New coffee discovery as study links drink to two physical changes

New coffee discovery as study links drink to two physical changes The study's main discovery is that regular coffee consumption is linked to measurable physical changes For many people, a cup of coffee in the morning can prompt a bathroom visit, but this doesn’t happen to everyone. Research suggests coffee encourages bowel movements in roughly one-third to two-thirds of people. Its effect can depend on how quickly your gut moves, how sensitive you are to caffeine, and whether you drink it with food, which can activate the body’s natural digestive reflexes. Now, new research from the University of Copenhagen offers a fresh look at how coffee actually interacts with the human digestive system. Published in November 2026 in the journal Gut Microbiology, the study tracked 61 healthy Danish adults over nine days to examine how regular coffee consumption affects the gut. While earlier studies relied mainly on stool samples to examine gut bacteria, the Copenhagen researchers took a groundbreaking approach. They asked participants to swallow a tiny wireless sensor capsule that measured internal acidity, pressure, transit time, and muscle movements in real time as it travelled through the digestive tract. The study's main discovery is that regular coffee consumption is linked to measurable physical changes inside the gut, alongside a wider variety of gut bacteria. Specifically, researchers found two key physical effects: - More frequent colon contractions - A more acidic small intestine Participants with higher levels of caffeine breakdown products in their urine experienced more active muscle contractions in their colon. This helps keep intestinal muscles working and moves waste along. Frequent coffee drinkers, defined as those having one to five cups a day on more than three days a week, had a lower pH, meaning higher acidity, in their small intestine compared to rare drinkers. Scientists noted that while acidity in the small intestine plays a key role in breaking down food, it is not yet clear whether this shift is helpful or harmful. "Frequent coffee consumption appears to affect the physiology of the gut itself, in other words, how the gut functions," first author Francesca Bucci, a PhD student at the Department of Nutrition, Exercise and Sports at the University of Copenhagen, said. However, the findings also help explain why a single cup of coffee might not relieve constipation on demand. Despite the extra colon contractions, overall transit time through the digestive tract did not change dramatically between frequent and rare drinkers. Because the study observed everyday habits in a small group rather than running a controlled trial, it cannot prove coffee alone caused these effects. For reliable daily regularity, experts still recommend drinking plenty of water and eating fibre-rich foods.