Low Serotonin and Gastrointestinal Disorders
Written by: Kevin Cann
Serotonin is one of our neurotransmitters that are responsible for our mood. If our serotonin levels fall off we may experience anxiety and depression. More information about serotonin can be found in a previous article I wrote here, http://robbwolf.com/2012/10/05/serotonin-deficiency-food-cravings/. What many people do not understand is that serotonin also plays a role in gastrointestinal disorders. In fact, the majority of our serotonin is produced in the gut, roughly 95%.
Serotonin is produced in the enterochromaffin cells (EC) in the intestinal mucosa. Serotonin is produced, and then it bonds with its receptors. These receptors are known as the 5-hydroxytryptomine receptors, or as they will be referred to here on out as 5-HT receptors. Once the serotonin is released, it activates our system to increase intestinal motility. Research has shown that there is an increase in plasma 5-HT during diarrheal diseases, and a decrease in them when constipation is present (Cammilleri, 2009).
These receptor sites are actually targets for medications when treating diarrhea and nausea. 5-HT (3) receptor antagonists are used during chemotherapy treatment to help alleviate symptoms and 5-HT (4) agonists are used to help treat constipation (Costedio, 2007). Therefore, if we have too little, or too much serotonin floating around we can experience all kinds of common gut issues.
Selective Serotonin Reuptake Inhibitors (SSRIs) are the most commonly prescribed antidepressants. They too work upon the same serotonin pathways to help aid in depression. Common side effects of SSRIs are nausea, diarrhea, and nervousness. All issues associated with improper levels of plasma 5-HT receptors.
The new path of the medical community seems to be leading towards drugs that affect the serotogenic pathways to treat IBS. One such drug is a 5-HT antagonist and it is called Alosetron. In one study, Alosetron showed to be beneficial in treating global IBS symptoms in women with IBS that were experiencing diarrhea symptoms. This was after conventional therapy had failed (Mayer, 2003). Studies have even shown it beneficial in reducing symptoms of anxiety.
On the other end of the spectrum we have IBS with constipation. Treatment for this is leading to medications that act as 5-HT agonists. One of those drugs is Renzapride. Cammilleri and colleagues showed that Renzapride was associated with improvement of bowel function in women (Cammilleri, 2004).
The Understanding of IBS and its roots are still up in there. Chances are it is not just caused from one factor. What we do know is that poor gut health can lead to poor mood and vice versa. Our serotonin pathways may be a large player in this part. Due to this understanding, we want to take action in making sure we have adequate serotonin. We do this by getting proper sleep, having proper vitamin D levels, getting sufficient sunlight, not drinking too much alcohol or coffee, and eating high quality protein. We need to make sure we also have good digestive health. Without proper digestion, the tryptophan and the nutrients required to convert it into serotonin may not be present.
If you are suffering from IBS and dietary changes and conventional therapies are not working, you may want to seek out a qualified health practitioner and have your serotonin levels checked. Simple 5-HTP, or L-tryptophan supplementation may be all you need to help alleviate specific symptoms. The other neurotransmitters may also play a role in IBS as well, and I will discuss those in future articles. The vagus nerve that allows for communication between our gut and our brain is a two way street. Sometimes healing the mind will heal the gut and vice versa. Eat nutrient dense foods and manage your stress, and you will be surprised at how far just those two little things can take you.