Coffee Consumption Linked to Improved Mood, Stress, and Gut Health, Suggests Study
Ireland: A new study has found that drinking around four cups of coffee daily may positively influence mood and stress levels, potentially through changes in gut microbiota and related metabolites. These effects were observed with both caffeinated and decaffeinated coffee, suggesting that coffee’s impact extends beyond energy boost to gut-brain interactions.
A recent study published in Nature Communications by Serena Boscaini and colleagues from University College Cork sheds new light on how habitual coffee consumption influences the microbiota–gut–brain axis. This complex communication network links gut microbes with brain function, playing a crucial role in regulating mood, cognition, and overall physiological balance.
For this purpose, the researchers conducted a prospective study involving healthy participants, comparing habitual coffee drinkers with non-drinkers. The study included multiple phases—baseline assessment, a two-week coffee abstinence period, and a reintroduction phase with either caffeinated or decaffeinated coffee. Across these phases, the team evaluated gut microbiome composition, metabolite profiles, cognitive performance, mood, and physiological responses.
The study led to the following findings:
- Regular coffee consumption significantly altered gut microbiome composition.
- Higher levels of specific bacterial species, including Cryptobacterium and Eggerthella, were observed in coffee drinkers.
- Notable changes in microbial metabolites were identified with habitual coffee intake.
- Levels of beneficial compounds such as indole derivatives and the neurotransmitter gamma-aminobutyric acid (GABA) were reduced in coffee consumers.
- These findings suggest complex metabolic adaptations associated with coffee intake.
- Coffee consumption was linked to increased impulsivity and emotional reactivity compared to non-drinkers.
- Abstaining from coffee led to a reduction in impulsivity and emotional reactivity, indicating reversibility of these effects.
- Reintroduction of coffee, both caffeinated and decaffeinated, improved mood parameters.
- Reductions in stress, anxiety, and depressive symptoms were observed following coffee intake.
- Caffeinated coffee was associated with reduced anxiety and improvements in certain cognitive functions.
- Decaffeinated coffee showed benefits in memory, sleep quality, and physical activity.
The study showed that coffee’s effects extend beyond caffeine, as both caffeinated and decaffeinated forms altered gut microbiota and metabolite profiles, highlighting the role of bioactive compounds like polyphenols. Key metabolites, including theophylline and phenolic acids, were closely linked to microbial changes and cognitive outcomes, underscoring the connection between diet, gut health, and brain function.
Coffee intake was also associated with immune modulation, influencing inflammatory markers and cytokine responses, while gastrointestinal function remained largely unchanged, suggesting primarily metabolic and microbial effects.
Overall, the findings indicate that habitual coffee consumption shapes the gut microbiome and its metabolic activity, potentially impacting mood, cognition, and overall physiology, and supporting its role in modulating the gut–brain axis.
Reference:
Boscaini, S., Bastiaanssen, T. F., Moloney, G. M., Bergamo, F., Zeraik, L., Ferri, A., Irfan, M., Lindemann, T. I., Schneider, E., Meyyappan, A. C., Harold, K. B., Long-Smith, C. M., Carbia, C., J., K., De Alvarenga, J. F., Tosi, N., Del Rio, D., Rosi, A., Bresciani, L., . . . Cryan, J. F. (2026). Habitual coffee intake shapes the gut microbiome and modifies host physiology and cognition. Nature Communications, 17(1), 3439. https://doi.org/10.1038/s41467-026-71264-8
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