Regular coffee consumption may influence how the digestive system works, with people who drink it frequently showing more colon contractions and greater diversity in gut bacteria, according to a study by researchers at the University of Copenhagen.
Published in the journal Gut Microbiology, the research examined how habitual coffee drinking relates to conditions inside the digestive tract. The team used a small electronic capsule, swallowed by participants, to monitor changes as it travelled through the gastrointestinal system.
The capsule recorded several measurements, including the time taken for material to pass through the digestive tract, temperature, acidity and intestinal contractions.
The study involved 61 healthy adults in Denmark, divided into two groups according to their coffee consumption. Regular drinkers were defined as those who consumed between one and five cups a day on more than three of the eight days covered by the research. The second group drank coffee less frequently.
Researchers found that regular coffee drinkers had greater diversity in their gut microorganisms than those who consumed it less often. The finding adds to previous research suggesting that coffee may influence the gut microbiome, the community of bacteria and other microorganisms living in the digestive system.
Another notable difference was lower acidity levels in the small intestine among regular coffee drinkers. The researchers said they could not yet determine whether this change was beneficial or potentially harmful to health.
The team also observed more contractions in the colon among people with higher coffee consumption. These muscular movements help push material through the large intestine and support regular bowel movements.
Francesca Bucci, the study’s lead researcher and a PhD student in the University of Copenhagen’s Department of Nutrition, Exercise and Sports, said the findings indicated that regular coffee consumption appeared to affect intestinal physiology.
She explained that colon contractions help move waste through the digestive system, support bowel regularity and may reduce the risk of constipation. They also help maintain the normal function of intestinal muscles.
However, the researchers stressed that the study does not establish that coffee directly causes these changes. Its observational design allowed them to identify differences between participants with different drinking habits, but not determine whether coffee was responsible.
Henrik Munch Roager, an associate professor who heads the university’s research group in nutrition, exercise and sports, said earlier studies had already shown that coffee could affect digestive processes, including the secretion of stomach acids. He said this provided reasons to believe that coffee may have contributed to the differences observed in the latest research.
The researchers said the next step would be a controlled study in which participants are assigned specific amounts of coffee to drink. This would help establish whether coffee causes the changes and clarify how it affects intestinal activity and the gut microbiome.
