http://youtu.be/toqWjBwz76A
A long clip so here is what it is saying.
Neurotransmitters are part of the signalling system in the brain. The best known neurotransmitter is probably serotonin, but there are very many others a few of which we’ll meet in later blogs. Neurotransmitters are made in the gut from amino acids, which are the component parts of whole proteins. So if for various reasons like insufficient HCl, lack of digestive enzymes or damage to the gut lining, protein is not being broken down or absorbed properly, this can result in people who are depressed, anxious or don’t feel so good:
It can go the other way round and start with a bacterial infection in the gut or an overgrowth of candida and this will affect the brain and behaviour. Also infection can cause a low grade inflammation in the microvilli ((the walls of the small intestine are lined with tiny finger like projections through which nutrients are absorbed. They are prone to damage.)). So a dysfunctional gut leads to symptoms.
[The picture to the right. The upper picture is the intestinal damage done by viral gastroenteritis – look at the black line in the middle. The picture below is a healthy intestinal lining. It is possible to make out the microvilli at the top of the picture.]
It has been shown that stress management techniques like biofeedback, yoga, hypnosis etc help reduce the symptoms of IBS, so we know there is this connection back and forth from the brain to the gut and the gut to the brain. She goes through a few neurotransmitters and their direct effect on the gut, for example GABA- the happy neurotransmitter – relaxes the Lower Esophageal Sphincter and too much can result in GERD ((This is damage to the throat caused by stomach acid rising up the throat due to a weak LES. Main symptoms are heartburn, bloating, a chronic cough, difficulty swallowing)). Norepinephrine – a stress hormone/neurotransmitter – too much results in diarrhoea. Neurotensin inhibits the release of food from the stomach.
She continues about the gut brain axis being a 2 way process and that mental disorders go hand in hand with gut issues. For instance it is very common for those suffering from Ulcerative Colitis, Chrons disease, IBS or with a parasite infection to be on anti-depressants as well.
So a change in behaviour like a spell of insomnia or being really nervous about meeting a deadline sends messages to the brain which says, ‘I’m stressed in my gut’ (ie ‘I’ve got butterflies’ or ‘I’ve got the trots’). The digestive system runs on the relaxed nervous system called the parasympathetic nervous system. To work well we need to be peaceful. This is why many take a siesta after lunch. If we are stressed we don’t have a relaxed tummy which changes the gut bacteria and we get low grade inflammation in our gut that can cause symptoms.
Between 1997-2005 there was a study done on 1,641 patients with GI ((Gastrointestinal Disorders)) disorders. 84.1% had chronic anxiety related to bacterial overgrowth, H Pylori and Ulcerative colitis. 67% had periodic anxiety related to IBS and 27% had depression related to Coeliac and IBS. ((Addolorato G et al, In J Clin Pract. 2008 July; 62(7):1063-9)))
10 – 20% of adults in the US have IBS. Of these 70-90% have psychiatric comorbidity, mainly related to mood and anxiety disorders. 19% of schzophrenics have IBS. 46% of those with panic disorders have IBS.
Another study published in 2006 on 97,593 IBS patients, with a control group of 27,402 people, showed that those with IBS had between 40 – 80% higher odds of having migraines, fibromyalgia or depression ((BMC Gastroenterol. 2006 sep 28; 6:26)).