New Research Reveals Mechanisms Behind Coffee’s Positive Effects on the Gut-Brain Axis
April 21, 2026 | Source: University College Cork, Ireland
New research from APC Microbiome Ireland, a world leading research centre at University College Cork, has comprehensively explored the mechanisms behind coffee’s positive effects on the gut-brain axis for the first time.
The study published in Nature Communications and sponsored by the Institute for Scientific Information on Coffee (ISIC), reveals how regular consumption of both caffeinated and decaffeinated coffee can affect the gut microbiome, and in turn influence mood and stress levels.
The benefits of coffee for both digestion and mood have been widely studied, but the exact mechanisms behind these effects have remained unclear. This research investigated how coffee consumption affects the microbiota-gut-brain axis – the bidirectional communication between the gut microbiome and the brain – through a wide range of measures.
31 coffee drinkers and 31 non-coffee drinkers were closely studied through a series of psychological tests, caffeine and food diaries, and stool and urine samples to understand changes in their microbiome and perceived mood or stress. ‘Coffee drinkers’ were set as those who regularly consume 3-5 cups of coffee a day – defined by the European Food Safety Authority (EFSA) as a safe and moderate amount for most people2.