A recent study published in Cell Reports Medicine highlights the significant impact of bowel movement frequency on physiology and long-term health.
Previous studies have linked constipation and diarrhea with higher risks of infections and neurodegenerative conditions, but it was unclear if irregular bowel movements were a cause or result of these conditions.
The research team analyzed clinical, lifestyle, and biological data from over 1,400 healthy adults. Participants self-reported their bowel movement frequencies, which were categorized into four groups: constipation (one or two per week), low-normal (three to six per week), high-normal (one to three per day), and diarrhea.
With prolonged retention of the stool in the gut, microbes exhaust the available fiber—which they ferment into beneficial short-chain fatty acids—and start to ferment proteins, producing toxins like p-cresol sulfate and indoxyl sulfate, which in turn are particularly more toxic to the kidneys.
In cases of diarrhea, clinical indicators of inflammation and liver damage were observed. Diarrhea causes the body to expel excessive bile acid, which the liver would otherwise recycle to absorb dietary fats.
With this in mind, the investigators found that the best health outcomes is linked to passing stools once or twice per day
The study found that younger individuals, women, and those with a lower body mass index tended to have less frequent bowel movements. Hormonal and neurological differences, as well as higher food intake in men, may explain this gap.
Further analysis using biological data and pairing it with lifestyle questionnaires, the researchers found that the healthy bowel movement frequency of 1-2 times per day was associated with higher consumption of fruits and vegetables, adequate hydration, regular physical activity, and a plant-dominant diet.
It is important to remember that stool and the gut are not inert and that prolonged retention of stool lead to significant health issues. One should be having 1 to 2 bowel moments a day at the least, as long as it’s not diarrhea.
And how does one achieve the healthy bowel movement frequency, with standard healthy lifestyle habits of a whole food, plant-based diet, drinking plenty of water, and getting plenty of exercise and physical activity.
JP Johnson-Martinez et al. Aberrant bowel movement frequencies coincide with increased microbe-derived blood metabolites associated with reduced organ function. Cell Reports Medicine (2024). https://doi.org/10.1016/j.xcrm.2024.101646
