Digestion Part One: The Happy Tummy

Tummy smile

Since this is a blog about Tummies I guess the best place to start is to talk about how our tummies are supposed to work.


This is a huge subject and inspiration for this website so we’ll have plenty more to talk about in future posts!!  For now here’s a really basic explanation of the way our tummies are designed to work.


Digestion Starts in the Brain:

Eating. This is something that we do every day and for most people, at least 3 times a day but do you ever wonder what happens to your food once you swallow it?? Digestion is a North to South process that starts in your 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 yummy, nutrient dense, whole food, properly prepared healthy meal.  This is your mind-body connection at work!

Don’t forget to Chew!

Once you take that mouth watering bite the salivary enzymes 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 the two actions together liquefy your food into what’s called a Bolus.  The Bolus is swallowed and begins the descent south to that acid tank called your stomach.

digestive_system image

 The Acid Tank:

The pH of your stomach juices should be a rug burning pH of 1.5 – 3!  This acidic juice cocktail of hydrochloric acid, enzymes and mucus get to work breaking down proteins. This includes killing any bacterial or parasitic hitchhikers from your food and treating them just like any other protein. Combined with the churning motions of the powerful stomach muscles this Bolus is converted into an acidic paste called chyme.  Once the chyme is at the appropriate pH the signal is sent for the door to open into the next tank called the duodenum which is the entrance to your small intestines.

Hormones… in my Tummy?

It is of utmost importance that the chyme is really acidic because that acidity triggers a certain hormone to be released. This hormone tells the pancreas to send sodium bicarbonate to the mix which neutralizes the chyme so it doesn’t burn the walls of your duodenum and intestines which could otherwise cause ulceration.  The hormone also tells the pancreas to secrete enzymes for further breakdown of proteins, fats and carbs.  Without that neutralization from the bicarb, these enzymes would die off from the acid and not be able to appropriately breakdown these food particles.

In the presence of fat another hormone secreted at this stage of the process which signals your gallbladder to squeeze and release bile.  Bile is so important because it is like soap which emulsifies fats. No bile would be sort of like washing a greasy pan without dish soap.

***The same FAT induced hormone that tells your gallbladder to squeeze also signals to your brain that you’re full! ***


The goal of digestion is to break food down into its smallest nutrient components so your body can absorb them and utilize them for all the functions that keep us running!  Energy, growth, immunity, repair… Most of the nutrient absorption from your food happens in the small intestine.  There are little finger-like protrusions called villi and micro-villi lining this intestinal “tube” that grab onto nutrients and pull them into your bloodstream where they can be transported around your body for use.  The “leftovers” continue south through a special door called your ileocecal valve which separates the small intestines from the large intestines. What’s left is largely composed of fiber, bile, water and some nutrients that haven’t been absorbed yet. The fiber feeds your happy microbial friends that help you by producing vitamins and also butyric acid which nourishes the cells lining your colon.  Much of the water and bile are reabsorbed in the colon and recycled back into your body.  Any remaining nutrients are absorbed and the final product is feces which is sent out through the rectum and…well, you know the end of the story!

Importance of a Happy Tummy

This is a really basic explanation of what goes on in your tummy and I just want to stress how  important it is that this system is working properly!  Everything that goes on in your body depends on your digestive system to prepare and deliver the materials it needs to function! When this system is broken everything is affected and your quality of life will be diminished.  I know this from experience!  If your tummy is not happy…neither are you.

Keeping your digestion on track is one of the key ways a Nutritional Therapist can help you to improve your overall health.



Tummy smile


Post By: Hollie Donelson, NTP

Happy Tummies of The Lowcountry, LLC

Bluffton/Hilton Head, SC





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