Story at-a-glance Butyrate, produced by gut bacteria when they ferment dietary fiber, acts as a signaling molecule in the gut-brain axis, influencing stress, pain tolerance, immunity and brain health Through multiple mechanisms, including specific enzyme inhibition and NF-κB pathway regulation, butyrate reduces neuroinflammation and protects against neurodegenerative conditions like Alzheimer's and Parkinson's disease Butyrate influences key neurotransmitters including GABA, serotonin and dopamine, while also increasing brain-derived neurotrophic factor (BDNF), which supports neuronal growth and cognitive function The vagus nerve serves as a communication highway between the gut and the brain, transmitting signals about butyrate levels that affect mood regulation, stress response and immune function Optimizing gut health through dietary fiber and homemade fermented foods helps promote butyrate production and maintain a healthy gut-brain connection