Recent research shows that irritation in the gut can send signals to the brain and change your mood (Hopkins Medicine, 2025). A study published in Nature (2025) found that people with depression had lower gut bacterial diversity and higher levels of bacteria linked to inflammation — suggesting a connection between gut imbalance and depressive symptoms. Researchers at Stanford Medicine (2025) also explained that communication between the gut and the brain — through the vagus nerve and chemical substances produced by gut bacteria — can affect conditions such as anxiety, long COVID, and Parkinson’s disease. These studies show that keeping your gut healthy is essential for your emotional and mental well-being. How do gut bacteria influence mood and brain function?