When you eat bread, rice or pasta, the food turns into a liquid while it is in your stomach, then when it reaches your intestines, the gluten sugars quickly pass through the walls of your gut and into your blood. Then your pancreas releases large amounts of insulin to make your fat cells absorb the sugars. Then within two hours, everything is finished and you feel tired because the nutrients surged into your blood in a short space of time and suddenly there is nothing.
I imagined that fragments of vegetables in the food would come between the starch and walls of your guts and get in the way of absorbtion so instead of taking 2 hours, it takes 5 hours for the gluten sugars to pass through.
You still absorb all the glutens but it is spread out over a longer time and your muscles can use it straight away. The vegetables act like fibre and remain solid all the way through so it makes the stool less sticky. You absorb nutrients from the vegetables as well but most of it passes all the way through. Sometimes I eat enough vegetables to make my poop turn green. I will have less sticky slobs for poop and more fibrous firm stools. Perhaps all my poop will be green one day.
This is the way I think at the moment. I'm not 100% sure it is the truth.