to two times per week-show signs of decreased kidney function. Conversely, those who have bowel movements more frequently-four or more times a day-exhibit signs of impaired liver function. The ideal number of bowel movements, according to the study, is once or twice daily.
"It's well-known that things like constipation are associated with chronic disease," said Sean Gibbons, co-author of the study and an associate professor at ISB. "What is less apparent is which comes first-constipation or chronic disease? Does constipation early in life cause chronic illness, or is it a result of chronic disease?"
Gibbons and his team utilized data from Arivale, a now-defunct wellness company, to explore this question. The participants, primarily white adults from the Pacific Northwest, provided blood and stool samples, as well as responses to questionnaires on diet, exercise, and mental health. The researchers were able to detect chemicals in the blood indicating low organ function and used genetic sequencing of stool samples to analyze the gut microbiome composition.
Participants were categorized into groups based on their bowel movement frequency: one or two per week, three to six per week, one to three per day, and four or more per day. The findings indicated that chronic constipation was linked to decreased kidney function, while frequent diarrhea was associated with impaired liver function.
The gut microbiome, which consists of various microbes that feed on nutrients in stool, plays a crucial role in this dynamic. When stool remains in the gut for extended periods, as in chronic constipation, microbes deplete their fiber supply and turn to proteins, often from the gut's mucus lining. "If we don't feed our microbes, they start eating us," Gibbons explained. This shift leads to the production of toxic metabolites, which can cause inflammation and damage to the kidneys and liver.
Dr. Philipp Hartmann, an assistant professor of pediatric gastroenterology at the University of California, San Diego, who was not involved in the study, noted, "What we can confidently say is gut permeability at least contributes to disease. It may not be the only factor, but it often worsens disease."
In cases of diarrhea, inflammation can degrade the gut's mucosal membrane, allowing toxins to enter the bloodstream and potentially cause organ damage. Joseph Petrosino, chair of molecular virology and microbiology at the Baylor College of Medicine, added, "When you have diarrhea or you have constipation, microbes will accumulate that produce toxins that influence disease."
The study also found that people with regular constipation or diarrhea had more protein-fermenting gut bacteria, whereas those with optimal bowel movement frequency had more fiber-fermenting bacteria. Gibbons suggested that the association between constipation and kidney dysfunction, and diarrhea with liver dysfunction, might relate to bile acid absorption and the metabolites produced by gut microbes.
While the study was not a randomized clinical trial and thus cannot conclusively establish causation, it provides compelling evidence linking bowel movement frequency with chronic disease risk. Gibbons emphasized the importance of maintaining a healthy diet rich in fiber, staying hydrated, and exercising regularly to support optimal bowel movement frequency and overall gut health.
"First and foremost, it's important to eat a healthy diet, feed yourself with foods that fertilize and promote good bacteria growth," advised Petrosino. This includes consuming plenty of fruits and vegetables and reducing intake of alcohol and red meat. For those with chronic digestive issues, probiotics may offer additional support.
