The Second Brain: How Gut Bacteria Shape Our Fears
Recent clinical trials have revealed a startling link between our digestive tract and our emotions. Investigators discovered that patients diagnosed with generalized anxiety disorder often exhibit a severely depleted diversity of Bifidobacterium in their gut microbiome. This bacteria is critical for producing gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter that dampens neural over-excitation. Using high-resolution fMRI, researchers demonstrated that when these patients were shown threatening faces, their amygdala—the brain's emotional alarm system—showed significantly higher activation compared to healthy controls, a response that normalized after a course of targeted probiotic therapy.
Adapted from a cognitive neuroscience review, 2023.
Outline two defining principles and concepts of the biological approach in psychology and briefly explain how this approach can be related to the article above.