Regular coffee consumption modifies gut bacteria and digestive physiology

If you drink coffee regularly, it appears to alter not only your gut bacteria, but also the physiology of the gut itself. This is the conclusion of a study from the University of Copenhagen, which could pave the way for better treatments for constipation.

It may be a bit of a touchy subject, but many of us know that feeling: that cup of coffee that makes things happen.

Research now suggests that regular coffee consumption affects the functioning of our digestive system.

A research team from the University of Copenhagen asked a group of Danish participants to swallow a small electronic capsule. As it moved through the digestive tract, the capsule measured, among other things, transit time in the gastrointestinal system, temperature, pH and intestinal contractions.

Participants were categorized as frequent coffee drinkers, defined as consuming between one and five cups per day for more than three of the eight study days, and drinking coffee less often.

Above all, the results confirmed that coffee affects the composition of intestinal bacteria, as previous studies suggested. Frequent coffee drinkers had a greater diversity of microorganisms in their gut than those who drank it less frequently.

But perhaps more importantly, frequent coffee consumption appears to affect the physiology of the gut itself, in other words how it functions. »

Francesca Bucci, first author, PhD student, Department of Nutrition, Exercise and Sports, University of Copenhagen

It is already well established that moderate coffee consumption is associated with a reduced risk of cardiovascular disease, diabetes, depression and several types of cancer. However, much less is known about the link between habitual coffee consumption and physiological conditions of the gut.

Stimulates intestinal contractions

Researchers found that frequent coffee drinkers had significantly lower pH in the small intestine than those who drank coffee less often. They also observed that higher coffee consumption was associated with more colon contractions.

So are these physiological differences beneficial or not?

“Intestinal contractions can promote healthy digestion, help prevent constipation and keep intestinal muscles in good condition,” explains Francesca Bucci.

Researchers cannot yet determine whether lower pH is beneficial or harmful to health. However, the pH level in the small intestine plays an important role in the activity of digestive enzymes and how food is broken down.

The researchers also point out that the study cannot establish whether the differences are solely caused by coffee consumption. Nevertheless, lead author Henrik Munch Roager believes there is good reason to believe that coffee plays a key role.

“For example, we already know from other studies that coffee can influence a series of processes in the digestive system, including the secretion of acid in the stomach. So there is good reason to believe that what we are seeing is not just a coincidence. Anecdotally, many people also report that coffee affects their digestion,” says Henrik Munch Roager, associate professor and head of the research group in the Department of Nutrition, Exercise and Sport.

Calls to continue studies

According to Roager, the natural next step would be an intervention study in which researchers control the amount of coffee participants drink and examine what happens to gut physiology during periods of high coffee consumption compared to periods without coffee.

Researchers hope these and future findings can help solve a widespread problem.

“Many people suffer from constipation and irregular bowel movements. If we can understand how coffee affects digestion and intestinal contractions, it may be possible to use this knowledge to stimulate intestinal motility in a natural way. This would be extremely valuable,” says Henrik Munch Roager.