CORK — University College Cork researchers published a study in Nature Communications investigating the microbiota-gut-brain axis and coffee consumption. The research linked habitual coffee intake to specific changes in gut bacteria and modifications in host physiology and cognition among healthy participants.

Following the two-week break, coffee was reintroduced to participants without them knowing whether it was caffeinated or decaffeinated. Half of the participants received decaffeinated coffee and half received caffeinated coffee. This blind reintroduction allowed researchers to isolate the effects of caffeine from other coffee constituents on the microbiome and mental health metrics.

Bacteria such as Eggertella sp. And Cryptobacterium curtum were more abundant among coffee drinkers than non-coffee drinkers. Researchers also observed higher levels of Firmicutes bacteria in coffee drinkers. Increased levels of Firmicutes have been associated with positive emotions in females, according to the study findings.

Mental health outcomes varied depending on the type of coffee consumed. Improved learning and memory were observed only among participants drinking decaffeinated coffee. In contrast, caffeinated coffee was associated with reduced feelings of anxiety and improved vigilance and attention. Both groups reported lower perceived stress, depression, and impulsivity scores after coffee was reintroduced.

Professor John Cryan said, \"Our findings reveal the microbiome and neurological responses to coffee, as well as their potential long-term benefits for a healthier microbiome.\" The study examined whether these effects occur independently of caffeine.

The study was sponsored by the Institute for Scientific Information on Coffee, a non-profit organization that supports research on coffee's health effects. Nature Communications is a peer-reviewed scientific journal that publishes interdisciplinary research across the natural sciences.

Chlorogenic acids, polysaccharides, and ester-bound phenolics may evade absorption in the small intestine. Colonic microbes ferment nondigestible coffee fractions to produce short-chain fatty acids. Initial hydrolysis of chlorogenic acids can involve esterase-producing bacteria including Eubacterium ramulus and Bifidobacterium.

Why It Matters

This research provides empirical data on how habitual coffee intake shapes the gut microbiome and modifies host physiology and cognition. By examining the microbiota-gut-brain axis, the study assesses whether these effects occur independently of caffeine, offering insights into the bidirectional communication pathway between the gut microbiome and the brain.

The findings suggest potential long-term benefits for a healthier microbiome through coffee consumption. The differentiation between caffeinated and decaffeinated coffee effects on learning, memory, anxiety, and attention indicates that specific components of coffee drive distinct neurological responses. This contributes to understanding how dietary habits influence mental health metrics via microbial pathways.

Timeline

A study published in Nature Communications investigated the microbiota-gut-brain axis and coffee consumption. A narrative review published in the journal Metabolites summarized evidence on the gastrointestinal fate, systemic availability, and microbial transformation of coffee constituents. The study was sponsored by the Institute for Scientific Information on Coffee.

What's New

The study involved 31 regular coffee drinkers and 31 non-coffee drinkers, with participants abstaining from coffee for two weeks as part of the experimental design. Researchers examined 31 regular coffee drinkers and 31 people who did not normally drink coffee.

Regular coffee drinkers were defined as those who consume 3-5 cups of coffee a day. Researchers observed substantial shifts in gut metabolite profiles among coffee drinkers when they stopped consuming coffee. Regular coffee drinkers stopped consuming coffee for two weeks during the study.

Researchers observed increased levels of Firmicutes bacteria in coffee drinkers, which has been associated with positive emotions in females. Professor John Cryan said, \"Our findings reveal the microbiome and neurological responses to coffee, as well as their potential long-term benefits for a healthier microbiome.\"