Healing Hypothesis

Health begins in the gut

how digestion works

I’ve started thinking that our bodies are really tissues surrounding the tube that is the GI tract, where the tissues extract what they need to survive out of the tube.

And we call ourselves the host. The biological definition of a host is an organism that harbors a parasitic, mutual, or commensal symbiont, typically providing nourishment and/or shelter to what is being harbored. I can’t help but think that our GI tracts are actually the host, and we are the mutual or commensal (maybe even parasitic) harbored part of this equation. Chew on that (pun intended) for a minute!

I want to elaborate on how digestion works and what is supposed to happen, which allows us to survive.

Digestion begins in the mouth, the entry point of the digestive tract. This sounds silly to mention, however I can’t tell you how often I have to remind people of this. Chew! Step one in digestion is adequately chewing your food, and is known as mechanical digestion.

We chew our food to break it down into smaller particles so that enzymes in the mouth can start chemically breaking down and extracting what will end up as fuel for our cells to transform into energy that makes your body function. Talk about a mouthful!

As we chew, the protein, carbs and fats in the food stimulate the release of enzymes that get secreted throughout the digestive tract. In your mouth, salivary amylase starts breaking down carbohydrates into glucose molecules.

Salivary lipase is also secreted in your mouth and it accumulates in the stomach between meals. This enzyme helps digest fat.

After you chew your food and your salivary enzymes start breaking things down, you are ready to swallow, and the food moves down your esophagus and into your stomach. At this stage, salivary amylase stops working, and enzymes in your stomach start.

Pepsin, an enzyme that breaks down dietary protein into amino acids, is secreted when food reaches your stomach. FYI, there are a range of mechanisms at play that prevent enzymes from digesting the tissues that line your GI tract, this is important otherwise the enzymes would essentially digest you!

In your stomach, the food is churned around with the enzymes and your stomach acid to break down proteins. Next, this mix of food, enzymes and acid enters via the pyloric sphincter (a valve that separates the stomach from the intestines) into your small intestines.

In the small intestines, the food (now partially digested) is mixed with bile and ‘juice’ from your pancreas. Bile is made in your liver and stored in your gallbladder. It is absolutely necessary for the digestion of fats. Do not let your doctor convince you that your gallbladder is not important, and if you’ve had your gallbladder removed, you absolutely need to supplement with bile so that you can digest and absorb fats from your diet. Without the ability to digest and absorb fats, you will become deficient in fat-soluble vitamins, including A, D, E and K. I digress. Your pancreas releases enzymes that continue to digest proteins, carbohydrates, and fats into smaller particles that will subsequently be absorbed into your body so that they can be used to make your body run.

The absorption of essentially all of the nutrients needed for your body to function occurs through the lining of the small intestines. This includes fats, carbs, proteins (in their smallest, digested forms) and vitamins and minerals.

At this stage, you can see the intricate process involved in digestion, and what needs to happen so that you can extract nutrients from the foods you eat. And this is a simplified version of the process! If any one of these steps isn’t functioning at 100%, Houston, we have a problem.

What doesn’t get digested and absorbed in the small intestines is pushed into the large intestine, your colon. Here, water gets reabsorbed and what’s left is concentrated into poop. The fiber you eat ends up in your colon too. This is a very important point, ready? Fiber isn’t digested by us, which is why it lands in the colon. Fiber is digested by healthy bacteria in your colon, and this bacteria turns the fiber into what’s called short chain fatty acids (SCFAs). SCFAs are integral for gut health, and overall health. Research links low levels of SCFAs to a variety of health conditions including colon cancer, and even to skin conditions. Bacteria in your colon also make some vitamin K and biotin.

By the way, your appendix, which is found where your small intestine meets your large intestine, plays a role in immunity. It’s not useless as conventional medicine leads us to believe. When it is infected and inflamed, we need to ask why, and what is happening with your immune system that’s causing this to occur. The same goes for your tonsils and adenoids.

Next time, we’ll discuss what happens when digestion is impaired.

You can schedule a free 15 minute consultation with me to learn more, click here to get on my calendar! I can’t wait to talk to you!

Remember that at any time, if you have questions for me, contact me. It’s literally me on the other end of this technology, waiting to hear from you to learn what I can do to support you on your health journey.  

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Your partner in health,
Jennifer, MPH, MS, CNS
Functional and Clinical Nutritionist