Coffee, Gut Health & Mood: ColumbiaDoctors Insights

Your morning coffee may be doing more than waking you up. New research shows coffee could affect your gut health—and even your mental well-being.

“This research is interesting—it suggests that coffee may have a positive influence on the gut, which may help explain some of coffee’s health benefits,” says Columbia dietitian Jamie Leskowitz, RD.

The study, published in Nature Communications, compared groups of healthy adults who do and do not drink coffee. It also looked at what happened when the coffee drinker group stopped drinking coffee for two weeks and started again.

The results? Both regular and decaf coffee positively changed the gut microbiome, the community of bacteria that lives in your digestive system. In addition, participants reported lower stress and improved mood after reintroducing coffee. That suggests coffee’s effects go beyond the energizing effects of caffeine and may involve the gut-brain connection.

What is the gut-brain link?

Scientists are increasingly focused on the “gut-brain axis”—the two-way communication between your digestive system and your brain. In other words, your gut health may affect more than digestion—it may also influence how you feel and think.

Coffee—which contains plant compounds that can act like prebiotics—appears to influence this system by feeding beneficial gut bacteria, which supports the chemical signals they produce. By helping these “good” bacteria thrive, coffee may indirectly influence the production of compounds that can affect mood, stress response, and overall brain health.

“In simple terms: What you drink may shape your gut, and your gut may then influence how you feel,” says Leskowitz.

How healthy is coffee?

Coffee isn’t a magic fix, but this study adds to growing evidence that it can be part of a healthy diet for many people. Moderate intake (about three to five cups a day for most adults) has already been linked to lower risk of several chronic diseases, such as Type 2 diabetes, cardiovascular disease, and liver disease.

Still, individual responses vary. Your gut microbiome—and how you process coffee—can be different from someone else’s.

“More coffee isn’t always better. How your body responds depends on your tolerance, sleep, medical history, and overall diet,” says Leskowitz. “And, of course, while these findings suggest coffee may play a positive role in gut health, further research is needed to help reveal specific functions of these bacteria strains.”

The bottom line is: While coffee’s effects on the microbiome may support both gut health and mood, keep your coffee consumption balanced—and pay attention to how your body responds.

Jamie Leskowitz, MS, RD, is a registered dietitian and certified diabetes care and education specialist at the Metabolic and Weight Control Center at Columbia.