Women's Health May 7, 2026 0 Comments

Unlock the Surprising Brain Boost Hidden in Your Daily Cup—Yes, Even Decaf!

Ever wonder if your morning cup of joe does more than just jolt you awake? Turns out, coffee might be quietly pulling strings behind the scenes—tweaking your gut microbiome, boosting your mood, and even tweaking those stress levels. Yeah, it’s wild. Even decaf fans are getting in on the perks, which begs the question: is coffee’s magic more than just caffeine’s buzz? A fresh study peeks into this gut-brain connection, suggesting that your brew could be a key player in this complex dance between your digestive system and your noggin. So before you sip that next cup, let’s dive into what science is uncovering about your favorite daily ritual—and how it might be quietly shaping your health in ways you never imagined. LEARN MORE

4 min read

A new small study suggests that drinking coffee might help improve your mood, gut microbiome, and other health metrics.

Interestingly, even decaf coffee drinkers reported benefits.

Study authors note that this new research highlights how everyday foods can have meaningful effects on the gut-brain axis.

Scientists are constantly learning more about how your gut communicates with your brain, and vice versa. Now, the latest research dives into the potential impact of coffee and how it impacts your gut-brain axis—and the findings are pretty cool.

A small study in Nature Communications found a clear difference in the gut microbiomes between people who drank coffee and those who didn’t. It also suggests that those changes may influence mood, stress, and certain cognitive measures—in coffee drinkers, at least.

We’re a long way off from suggesting that you should drink coffee to support your brain, but the study raises some questions about how your daily cup or two could be impacting your health. Here’s what you need to know.

Meet the experts: John Cryan, PhD, study co-author and chair at the Department of Anatomy and Neuroscience in the School of Medicine at University College Cork; Sushrut Jangi, MD, a gastroenterologist at Tufts Medical Center; and Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, California.

What did the study find?

For the study, researchers analyzed a slew of health metrics in 31 people who regularly drank coffee and 31 who didn’t. Among other things, the researchers tracked the participants’ coffee intake, diet, and mood (through a psychological assessment). They also took urine and stool samples to learn more about the participants’ gut microbiome.

The researchers then asked the coffee drinkers to stop drinking coffee for two weeks and avoid other sources of caffeine. After 14 days, these participants resumed coffee drinking. Half were secretly given decaf coffee, while the other half were given caffeinated coffee (the researchers didn’t tell the participants which one they were getting).

The participants continued drinking whichever coffee they were given for 21 days, while the researchers analyzed their gut microbiome, mood, and other health metrics throughout.

Interestingly, researchers found that people in both the decaf and caffeinated coffee groups reported mood improvements after drinking coffee again. Those included lower levels of stress, depression, and impulsivity.

They also found that people who had caffeinated coffee reported having better attention and less anxiety. People in the decaf group said they felt their learning, memory, physical activity, and sleep were better.

When they analyzed participants’ gut microbiomes, researchers found that certain metabolites (small molecules produced during metabolism) changed after participants stopped drinking coffee. However, they mostly returned after they resumed their coffee drinking.

People who drank coffee and those who did not also showed differences in their gut microbiomes. Coffee drinkers had higher levels of Cryptobacterium curtum (linked to oral health) and Eggertella sp. CAG:209 (linked with the breakdown of fats and vitamin absorption), and Firmicutes CAG:94 (associated with positive emotions in women).

How would coffee impact the gut in a positive way?

The study didn’t dive into the reason why or how coffee could impact the gut in a positive way, so it’s hard to say for sure. However, there are some theories.

“Our findings suggest that coffee does influence pathways linked to mood, stress, and cognition, but it’s nuanced,” says John Cryan, Ph.D., study co-author and chair at the Department of Anatomy and Neuroscience in the School of Medicine at University College Cork. “It’s more accurate to say it modulates brain-related processes through the gut microbiome and metabolism,” he continues. “The overall impact likely depends on the individual, the type of coffee, and how it fits into their broader lifestyle.”

We already know that coffee has physiological effects on the body, such as increasing heart rate, boosting metabolism, and heightening alertness, says Sushrut Jangi, M.D., a gastroenterologist at Tufts Medical Center. “This study does shed some light on how the microbiome may be mediating some of these effects,” he says. “For example, coffee may cause shifts in microbial metabolites, which then lead to mood and behavioral changes through the gut-brain axis.” This suggests that coffee may impact the brain, along with behavior via changes in the gut microbiome, he says.

Coffee can also help increase levels of neurotransmitters like acetylcholine, explains Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, California. Acetylcholine is linked to learning and memory.

How much coffee do you need to get the perks?

This particular study looked at people who drank around three to five cups of coffee a day. (During the 21-day intervention, they were given four sachets of instant coffee a day.)

Cryan notes that the study doesn’t specify a prescriptive amount of coffee to drink daily to reap the benefits. Three to five cups a day just so happened to be what they studied.

What should you do with this information?

It’s hard to say at this point. Again, the findings don’t suggest that you should suddenly take up a coffee habit for your gut and brain health if you don’t already drink it. But the results can make you feel pretty good while you’re sipping your daily cup if you’re already in the habit.

“The key message is that coffee is more than just caffeine—it’s a complex dietary exposure that interacts with the gut microbiome and, through that, can influence the brain and behavior,” Cryan says. “It also highlights a broader point: Everyday foods and drinks can have meaningful effects on the gut–brain axis.”

Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends, with work appearing in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives by the beach, and hopes to own a teacup pig and taco truck one day.

Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health.

She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter.

Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.