Number 5.
General Tech
WIRED
A recent study published in *Nature Communications* examined how regular coffee drinking affects the gut‑brain axis in healthy adults, distinguishing caffeine’s role from other coffee compounds. Thirty‑one habitual coffee drinkers (3–5 cups daily) and thirty‑one non‑drinkers were compared, and participants also cycled through two‑week coffee abstinence followed by re‑introduction of either caffeinated or decaffeinated coffee. The results showed that coffee alters gut microbiota composition—boosting species such as *Eggerthella* and *Cryptobacterium curtum*—and reduces inflammatory markers while increasing anti‑inflammatory molecules, effects that persist even with decaffeinated coffee. Behaviorally, regular drinkers exhibited higher impulsiveness and emotional reactivity, which eased during the abstinence period, and both coffee types lowered perceived stress and depressive symptoms; caffeine‑rich coffee further improved anxiety and attention, whereas decaf enhanced memory, sleep quality, and activity. Cortisol levels remained unchanged, suggesting coffee mainly influences subjective stress perception. Overall, the study highlights coffee’s complex, caffeine‑independent modulation of the microbiome, metabolism, and neuro‑behavioral states, supporting its potential as a dietary intervention for gut and mental health.