Yogurt contains probiotics that boost mood by improving gut health. Probiotics nourish “good” bacteria in the digestive tract and create an optimal environment for producing key hormones related to mental health. Eating enough probiotics has also been associated with lower stress levels and anxiety, particularly because they help regulate mood.
Furthermore, decreasing gut inflammation increases tryptophan levels. Tryptophan is an important amino acid involved in the production of serotonin. Many SSRIs used to treat depression work by increasing serotonin levels just like probiotics. However, probiotics do this without the same risky side effects of SSRIs, so there is a relatively low risk of trying them as an alternative treatment.