Sixty-one healthy Danish adults swallowed a small electronic capsule to measure transit time, temperature, pH, and contractions, as L’Université de Copenhague announced on Tuesday that regular coffee drinkers process digestion differently than those who drink little.
The study, published in the peer-reviewed journal Gut Microbiology, followed the participants over eight days to track direct measurements on a poorly understood physiological link. Researchers analyzed stool samples to examine gut bacteria alongside the internal sensor data. Participants were split into frequent consumers, who drink one to five cups daily for more than three days of the study period, and non-frequent consumers.
Frequent consumers showed a higher diversity of microorganisms in the gut. Their small intestine also had a lower pH, and higher coffee consumption correlated with increased colon contractions. However, lead author Francesca Bucci, a doctoral student, emphasized that function matters more than flora.
“But more important especially, frequent coffee consumption seems to affect the gut physiology itself, meaning how it works.”
The study did not specify the exact health impact of a lower pH level.
The research team acknowledged that the study cannot prove coffee is the sole cause of these physiological differences. Yet team leader Henrik Munch Roager, an associate professor, pointed to prior work and common consumer experience to argue that coffee plays a central role in these digestive processes.
“We already know from other studies that coffee can influence several processes of the digestive system, including acid secretion in the stomach. There is therefore good reason to believe that what we observe is not a mere coincidence. Many people also recount that coffee acts on their digestion.”
Roager said an intervention study should follow, where researchers control coffee intake to compare high and low consumption periods. Such work could eventually help experts stimulate bowel movements naturally.
Coffee already holds associations with a reduced risk of cardiovascular diseases, diabetes, depression, and several cancers, according to university data. The beverage contains more than 1,000 bioactive compounds, keeping its exact mechanisms of action complex and difficult to isolate.
- Direct Measurement: Researchers used an ingestible electronic capsule to track pH, temperature, and muscle contractions directly inside the gastrointestinal tract.
- Microbial Diversity: Regular coffee drinkers showed a wider variety of gut bacteria alongside a more acidic small intestine.
- Motility Impact: Higher intake correlated with increased physical contractions in the colon, which may assist with transit speed.
- Regular coffee drinkers show distinct gut motility and diverse microbiome. Gut Microbiology.
