Most intestinal microbes require carbohydrates for energy.
The SCD works by severely limiting the availability of carbohydrates to intestinal microbes. When carbohydrates are not digested, they are not absorbed. They remain in the intestinal tract, thus encouraging microbes to multiply by providing food for them. This can lead to the formation of acids and toxins which can injure the small intestine. Once bacteria multiply within the small intestine, they can destroy the enzymes on the intestinal cell surface, preventing carbohydrate digestion and absorption.