Why are we on fire? Gluten inside out.
In this article I aim to bring to surface some truths and studies about gluten - from the inside (of out bodies) and out (in the environment). How do we digest it, what it does in our bodies, what are the symptoms of gluten sensitivities? How are gluten-containing grains processed, and why does it matter to us? We will cover quite some anatomy&physiology here, but I find it important to truly understand what is happing inside our bodies after gluten consumption. Let's begin!
What is gluten?
Gluten is an elastic protein, a string of amino-acids. Imagine a pearl necklace - each of these pearls is an amino-acid. A few amino-acids stringed and clumped together, that is a peptide. A few peptides form a protein.
An amino-acid is the only form of a molecule which our body can recognise as fuel = food for the cells. That means, the protein has to be fully broken down in the digestive tract, in order to be further used by the body for building, fuel, repair and other bodily processes.
Gluten protein makes 90% of protein in wheat, and it's located in the endosperm of the grain - so the part that contains the most carbohydrates, proteins, and very little vitamins and minerals. It is made equally out of gliadin and glutenin peptides. It's the gliadin peptide which is resistant to being broken down in the gut.
Other two parts of the grain are the bran, which is the tough outer layer protecting the kernel, and the germ, which is the embryo of the seed. These parts are full of fiber, B vitamins, minerals, fatty acids, phytonutrients and antioxidants.
These two parts (bran and germ) are also what is removed in making flour. The removal of those fats, vitamins and minerals, is what turns the grain from complex to simple carbohydrates. You can read more on the effect of consuming complex vs. simple carbohydrates in my article on blood sugar here.
Gluten is also a glue, making the dough sticky, and sometimes used in producing industrial glues, as well as the glue on some envelopes! And then imagine, what this gluey structure can do inside your intestines.
Yeah exactly, what? Let's explore what happens during the digestion of gluten (in a functioning gastrointestinal tract).
Digestion of gluten
After gluten gets swallowed, it makes its way to the stomach for further processing.
As it is a protein, the stomach has to be plenty acidic to digest it properly, because it is the hydrochloric acid which does that initial job of breaking up the protein into peptides. In the contrary to what most people think, hyperacidity of the stomach is very rare. Most people who suffer from reflux, indigestion etc, have too little of the stomach acid, for many different reasons. That means, they break down proteins insufficiently.
From the stomach, the gliadin and glutenin peptides enter into the small intestine - the part of the digestive tract, where most digestion and nutrient assimilation happens. Present in there are enzymes (also proteins) which facilitate the breakdown of those peptide bonds, so that we can get to those juicy, powerful amino-acids. Imagine those enzymes as scissors, cutting those bonds between the proteins and peptides, making them smaller and smaller. At the wall of that intestinal lining, there is another set of enzymes, facilitating that final breakdown of peptides into amino-acids for delivery into the bloodstream. Remember, only the amino-acids can be used by the cells of the body!
How does food cross from the intestines to the bloodstream?
The small intestine is a bit like a shag rug - it is lined with millions of these tiny finger-like projections, called villi, which really increase the absorption surface.