The frequency of bowel movements appears to have a significant impact on general health in the long term and may even increase the risk of various physical diseases, organ damage, depression and anxiety, among other things.
A new study involving experts from the University of Washington examined how the frequency of bowel movements affects the so-called molecular phenotypes in healthy individuals. The results were published in the English-language journal Cell Reports Medicine.
Almost 4,000 healthy participants examined
The team analyzed data from nearly 4,000 adult participants. The researchers focused on people who were classified as generally healthy and excluded people who suffered from certain diseases or took medication.
Stool frequency analyzed
The participants were divided into four different groups depending on the frequency of bowel movements. There was a constipated group in which the participants only had one to two bowel movements per week. The second group had between three and six bowel movements per week, which was classified by the participants as little to normal.
The third group had a high to normal stool frequency with one to three bowel movements per day. The fourth group suffered from diarrhea, the experts add.
After this categorization, the researchers investigated the relationship between the frequency of bowel movements and various factors such as genetics, blood metabolites and intestinal flora.
Gender and BMI influence stool frequency
The researchers found that age, gender and body mass index (BMI) were significantly associated with the frequency of bowel movements. The study showed that younger people, women and people with a lower body mass index in particular tended to have less frequent bowel movements.
According to experts, the frequency of bowel movements can have a major impact on a person's physiology and health. “Previous research has shown that the frequency of bowel movements can have a major impact on the functioning of the intestinal ecosystem,” reports study author Johannes Johnson-Martinez.
Effects on the intestine
“If the stool remains in the intestine for too long, the microbes consume all available fiber, which they ferment into beneficial short-chain fatty acids. After that, the ecosystem switches to fermentation of proteins, which produces various toxins that can enter the bloodstream,” the doctor adds in a recent press release.
It became clear that the microbial composition of the participants' intestinal flora is generally an indicator of the frequency of bowel movements. The intestinal bacteria that are considered healthy and that ferment fiber seemed to thrive particularly well when bowel movements occurred once or twice a day.
In contrast, bacteria associated with protein fermentation or the upper gastrointestinal tract were more prevalent in people who suffered from constipation or diarrhea, the team adds.
In addition, according to the experts, several blood metabolites, among others, showed significant associations with stool frequency, suggesting possible links between intestinal health and the risk of chronic diseases.
Kidneys suffer from constipation
In particular, microbial byproducts of protein fermentation, which are known to damage the kidneys, were enriched in the blood of participants who reported constipation, the researchers explain.
For example, blood levels of indoxysulfate are significantly increased in cases of constipation and are associated with reduced kidney function. In addition, chronic constipation has been linked to neurodegenerative diseases and the progression of chronic kidney disease, explains study author Dr. Sean Gibbons.
The results show that constipation in particular is associated with blood levels of microbially derived toxins, which are known to cause organ damage even before disease is diagnosed, Gibbons said.
In contrast, in participants with diarrhea, substances associated with liver damage were more detectable, and overall the study provides initial evidence of a causal relationship between the frequency of bowel movements, microbial metabolism in the intestine and organ damage.
The study also suggests that there are links between the frequency of bowel movements and anxiety and depression. Mental health may also depend on the frequency of bowel movements.
Last but not least, it has been shown that irregular stool frequency can be an important risk factor for the development of chronic diseases, explains Dr. Gibbons.
According to the researchers, effective strategies to influence bowel movements could therefore benefit health and well-being. (as)