Coffee intake shown to reshape gut microbiome and boost mood and cognition

Researchers at APC Microbiome Ireland, a centre within University College Cork, published a study in Nature Communications that examined how regular coffee consumption influences the gut‑brain axis. The trial involved 31 habitual coffee drinkers and 31 non‑drinkers; participants consumed three to five cups daily, either caffeinated or decaffeinated, after a two‑week coffee‑free wash‑out period.

Reintroduction of coffee led to measurable changes in intestinal metabolites and microbiota composition, including higher levels of Eggertella sp., Cryptobacterium curtum and Firmicutes, particularly in women. Both caffeinated and decaffeinated coffee improved psychological measures, reducing stress, depressive symptoms and impulsivity. Decaffeinated coffee was linked to better memory and learning, while caffeinated coffee enhanced attention, alertness and appeared to lower anxiety and inflammation.

The investigators concluded that coffee can modulate the gut microbiome and its metabolites, thereby influencing emotional state and cognitive function, suggesting a potential role for coffee as part of a healthy diet.