New Delhi: Researchers from Ireland have comprehensively explored the mechanisms behind coffee’s positive effect on the gut-brain axis for the first time.
The study reveals that the consumption of both caffeinated and decaffeinated coffee has a positive influence on the gut microbiome, which in turns influences mood and stress levels. The benefits of coffee on digestion and mood have been widely studied, but the underlying mechanisms have remained largely unclear. The research investigated how coffee consumption affects the microbiota-gut-brain axis, the bidirectional communication system between the gastrointestinal tract and the brain.
31 coffee drinkers and 31 non-coffee drinkers were studied closely through a series of psychological tests, caffeine and food diaries, as well as stool and urine samples to understand changes in their microbiome and perceived mood or stress. Those who regularly consumed three to five cups of coffee a day were designated as coffee drinkers. Participants abstained from coffee for two-weeks with regular psychological assessments and samples. The abstinence period corresponded with significant changes in metabolite profiles in the gut microbiome, compared to non-coffee drinkers. Coffee was reintroduced to regular drinkers, with half the participants consuming decaffeinated coffee. Both groups reported lower stress, depression and impulsivity scores, suggesting that coffee improved mood, regardless of caffeine content.
An increase in beneficial bacteria
Bacteria that contribute to gastric and intestinal acid secretion, as well as bile acid synthesis were found to increase notable in coffee drinkers compared to non-coffee drinkers. The gastric acids play a role in eliminating unhealthy gut bacteria and stomach infections. Bacteria associated with positive emotions in females were also seen increasing. The researchers also noted an improvement in learning and memory among those who consumed decaffeinated coffee, suggesting components other than caffeine were responsible for cognitive benefits. Caffeine was associated with reduced feelings of anxiety, improved vigilance and attention, as well as reduced risk of inflammation. A paper describing the research has been published in Nature Communications.
