 In oats, β-glucan is found mainly in the endosperm of the oat kernel, especially in the outer layers of that endosperm.Enterocytes facilitate the transportation of β(1,3)-glucans and similar compounds across the intestinal cell wall into the lymph, where they begin to interact with macrophages to activate immune function.Radiolabeled studies have verified that both small and large fragments of β-glucans are found in the serum, which indicates that they are absorbed from the intestinal tract.