A scientific study carried out by the University of Copenhagen has found that drinking coffee regularly may affect the functioning of the digestive system, especially bowel movements and colon contractions and is also linked to greater diversity of gut bacteria.
The study was published in the journal "Gut Microbiology", which specialises in research on gut microorganisms, and aimed to explore the relationship between habitual coffee consumption and the physiological conditions inside the digestive system.
What does coffee do inside your digestive system?
The research team used a small electronic capsule that participants swallowed to track the changes that occurred as it travelled through the digestive system.
The capsule measured a set of indicators, including the time it took 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 according to how much coffee they consumed.
The first group consisted of people who drank between one and five cups of coffee a day on more than three of the eight days covered by the study, while the second group comprised people who drank coffee less frequently.
The results showed that people who consume coffee regularly have greater diversity in the microorganisms present in their intestines compared with participants who drink less coffee.
This finding is consistent with research suggesting that coffee may influence the composition of the gut microbiome, the community of bacteria and other microorganisms that live inside the digestive system.
Francesca Bucci, the lead researcher in the study and a PhD student in the Department of Nutrition, Exercise and Sports at the University of Copenhagen, said that regular coffee consumption seems to affect the physiology of the intestines.
One of the most notable results was that people who drink coffee regularly had much lower acidity levels in the small intestine than those who consume it less often.
The researchers also observed 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 in keeping bowel movements regular, as they help move waste along and may help prevent constipation and keep the intestinal muscles in good condition.
Bucci said that intestinal contractions can support proper digestion, help reduce constipation and help maintain the functional state of the intestinal muscles.
By contrast, the researchers are still unable to determine whether the lower level of acidity in the small intestine benefits health or could have negative effects.
Is coffee responsible for the changes?
The researchers stress 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 in 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 range of processes that take place inside 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 linked to the effects of coffee rather than being mere coincidence.
He pointed out 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 allows control over the amount of coffee participants drink, instead of merely observing their consumption habits and comparing the differences between them.
This type of study would help determine whether coffee is actually causing these changes and to understand the mechanisms through which it may affect bowel movements and contractions.
