Overview
- APC Microbiome Ireland reported in Nature Communications on Tuesday that regular caffeinated or decaf coffee changed gut microbes, with higher Cryptobacterium, Eggerthella, and Firmicutes, and that these shifts tracked with lower stress.
- The study followed 31 habitual coffee drinkers and 31 non-drinkers, asked drinkers to stop for two weeks, then reintroduced coffee in a blinded caffeinated or decaf form.
- After reintroduction, participants recorded lower perceived stress, depression, and impulsivity regardless of whether their coffee contained caffeine.
- Caffeinated coffee correlated with less anxiety and sharper vigilance and attention, while only decaf was linked to gains in learning and memory.
- Researchers cautioned that the sample was small, the protocol was short, and the work was sponsored by the Institute for Scientific Information on Coffee, and they called for larger independent trials.