The objective of this study was to determine the production of mammalian lignans such as enterolactone and enterodiol from ten cereal products (bran and flour), ten berries and ten vegetables by using the technique of in vitro fermentation with human fecal microbiota and to compare with the production of these lignans from flaxseed. Results showed a wide range (78.3 to 321.9 nmol/g) in the amount of mammalian lignans produces from cereal. Cereal brans were the highest producers of mammalian lignans (294.1 to 321.9 nmol/g). The lignan production from bran was 2.2 to 2.3 times higher than that from whole flour of the same kind of cereals. From berries the production of mammalian lignans ranged from 7.8 to 382.8 nmol/g depending on the product type. Cloudberries, raspberries and strawberries produced the higher amounts of mammalian lignans. The vegetables as compared to cereals and berriers produced the lower concentration of mammalian lignans (10.5 to 91.2 nmol/g) and potatoes among them were the higher producer. The study showed that cereal bran, especially rye bran, also some kind of berries (raspberries, strawberries, and cloudberries) could be an important source of these bioactive compounds. The data should be useful in the estimation of mammalian lignan production from a given diet and in the formulation of high lignan producing diet for the purpose of reducing the cancer risk.