The Direct Hotline from Mouth to Gut. A Primer on the 'Gut-Brain Axis (Priming)' Where 'Chewing' Travels Down the Vagus Nerve to Turn ON the Power of the Massive Digestive Organs

After eating a steak, do you suffer from a heavy stomach? Or is it digested cleanly by the next morning, leaving you full of vitality?

Many people blame “the food they ate” or “the specs of their internal organs” for the cause of indigestion, saying things like “because the meat was greasy” or “because my gastrointestinal tract is weak.” However, the physiological truth is completely different. The biggest reason why your stomach and intestines are screaming is because a massive chunk of unprocessed protein (bolus) was suddenly thrown down into them from above when they “weren’t ready to start working (digesting).”

The kitchen of an excellent restaurant doesn’t start the fire or chop vegetables after an order comes in. They “complete preparations (standby) before it even enters your mouth.” The only act that sends an advance hotline (powerful electrical signal) to this massive kitchen of the human body (the digestive system), declaring “A massive amount of food is about to be dropped!”, is the physical hack of “chewing off to the limit of mastication (chewing priming).”

The Ferocity of the “Cephalic Phase Response” Triggered by Chewing

The moment food enters your mouth, you taste it, and “bite down powerfully.” Even though you haven’t even swallowed the first bite, dramatic chemical reaction switches have already been pressed inside your body. This is called the “Cephalic Phase Response” (pre-digestion phase activation in E05).

1. Passing the Baton from the Trigeminal Nerve to the Vagus Nerve: The intense drag force when a hard object is crushed with a “crunch” by the back teeth is converted into an electrical signal at the root of the tooth (periodontal ligament), rushes up the trigeminal nerve at breakneck speed, and reaches the dorsal motor nucleus of the vagus nerve in the brain (medulla oblongata). From here, a general order to “boot up all at once” is issued to the entire system of digestive organs through a thick optical fiber network (vagus nerve) extending to the stomach and pancreas.
2. A Shower of Digestive Juices and an Explosion of Blood Flow: At the moment of this chewing signal, the stomach lining opens its proton pumps completely and begins to release powerful “gastric acid (hydrochloric acid)” and a protein-degrading enzyme (pepsinogen) like pouring rain. At the same time, the pancreas promotes the initial secretion of insulin (priming of pancreatic β cells), and the gallbladder creates a standby state for sludgy bile to emulsify lipids (endocrine linkage from the cephalic phase related to E02). The blood flow volume of the gastrointestinal tract (operation of the celiac artery) rises all at once, and their idling reaches its MAX state.

The Terrorism Against Internal Organs Caused by “Fast Eating Without Chewing”

Conversely, if you drop a hamburger or beef bowl into your stomach in 5 minutes after chewing only a few times (or washing it down with water), this “siren of the cephalic phase” does not sound at all.

While the kitchen staff (stomach and intestines) are completely off guard and resting (sympathetic nervous system OFF, lack of vagus nerve preparation), a massive chunk of meat and fat suddenly rains down. They frantically try to secrete stomach acid but aren’t in time; it becomes putrefactive matter without being sufficiently digested (peptidized), falls prey to bad bacteria in the intestinal tract, and causes intense gas (flatulence), unprecedented stomach heaviness, and rough skin (leaky gut syndrome) (collapse of the intestinal environment related to E14).

Before taking stomach medicine, or spending money on probiotics (intestinal regulators), you should immediately stop the “outrageous act of launching a surprise attack on the stomach and intestines without warning (fast eating).” The starter switch for operating the massive infrastructure of the digestive system is not installed inside your stomach, but only in the “sturdy jaw and teeth (masticatory organs)” located at the highest position.