A controlled study reports that regular coffee consumption may influence gut microbiota while coinciding with lower levels of stress, depression, and impulsivity.
By yourNEWS Media Newsroom
Researchers at APC Microbiome Ireland at University College Cork have identified measurable biological and psychological changes associated with routine coffee consumption, according to findings published April 24, 2026, in Nature Communications.
The investigation analyzed 62 participants divided into habitual coffee drinkers and individuals who did not consume coffee. Scientists focused on the gut-brain axis, a system describing how the digestive tract and central nervous system communicate through biochemical signaling.
Participants who regularly consumed between three and five cups per day were instructed to stop drinking coffee for two weeks. During that period, researchers documented notable shifts in the gut microbiome, referring to the population of microorganisms in the digestive system. When coffee intake resumed, participants reported reductions in stress, depressive symptoms, and impulsive behavior.
Microbial analysis showed that individuals who consumed coffee had elevated levels of certain bacterial strains, including Eggerthella and Cryptobacterium curtum. These microorganisms are associated with digestive processes and may contribute to regulating harmful bacteria. Researchers also observed an increase in bacterial species previously linked to improved emotional states in women. These changes were present in both caffeinated and decaffeinated groups, indicating that coffee’s effects extend beyond caffeine content.
Lead author Professor John Cryan stated that coffee appears to influence microbial activity and metabolic processes within the gut, suggesting that its compounds may alter how bacteria function collectively.
Following the reintroduction of coffee, participants consistently reported improvements in mood-related measures. Researchers noted that coffee contains polyphenols and micronutrients known to reduce inflammation and oxidative stress, which may affect neurotransmitter function, including pathways involving serotonin.
Additional observations highlighted differences between caffeinated and decaffeinated varieties. Decaffeinated coffee was associated with enhanced learning and memory performance, while caffeinated coffee correlated with reduced anxiety levels, improved alertness, and increased attention. These findings suggest that both caffeine and non-caffeine compounds contribute to cognitive and emotional effects.
Experts cited in related commentary indicated that coffee’s impact is likely due to a combination of bioactive substances rather than a single ingredient. Compounds present in coffee may influence both neurological activity and gut microbial balance simultaneously.
The research team emphasized that coffee should be considered part of a broader dietary pattern rather than a primary intervention. While the sample size was limited, the findings contribute to ongoing research examining how nutrition affects mental health through gut-related mechanisms.
The study’s authors concluded that coffee may serve as a supportive dietary component for maintaining digestive and psychological health, particularly when incorporated into a balanced lifestyle.
Source: Natural News
Original article
Comments