Serotonin (5-hydroxytryptamine; 5-HT) is mainly produced from enterochromaffin (EC) cells in gut.
5-HT plays a key role in secretory and sensorymotor functions in gut.
Changes in gut 5-HT signaling are observed in various gut disorders including inflammatory bowel disease (IBD).
5-HT plays an important role in immune cell function and angiogenesis during gut inflammation.
Gut-derived 5-HT plays a pivotal role in other biological processes such as in bone function and metabolic homeostasis.
Often called the ‘feel good hormone,’ serotonin acts as both a hormone and a neurotransmitter in our body. Low mood, depression, anxiety, and even autism are associated with altered serotonin levels. For all of its importance to mental wellbeing, you might expect that the brain is where we find most of the body’s serotonin, but it’s not. In fact, the gut contains the vast majority of the serotonin in our body.
Serotonin released within the gut has many effects locally, including regulating peristalsis, which is the normal rhythmic movement of the gut muscle that helps move contents along the way. Serotonin also regulates digestive secretions and the perception of pain or nausea. Excessive serotonin production, as in the food poisoning example, can cause significant gastrointestinal distress.
At this current time, it is believed that our gut bacteria can both, directly and indirectly, influence serotonin levels.