Frequency of Bowel Movements May Be Linked to Long-Term Health: Study

Researchers found that one to two daily bowel movements are linked to beneficial gut bacteria.

Bifidobacteria are vital to gut immunity. Kateryna Kon/Shutterstock

Irregular bowel schedules, particularly constipation and diarrhea, are so common that people often see them as mere annoyances. However, a new study suggests they may increase the risk of chronic diseases.

“We suggest that chronic constipation or diarrhea may be under-appreciated drivers of organ damage and chronic disease, even in healthy populations,” the researchers wrote in the study, published on July 16 in Cell Reports Medicine.

The authors found that people who have less than one bowel movement a day have higher levels of uremic toxins, which are related to chronic kidney diseases, inflammation, and oxidative stress. Meanwhile, having one to two bowel movements daily was linked to more beneficial bacteria. They also found that those who frequently have diarrhea have elevated markers of inflammation and bilirubin, which can indicate liver damage.

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An abundance of literature links abnormal bowel frequency to conditions such as Parkinson’s and chronic kidney disease. However, the new study suggests causal links between gut health and chronic disease. “It’s less known whether these abnormalities are causally influencing the development of chronic disease or are simply a coincidence,” Seattle-based Institute for Systems Biology associate professor Sean Gibbons, one of the study’s authors, told The Epoch Times.

The researchers used a comprehensive set of biological, health, diet, and lifestyle data from 1,425 healthy participants from the defunct scientific wellness company Arivale to study the associations between bowel movement frequency and factors such as gut microbiome composition and blood proteins in healthy individuals.

Constipation and Diarrhea Affect Gut Health

Constipation affects the gut ecosystem and is linked to chronic diseases.

“The gut ecosystem largely focuses on fermenting dietary fiber. That’s sort of the main function of the microbiome; it takes fibers and ferments them into organic [fatty] acids,” Mr. Gibbons said.

Mr. Gibbons noted that if stool stays too long in the gut, microbes exhaust the dietary fibers and start consuming proteins from the mucus layer. This shift to consuming proteins ends up producing a lot of toxins known to damage our organs, he explained. One such toxin often produced in constipation is indoxyl sulfate (3-IS), which is linked to poorer kidney function. This gut imbalance results in fewer organic fatty acids being produced from dietary fibers, contributing to poor health and chronic disease progression.

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“When we looked at people with diarrhea, we saw that markers of liver dysfunction and inflammation were higher,” Mr. Gibbons said.

A healthy gut microbiome prevents inflammation and colonization from pathogens, but diarrhea disrupts the microbiome, driving up inflammation. Mr. Gibbons postulates that diarrhea may also harm the liver, as the rapid movement of stool prevents the reabsorption of bile acids, which the liver produces to digest dietary fats.

This loss burdens the liver to produce more bile acids, contributing to liver dysfunction.

Bacteria Abundance Linked to Bowel Movements

The researchers explored how bowel movement frequency (BMF) variations affect different molecules in the body, organ function, and disease.

Participants’ BMF was categorized into four groups: constipation (passing stool once or twice a week), low-normal (three to six times a week), high-normal (one to three times a day), and diarrhea (four times a day).

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The researchers found that specific gut bacteria are more or less abundant depending on how often people have bowel movements. For instance, beneficial bacteria associated with dietary fiber fermentation were more abundant in those with one to two bowel movements a day. In contrast, people who regularly suffered from constipation and diarrhea had more potentially pathological bacteria in their upper gastrointestinal tract.

Bowel Movements Linked to Diet, Lifestyle, and Mental State

The researchers also looked at potential associations between BMF and demographic factors such as age, sex, body mass index (BMI), and mental state. Results showed the following:

• Higher snack intake was linked to low-normal BMF.
• Higher intake of fruits and vegetables, easier bowel movements, and more frequent diarrhea were linked to high-normal BMF.
• Individuals with lower low-density lipoprotein (better cholesterol) reported eating more fruit.
• Those with lower C-reactive protein (less inflammation) reported eating more vegetables.

The study also found that people with siblings or family members with a history of depression or anxiety experienced abnormal bowel frequency. Similarly, individuals with a personal history of depression or anxiety disorders were associated with low-normal BMF.

These findings align with recent research showing that constipation is linked to an increased risk of depression and anxiety.

Lifestyle Changes to Improve Gut Health

The study emphasized that “common-sense dietary and lifestyle changes, like increasing intake of fruits and vegetables, may help normalize BMF and perhaps reduce BMF-associated risk.”

Mr. Gibbons illustrated that the microbes in the gut act like an engine, transforming what we consume into the body’s biomass. However, this engine doesn’t burn clean and produces toxic byproducts. “Our body is designed to deal with the toxicity, but if it overwhelms our mechanisms for dealing with it, then it causes damage.”

Fortunately, people may be able to improve their bowel movement frequency through diet.

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Mr. Gibbons said that feeding the microbes with a lot of fiber can help correct the physiological processes associated with increased disease risk.” Taking prebiotics and probiotics, including fermented foods like yogurt, sauerkraut, and kimchi, are also good sources of probiotics.

He also recommended a whole-food diet rich in various plants, fruits, and vegetables while avoiding a high-protein diet. “It’s pretty well accepted in the nutrition field that really-high-protein diets are actually very damaging to the body,” he said. For those on a high-protein diet, he suggested supplementing with complex carbs and fibers.

The study had a broad range for what is considered normal, with the low-normal range spanning from passing stool every other day to nearly every day. When The Epoch Times asked about an ideal bowel schedule, Mr. Gibbons suggested that pooping every other day to two to three times a day is a good range. Interestingly, the researchers noted in a statement that fiber-fermenting gut bacteria often linked with health seemed to thrive in a “Goldilocks zone” of BMF, in which people had a bowel movement once or twice daily.

Currently, people—and perhaps even clinicians—do not view bowel movement abnormalities as a cause for concern. “I think our work is showing that it actually perhaps is an important component of what needs to be managed in our health care,” Mr. Gibbons said.