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Improving Your Digestive Health


This is the first in a series on gastrointestinal health.


Have you ever had “butterflies” in your stomach before making a speech or eating a tub of ice cream because you’re feeling down? Then you have already experienced the connection between the brain and the gut. The brain and the digestive system are linked by complex pathways that allow information to flow back and forth continually. So certain feelings and thoughts can stimulate reactions in the gut while sensitized nerves in the gut can trigger changes in the brain.


The human nervous system consists of two main parts the central nervous system (CNS) and the peripheral nervous system (PNS). The brain and spinal cord are part of the CNS, while the PNS consists mainly of the nerves that connect the CNS to the rest of the body. The PNS is comprised of the somatic nervous system (SNS) and the autonomic nervous system (ANS). The enteric nervous system (ENS) is a semi-independent part of the ANS whose function is to control the gastrointestinal (GI) system.


The ENS is a network of more than 100 million neurons, neurotransmitters and protein with a complex neuronal circuitry that enables it to control the digestive system separate from the brain’s impulses. On an ongoing basis the gut must assess conditions such as: progression of digestion, presence of nutrients and acidity levels along with many others and then decide on a course of action and initiate a reflex. This continues even if the connection between the ENS and the brain is severed.


The enteric nervous system was first described by Dr. John Newport Langley in 1921 and it was coined the “second brain” by Dr. Michael D. Gershon in 1996 in reference to the complexity of its functions. At first the idea of a second brain was ridiculed but the concept that the enteric nervous system using some of the same neurotransmitters as the brain has become more accepted in the scientific community. It explains why conditions such as anxiety, irritable bowel syndrome and ulcers manifest symptoms in both the brain and in the gut.


Stress affects the digestive system in a number of ways. In response to a stressor the brain triggers a response along two bodily paths: the hypothalamic-pituitary-adrenal axis and the autonomic nervous system. The resulting increased secretion of cortisol, adrenaline and noradrenaline directly affects the ENS. Corticotrophin-releasing-factor (CRF) a peptide found in both the brain and gut is another substance that appears to have significance in the stress response. CRF increases anxiety-like behavior, abdominal pain, colon secretions, muscle contraction and increased permeability in the lining of the bowel. CRF also stimulates an immune cell called mast cells. When mast cells are activated an immune response resulting in mucosal inflammation occurs. This also stimulates the release of cytokines which generates an acute stimulation of the hypothalamic-pituitary-adrenal axis. So the cycle of chronic inflammation begins, GI inflammation triggers an increased firing of the gut’s sensory neurons culminating in sensory hyperactivity. Serotonin is also a key player in the gut-brain dynamics it acts as a go between keeping the brain up to date on what is happening in the gut. This important neurotransmitter essential to our overall well-being is stored at 96% in the ENS where it is synthesized. Researchers are beginning to believe that a happy gut is a happy mind.


We are all born with a sterile gut but over time it gets colonized by a diverse brew of bacterial species. What bacterial species are present in the gut is determined by genetics and by the bacteria surrounding us. Researchers have found that the gut microbiome can influence neural development, brain chemistry and a wide range of behavioral responses. In a 2011 study mice were fed a solution of the probiotic Lactobacillus rhamnous after 28 days the researches subjected the mice to a series of tests to detect signs of anxiety and depression. The mice fed the probiotic solution showed less fear response behavior and anxiety to the control group. Probiotic fed mice also produced lower levels of the stress hormone corticosterone.


To help support a healthy GI system we have designed the Digestive Relief Daily Pack. Also consider including a probiotic such as AOR Advanced Biotics or Pure encapsulations™ Digestive Enzyme Ultra to your daily nutritional regime. Feeling stressed out consider using the adaptogenic herbs AOR Rhodiola Rosea with Ginseng or AOR Zen Theanine.


References


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2. Rubin RP. A Brief History of Great Discoveries in Pharmacology: In Celebration of the Centennial Anniversary of the Founding of the American Society of Pharmacology and Experimental Therapeutics. Pharmacological Reviews. 2007; 59: 289-359.

3. American Association of Anatomists. Available at: http://www.anatomy.org/content/michael-gershon Accessibility verified February 20th, 2012.

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13. Bravo JA, Forsythe P, Chew MV, et al. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci U S A. 2011; 108:16050-160505.

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15. Bercik, P., Verdu, E.F., Foster’ J.A., Macri, J., Potter’ M., Huang, X., Malinowski, P., Jackson, W., et al. Chronic Gastrointestinal Inflammation Induces Anxiety-Like Behavior and Alters Central Nervous System Biochemistry in Mice. Gastroenterology. 2010 Dec;139(6):2102-2112