What it means is that enzymes are required to metabolize carbohydrates. Fiber, for example, cannot be broken down by any enzyme in the human body for digestion, which is why it passes through your intestines.
In this case, the manufactures claim that the composition of their product (pasta) makes the pasta act like a fiber (i.e. it passes through your intestines without being utilized for fuel/sugars) which is why it does not affect a glucose count, and hence why it is o.k. for diabetics and low carbers to eat.
If this really works, it would be a heaven send for me and anyone else who does the AD, as we would be able to eat pasta/meat dishes.