This Everyday Drink Was Linked To A More Diverse Gut Microbiome
That first cup of coffee does more than help you wake up.
It also delivers plant compounds that interact with the trillions of bacteria living in your gut. Could your daily coffee habit influence which microbes thrive there?
A recent study1 explored this question, looking at how often people drank coffee and whether their habits were linked to differences in gut bacteria and digestive function.
About the study
Coffee contains more than caffeine. It's also rich in polyphenols, plant compounds that gut bacteria can break down. The goal was to understand how regular coffee intake relates to the gut microbiome and digestive activity.
The study followed 61 healthy adults for nine days, collecting food and drink diaries, urine, and stool samples.
Some participants also swallowed a wireless capsule that measured digestive activity, including muscle contractions and acidity levels.
Based on their diaries, participants were split into two groups: rare coffee drinkers (fewer than three days of coffee consumption) and frequent drinkers (more than three days).
Frequent coffee drinkers had more diverse gut bacteria
Despite having similar ages, BMIs, and overall diets, the two groups had different gut microbiomes.
Frequent coffee drinkers had a greater variety of gut bacteria, including higher amounts of certain microbes that break down plant compounds found in coffee.
Digestive activity differed, too. Markers of caffeine breakdown were associated with stronger contractions in the colon, which helps move digested food through the gut.
Frequent drinkers also had a lower pH, meaning more acidic conditions, in their small intestine. Since acidity influences which microbes can thrive, this may help explain some of the differences in bacterial populations.
Why gut bacteria diversity matters
Your gut microbiome plays a well-established role in your overall health, including breaking down food compounds your body can't digest on its own.
A greater variety of bacteria is generally associated with a more resilient gut ecosystem, as different microbes contribute different functions.
Coffee may influence this environment through both its polyphenols and caffeine. Polyphenols provide compounds that certain bacteria can break down, while caffeine may affect digestive movement.
Together, these effects could help shape the gut environment, although exactly how isn't yet clear. Since the study observed people's existing habits, it can't tell us whether coffee caused these differences.
How to make the most of your coffee habit
If you enjoy coffee, there's no need to change your routine based on this study alone. A few details from the study can help put your next cup in context:
- Pay attention to how your gut responds: Coffee can stimulate digestive activity, and some people feel the urge to use the bathroom soon after a cup. If your usual amount doesn't sit well with you, it's fine to adjust it.
- Don't assume more is better: Frequent coffee drinkers had more diverse gut bacteria in this study, but the study didn't establish an ideal daily amount or prove that drinking more causes these benefits.
- Remember that coffee isn't just caffeine: Its polyphenol content can vary depending on the beans, roasting, and brewing method. These differences may influence its effects on gut bacteria.
- Don't rule out decaf: The study didn't establish whether decaffeinated coffee has similar effects. Since coffee contains beneficial plant compounds beyond caffeine, it's an interesting area for future research.
The takeaway
Your morning coffee may be doing more for your gut than keeping you alert. Frequent coffee drinkers in this small study had more diverse gut bacteria and differences in digestive activity, although larger, longer studies are needed to understand the connection.