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A Guided Tour Through the Gut

A Guided Tour Through The Gut


Have you ever thought about what happens to your food after you swallow it?  As a kid, I pondered this question.  Mainly because I was chronically constipated and it seemed like my food just kind of “disappeared”.  I had stomach aches A LOT!  My belly poked out, even though I was a string bean, and I wondered why.  As I got older, I had bad acne and a mouth full of filled cavities.  This was because I wasn’t eating the right foods, and because my digestion was weak. I wasn’t absorbing much of the nutrition from the food I was eating.  Nutrition is not just about what you eat, it’s also about what you are able to digest!!!


If someone would have taught me (and my Mom) about nutrition and digestion, I would have had a much easier childhood, adolescence, and less problems as an adult.  Being able to listen to our body’s signals and having a general idea about what these signals could mean are the key in preserving good health and preventing unnecessary health complications in the long run.


During my time at Polaris Tech, a handful of students expressed to me that they had stomach issues.  Some of them chronic and much worse than what I experienced as a kid.  So I thought it would be a very good idea to take them on a guided tour through the gut in hopes that this information might help them troubleshoot some of these issues...and now it’s your turn!!!  


All Aboard???


  1. Digestion is a North to South Process that Starts in the Brain!

    Just thinking about food is enough to make your mouth water and your tummy grumble!  That’s because your brain is preparing you for your nutrient dense, healthy meal.  This is your mind-body connection at work!

  2. First Stop - The Mouth

    Once you take that first mouth watering bite of your meal, salivary enzymes in the mouth get to work starting the chemical breakdown of your food.  Carbohydrates literally melt in your mouth and are almost completely digested even before you swallow them. There is some hormone signaling at this stage too that helps your body prepare for the incoming of food.  Chewing does the mechanical work and these combined efforts liquefy your food into what’s called a Bolus.  The Bolus is swallowed and begins the descent south through the esophagus to the next stop on our tour.

  3. Next Stop - The Stomach (A.K.A. Acid Tank)               

    The pH of your stomach juices should be a “burn a whole in the rug” pH of 1.5 – 3!  Stomach acid is one of the strongest acids on the planet!!!  The acidity of the stomach acid triggers digestive enzymes to be released from special cells in the stomach lining that are necessary for breaking down proteins into peptides and amino acids. This acid also kills bacteria and parasitic hitchhikers from your food and treats them just like any other protein. A layer of Mucus protects the stomach lining from being burned by the strong stomach acid.  Combined with the churning motions of the powerful stomach muscles the Bolus is converted into an acidic paste called Chyme.  Only when the chyme is at the appropriate pH, a signal is sent for the door to open (pyloric sphincter) to the next stop on our tour.

  4. Absorption Processing Factory - Curve in the Road

    The Duodenum is the first section of the Small Intestine.  It is shaped like a curve and is a busy place.  There are a couple factories in this part of town that keep business working as usual.

    1. The Pancreas - Makes and secretes Bicarb (Baking Soda) which alkalizes the strong acidic chyme.  This is important because otherwise the acidic chyme would burn your intestines (duodenal ulcer).  The pancreas also makes and secretes Pancreatic Enzymes. These little mechanics work hard to break down the big molecules left from your food into smaller, absorbable molecules.  

    2. The Gallbladder - In the presence of fat, the gallbladder receives a signal from the duodenum to secrete Bile.  Bile acts like dish soap to fats emulsifying them from big globs, into smaller fat globs.  This helps the pancreatic enzymes do their job of busting the fat globs into small “absorbable” molecules.

           These two factories (organs) send their products into the duodenum to be used in the
    complete breakdown of food particles. If these organs do their jobs proficiently, the food
    molecules and nutrients should be ready for absorption by the cells and “finger-like”   

protrusions that line the small intestine.


  1. Very long winding road - Small Intestines

    This is where the majority of your nutrient absorption happens.  Nutrients from food diffuse into the cells lining your intestines and are pulled into the bloodstream.  

    Fibers and other molecules that are too large cannot be absorbed and continue through the small intestine.  Large protein particles and rancid fat molecules can cause damage to those “finger like” protrusions and eventually damage and inflame the small intestine.  Undigested food becomes fair game for gut bacterial as well.  Too much gut bacteria in the small intestine can cause symptoms of IBS. 

    ***NOTE - The intestines are also home to over 85% of our immune cells!!! ***

  2. Next Stop Bacteria-Ville and The Recycling Factory - The Colon

    The colon is where we want our gut bacteria to live.  100 Trillion of our healthy probiotics inhabit this part of town.  They make vitamins, they make mood signaling chemicals like serotonin!  They help digest any left-over food and fibers coming through.  They help out our immune system, and they help to feed the cells of our colon!  They do more for us than anybody really understands.  Science is learning new things about our gut bacteria every day!

    Our colon also recycles water that came along on our tour as well as any left-over bile. These fluids are reabsorbed into our bodies to be used again.

  3. That brings us to the end of our tour, which you are surely very familiar with:D  

    What comes out the other end is important to monitor because it can tell you a lot about how your digestive system is working.  


I hope you enjoyed the ride and I hope that this post has taken away some of the mystery surrounding the fate of your food.  And who knows, maybe the next time you, your child or family member has an upset stomach...you might be able to use this information to help troubleshoot and find a remedy to the problem!  


Post By:  Hollie Donelson, NTP


Digestion go through steps

Brain chewing etc  lead into eating environment at home