Biological effects of coffee consumption

Research into coffee consumption highlights its diverse biological effects on the human body. Initial observations note that coffee contains hundreds of bioactive compounds that influence functions beyond alertness, including the stimulation of bowels, the potential worsening of reflux symptoms, and temporary increases in intraocular pressure for those with glaucoma.

Subsequent scientific studies, such as the PREDICT research involving over 1,000 participants, have identified that coffee has a significant impact on the gut microbiome. This influence appears to be one of the strongest connections among studied food and drink items. Findings indicate that these changes are not solely dependent on caffeine, as decaffeinated coffee also affects microbial composition. Specifically, certain bacteria like Lawsonibacter asaccharolyticus are significantly more prevalent in regular coffee drinkers. While these interactions highlight the complex communication of the brain-gut axis, researchers note that current findings do not yet prove that these microbial changes directly cause changes in cognitive functions.

Recent findings published in ‘Nature Microbiology’ and through the PREDICT study reinforce these links, noting that Lawsonibacter asaccharolyticus was found to be at least six times more prevalent in coffee drinkers than non-drinkers. Furthermore, a large-scale study by ZOE involving over 22,000 participants found that the microbiome signature of coffee drinkers is distinct enough to identify their consumption habits through bacterial analysis alone. These interactions remain a key component of the ‘gut-brain axis,’ where gut metabolites may influence mood and cognitive functions.