A Sick Gut Can Cause Mental Problems
A Direct Reference From: Kellman, Raphael (2014-07-01). The Microbiome Diet: The Scientifically Proven Way to
Restore Your Gut Health and Achieve Permanent Weight Loss (pp. 25-26). Da Capo Press.

Did you know, for example , there are more nerves in the gut than in the spinal column ? These nerves transmit important messages to and from the brain, and a growing body of research suggests we cannot fully treat mental and psychiatric problems without taking the gut into account. Thatís because the relationship between the brain and the gut is very much a two-way street. When you are feeling stressed, anxious, or angry, your brain triggers a response from your adrenal system to flood your body with stress chemicals. These chemicals disrupt your digestion, often producing such symptoms as gas, bloating, heartburn (gastroesophageal reflux disease, or GERD), and, in the long run, weight gain.

Your gut produces neurotransmitters, the brain chemicals you need to feel calm, balanced, optimistic, energized, and focused. But when your GI tract is not functioning properly it cannot synthesize enough of these crucial chemicals. For example, serotonin is a crucial neurotransmitter for feeling optimistic and self-confident as well as a critical component of our ability to get good sleep. When your serotonin levels are disrupted you might feel hopeless , unsure of your own abilities, and blue while also struggling with anxiety, agitation, and insomnia. In more serious cases low serotonin levels can lead to a diagnosis of depression. Yet some 95 percent of our bodyís serotonin is located in the gut, where it helps regulate digestion. If our GI tract isnít functioning properly, it canít produce the serotonin we need either for good digestion or for feeling good.