One of the areas of medicine that is exploding right now is the study inside the walls of your digestive system. Research is showing a connection that until recently has not been understood. The link between digestion, your immune system and mood.
Have you ever "gone with your gut"? Turns out that is not just a figure of speech. Hidden inside the walls of your digestive system is what scientists call the enteric nervous system (ENS) or your second brain. Making this the only organ to boast its own independent nervous system. It is an intricate network of 100 million neurons imbedded in the gut wall. The gut and brain have the ability to have constant communication through the nervous system, hormones and immune system. We have understood the hormonal system for a little while now (fight or flight) but the underlying system, the immune system, is more complex and works at a cellular level.
We all start out at birth with a sterile gut environment but over the years with different bacterias we are exposed to where we live, toxins we take in on a daily basis and from use of antibiotics our gut's microbes are effected. This is important to be aware of because this effects so many different parts of our health.
1. Immune strength - The 100 trillion microbes that live inside the GI tract regulate digestion and metabolism. They extract and make vitamins and other nutrients from the foods you eat. They program the body's immune system. They build and maintain the gut wall.
2. Mental Health - this one may surprise you. It did me when I first learned of it. Gut bacteria have been associated with a number of mental health problems including anxiety and depression.
In 2011 a study was done where a strain of mice that are typically timid and shy were given a cocktail of antibiotics dramatically changing the composition of their gut bacteria. Their behavior completely changed. They became bold and adventurous just from this change in digestive system. https://www.ncbi.nlm.nih.gov/pubmed/21683077
If you still question how strong the gut and brain connection is think of this - Have you ever been nauseated before giving a big presentation? Or had stomach pain during times of stress?