A 2023 study from the Harvard T.H. Chan School of Public Health found that people who consume nine or more servings of ultra-processed foods a day have a 50 per cent higher risk of developing depression than those who eat four or fewer daily servings. Researchers have long been highlighting the importance of the gut-brain connection — the idea that the gut and brain constantly communicate through an intricate network of nerves and chemical signals. The gut microbiome, the col