By Chaima Chihi and يورونيوز Published on November 14, 2026 – 9:27 GMT+1 A scientific study by the University of Copenhagen has found that drinking coffee regularly can affect the functioning of the digestive system, especially bowel movements and colon contractions, and is also linked to a greater diversity of intestinal bacteria. ADVERTISEMENT ADVERTISEMENT The study was published in the journal “Gut Microbiology,” which specializes in research on intestinal microorganisms, and aimed to explore the relationship between habitual coffee consumption and physiological conditions within the digestive system. What does coffee do inside your digestive system? The research team used a small electronic capsule that participants swallowed to track changes that occurred as it traveled through the digestive system. The capsule measured a number of indicators, including the time it took for the contents to pass through the gastrointestinal tract, temperature, acidity levels and intestinal contractions. The study involved 61 healthy adults in Denmark, whom the researchers divided into two groups based on the amount of coffee they consumed. The first group was made up of people who drank between one and five cups of coffee a day for more than three of the eight days covered by the study, while the second group was made up of people who drank coffee less frequently. The results showed that people who regularly consume coffee have a greater diversity of microorganisms present in their intestines compared to participants who drink less coffee. This finding is consistent with research suggesting that coffee can influence the composition of the gut microbiome, the community of bacteria and other microorganisms that live within the digestive system. Francesca Bucci, lead researcher on the study and a doctoral student at the Department of Nutrition, Exercise and Sports at the University of Copenhagen, said regular coffee consumption appears to affect the physiology of the intestines. One of the most notable results was that people who drank coffee regularly had much lower acidity levels in their small intestine than those who consumed it less frequently. The researchers also noted a link between higher coffee intake and a greater number of contractions in the colon, muscle movements that help push intestinal contents through the digestive system. These contractions play a role in digestion and maintaining regularity of bowel movements, as they help move waste and can help prevent constipation and keep intestinal muscles in good condition. Bucci said intestinal contractions can promote proper digestion, help reduce constipation and help maintain the functional state of intestinal muscles. In contrast, researchers cannot yet determine whether a lower level of acidity in the small intestine benefits health or could have negative effects. Is coffee responsible for the changes? The researchers emphasize that the study cannot prove that coffee consumption is the direct cause of the changes observed in the digestive system. However, Henrik Munch Roager, associate professor and head of the research group at the Department of Nutrition, Exercise and Sports at the University of Copenhagen, believes there are reasons to support the possibility that coffee plays a role in these changes. He explained that previous studies have shown that coffee affects a variety of processes that take place within the digestive system, including the secretion of acids in the stomach. He added that this evidence makes it likely that the differences the researchers observed are related to the effects of coffee rather than being a mere coincidence. He noted that many people notice, based on their daily experience, that coffee affects their digestion. The research team sees the next step as conducting a study that controls the amount of coffee the participants drink, instead of just observing their consumption habits and comparing the differences between them. This type of study would help determine if coffee is actually causing these changes and understand the mechanisms through which it may affect bowel movements and contractions.
