The dietary fiber and anthocyanins in blueberries have the potential to influence the gut microbiome and metabolites relevant to depression in older adults https://medicalxpress.com/news/2026-09-blueberries-gut-microbiome-older-adults.html Daily blueberry intake modulates the gut microbiota in older adults https://www.sciencedirect.com/science/article/pii/S1279770726001910

Coffee changes gut microbes linked to mood and brain function; both caffeinated and decaf coffee were associated with lower stress https://timesofindia.indiatimes.com/science/discovery/scientists-found-that-coffee-changes-gut-microbes-linked-to-mood-and-brain-function-both-caffeinated-and-decaf-coffee-were-associated-with-lower-stress-depression-and-impulsivity-in-a-new-study/articleshow/134557258.cms Habitual coffee intake shapes the gut microbiome and modifies host physiology and cognition https://www.nature.com/articles/s41467-026-71264-8 Those who drank caffeinated coffee reported feeling less anxious and less psychologically distressed. Caffeinated coffee has also been linked to greater vigilance and attention. Decaffeinated coffee, meanwhile, was linked to improvements in learning and episodic memory, as well as better sleep quality and increased physical activity