Coffee’s Influence on Mood and Microbiome
Artem Varnitsyn / Alamy
Both caffeinated and decaffeinated coffee have been shown to enhance mood and cognitive performance, potentially through their beneficial effects on the gut microbiome.
Research indicates that coffee significantly impacts digestion, cognition, and mood by interacting with gut bacteria. While much of the existing literature emphasizes caffeine’s role, coffee is also abundant in polyphenols—plant compounds that gut bacteria transform into bioactive molecules associated with anti-inflammatory properties and cognitive enhancement.
To better understand these interactions, John Cryan and his team at University College Cork recruited 62 healthy volunteers. Half were regular coffee consumers, while the others abstained from coffee. Participants underwent a 14-day caffeine withdrawal followed by a 21-day reintroduction period, during which they consumed either caffeinated or decaffeinated coffee.
Researchers collected blood, saliva, urine, and stool samples to analyze physiological reactions to coffee compounds, alongside assessments of mood, cognition, stress, sleep, and behavior.
Results showed that caffeinated coffee drinkers reported lower anxiety levels and enhanced alertness, whereas decaf drinkers exhibited improved memory performance and sleep quality. Both coffee types correlated with decreased stress and depression levels.
Upon removing and reintroducing coffee, participants’ microbiomes underwent rapid changes, with both regular and decaf coffee leading to higher levels of beneficial gut bacteria. “We were taken aback by the system’s dynamic nature,” stated Cryan.
This study indicates that the cognitive benefits of coffee may be driven more by polyphenols than by caffeine, as improvements in cognitive scores were linked to specific polyphenol-derived metabolites found in urine samples.
According to team member Daniel Del Rio from the University of Parma, a critical next step is understanding how different coffee types impact the microbiome. “Not all coffee is created equal; even roasting levels significantly affect its chemical makeup.”
Nicola Segata, a researcher at Italy’s University of Trento, emphasizes the importance of this study but also warns against overstating the findings. “The study’s modest sample size may restrict the generalizability of its results,” he notes.
“This research offers valuable insights into how coffee consumption influences microbiome composition, suggesting that the human gut may adapt quickly to various diets and environments without genetic alteration,” adds Telmo Pievani from the University of Padua.
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Source: www.newscientist.com












