The Institute for Systems Biology in Seattle has found that having one or two bowel movements a day is associated with the healthiest gut flora in adults. Researchers analyzed medical data from more than 1,400 healthy adults to determine how bowel habits relate to overall health.
The findings, published in the journal Cell Reports Medicine, show that higher or lower bowel movement frequencies correspond with significant abnormalities in gut flora and metabolism.
Healthy individuals experiencing constipation and slow bowel movements showed elevated blood levels of metabolites that are potentially harmful to the kidneys, including cresol sulfate and indoxyl sulfate. These toxic substances are produced by gut microorganisms when stool remains too long in the intestines.
Conversely, people experiencing diarrhea excrete large amounts of bile acids. The liver normally recycles these acids, which are essential for absorbing dietary fats.
Factors influencing intestinal health
Microbiome expert Sean Gibbons said that eating more fruits and vegetables was the clearest signal observed in the study, along with drinking plenty of water, exercising regularly, and following a plant-based diet. He and his research team examined blood samples, gut microbiota composition, genetics, diet, and lifestyle data from the participants.
Gibbons noted that the results do not mean every person must have exactly two bowel movements per day, as digestion varies among individuals. However, persistent constipation or frequent diarrhea may indicate underlying metabolic changes even in people who appear healthy.
Study limitations and future research
The study observed correlations but did not prove a direct cause-and-effect relationship. Because it was an observational study, researchers could not determine whether altered bowel movement frequency directly affects organ function or if other external factors are involved.
Researchers emphasized that their findings must be verified through intervention studies. It remains unclear whether modifying intestinal habits directly reduces the long-term risk of chronic diseases.
