Gut Bacteria & Brain

Communication between gut bacteria and the brain or gut brain axis is a two way complex

network involving hormones, immune cells, neurotransmitters and the vagus nerve. Vagus nerve

is the longest and main nerve of the parasympathetic nervous system that controls digestion,

immune system, and heart rate. The function of vagus nerve is involuntary and are not

consciously controlled. The gut brain axis or the communication system between gut and the brain affects stress levels, mood and cognitive function. Gut bacteria can regulate the

production of serotonin (a biochemical that stimulates neuronal activity) and the early

development of neurons in ways that have lasting impacts on the brain circuits and behaviours.

Brain circuits are a network of interconnected neurons that process information in the brain when activated. Serotonin and dopamine are neurotransmitters that are produced by gut bacteria. Serotonin or “feel-good” chemicals regulate mood, appetite, digestion, sleep, cognitive function, memory, pain perception, and emotion. Serotonin is referred to as a happiness chemical and a normal level of serotonin promotes good feelings such as positive emotions, resilience to stress, happiness with a feeling of well-being . A balanced level of serotonin makes a person less anxious, calmer, and more content. Low levels of serotonin cause mood disorders such as anxiety, and depression. Chemicals such as dopamine, endorphins, and oxytocin are chemicals that affect happiness, pleasure, and satisfaction. About 90% of serotonin is produced in the GI system that regulates digestion, bowel function, appetite, gut protection, and overall quality of life.