Your morning cup of coffee might be doing you more good than just waking you up—according to a new study, coffee also has a positive impact on the a person’s microbiome, improving the health of the gut-brain axis.

Researchers from the University College Cork in Ireland examined how regular consumption of coffee—both caffeinated and decaffeinated—affects the gut microbiome.

The study showed that coffee notably increased the presence of good bacteria like Eggertella sp and Cryptobacterium curtum in coffee drinkers. Both bacteria are thought to play a role in eliminating unhealthy bacteria and stomach infections.

Decaffeinated coffee drinkers, meanwhile, showed improvements in learning and memory, which may have been a result of components like polyphenols that provide cognitive benefits.

Caffeinated coffee, meanwhile, was linked to reduced feelings of anxiety, as well as improved attention.

‘Only part of the story’

“Coffee is one of the richest sources of dietary polyphenols, yet most research has focused almost entirely on caffeine,” corresponding author of the study John Cryan told Newsweek in an email.

“We wanted to understand how coffee as a whole affects the microbiome, metabolism, mood and cognition. One of the biggest surprises was that decaffeinated coffee produced many of the same effects as regular coffee.

“That suggests caffeine is only part of the story, and that other coffee compounds, particularly polyphenols, may play a major role in shaping the gut–brain axis.”

Coffee’s Health Benefits

Coffee has previously been shown to have health benefits.

One 30-year study of women over the age of 70 found that they were significantly more likely to be living well if they consumed coffee during middle age.

Another study found that drinking black coffee reduced the risk of death from all causes.

The study from the University College Cork, meanwhile, showed that coffee has a positive impact on gut health, a major topic of interest.

Prebiotic sodas are gaining popularity, and gut health is increasingly linked to a number of health outcomes, including mental health.

Coffee’s Potential to be ‘Harnessed’

Gastrointestinal cancers are on the rise as well, particularly in American adults, which has drawn more attention to how people should take care of their gut microbiome.

“Our findings reveal the microbiome and neurological responses to coffee, as well as their potential long-term benefits for a healthier microbiome,” Cryan said in a press release.

“Coffee may modify what microbes do collectively and what metabolites they use.

“As the public continues to think about dietary changes for the right digestive balance, coffee has the potential to also be harnessed as a further intervention as part of a healthy balanced diet.”

‘More biologically complex’

Cryan added that “like many dietary factors,” coffee is best in moderation.

“We also found that habitual coffee drinkers showed higher impulsivity and emotional reactivity than non-drinkers, which highlights that the effects are not universally positive,” he told Newsweek.

According to Cryan, he is hopeful that as research progresses, they might be able to use diet and microbiome to “more precisely” support overall health and well-being.

“The main takeaway is that coffee is much more biologically complex than we tend to think,” Cyan said.

“It’s not simply a stimulant; it interacts with the gut microbiome, immune system, metabolism and brain simultaneously.”