For example, sesame seeds are nutritious and contain lots of minerals,
http://nutritiondata...products/3070/2
But if you see undigested seeds in stool, does that mean no nutrients were absorbed?
From the evolutionary point of view, seeds evolved as a reproductive strategy for plants. They pass through the GI tract of mammals, get excreted, and get spread across new geographic areas, which allows plants to survive.
But if that's the case than seeds are unabsorbed. The popular advice that seeds are healthy and nutritious would seem to be wrong, they aren't digested.