How Often You Poop May Influence Your Gut Health and Risk of Chronic Disease

The frequency of bowel movements may have implications beyond just feeling bloated. A recent study suggests it could affect your gut microbiome and the risk of chronic disease.

Published in the journal Cell Reports Medicine, the study found that gut bacteria involved in fiber digestion thrived in individuals who had bowel movements once or twice a day. Conversely, bacteria associated with the upper gastrointestinal tract or protein fermentation were more common in those with diarrhea or constipation, respectively.

The study also observed that younger people, women, and participants with a lower body mass index had less frequent bowel movements.

“Many people with chronic diseases, including Parkinson’s and chronic kidney disease, report having had constipation for years prior to the diagnosis,” noted Dr. Sean Gibbons, the study’s senior author and an associate professor at the Institute for Systems Biology in Seattle. “However, it is unclear whether these bowel movement frequency aberrations are drivers of disease or simply a consequence of disease.”

This uncertainty motivated the researchers to explore the connections between bowel movement frequency, genetics, the gut microbiome, blood plasma chemistries, and blood metabolites. They aimed to determine if bowel movement patterns could negatively affect the body before disease diagnosis.

The study analyzed health and lifestyle data from over 1,400 healthy adults who participated in a scientific wellness program at Arivale, a consumer health company in Seattle. Participants, predominantly White, provided blood and stool samples and answered questionnaires about their bowel habits.

Self-reported bowel movement frequency was categorized into four groups: constipation (one or two bowel movements per week), low-normal (three to six weekly), high-normal (one to three daily), and diarrhea.

The study revealed links between different bowel movement frequencies and various blood metabolites and plasma chemistries. For instance, protein fermentation byproducts like p-Cresol-sulfate and indoxyl sulfate, which can cause kidney damage, were found in higher levels in constipated participants. Additionally, chemistries associated with liver damage and increased inflammation were more prevalent in people with diarrhea.

The authors believe these findings provide preliminary support for a causal link between bowel movement frequency, gut microbial metabolism, and organ damage.

“This study offers a potential pathway for future research to investigate the connection between constipation and chronic kidney disease over time,” said Dr. Kyle Staller, director of the Gastrointestinal Motility Laboratory at Massachusetts General Hospital and an associate professor at Harvard Medical School.

However, there are significant limitations to the study. It does not establish a cause-and-effect relationship, and the data comes from participants studied at a single point in time. Additionally, bowel movement frequency may not be the best measure of bowel function, as stool consistency could be a more accurate indicator.

Many findings are based on participants with normal bowel movement frequency, with fewer insights from those who were constipated or had diarrhea. Furthermore, the technology used to detect bacterial species in stool samples identified only the genus, not specific species, which could have different effects.

Lifestyle factors also played a role, with participants with normal bowel movements tending to consume more fruits and vegetables, stay better hydrated, and exercise more.

Despite these limitations, the study underscores the impact of dietary factors on gut function and highlights the complex interactions between gut bacteria and bodily functions. While it is too early to make sweeping changes based on this study, it contributes to the growing understanding of gut health.

“Any attempt to simplify this knowledge into cultivating the ‘ideal’ gut microbiome is a ways off,” Staller concluded. “Our knowledge in this field is just too underdeveloped to make sweeping changes to our lives based on the findings of a study like this just yet.”