Your daily coffee habit may affect your brain and mood in unexpected ways, study finds

What happened: A small University College Cork study found that caffeinated and decaffeinated coffee were linked to changes in gut microbes, mood measures, and cognition in healthy adults. Key numbers: 62 healthy adults studied, 31 regular coffee drinkers and 31 non-drinkers. Why it matters: Both groups reported lower stress, depression and impulsivity after coffee was reintroduced. The study could not prove gut microbes caused the mood or cognitive changes, and an outside psychologist cautioned against broad conclusions from a small sample.

A small University College Cork study found that caffeinated and decaffeinated coffee were linked to changes in gut microbes, mood measures, and cognition in healthy adults.

Both groups reported lower stress, depression and impulsivity after coffee was reintroduced. The study could not prove gut microbes caused the mood or cognitive changes, and an outside psychologist cautioned against broad conclusions from a small sample.