The present invention concerns the use of lactic acid bacteria selected and fungal enzymes for the gluten complete degradation from both bread and durum wheat, barley, rye and oat flour. In particular, the invention concerns the use of lactic acid bacteria selected and fungal enzymes for the gluten complete degradation (residual gluten concentration lower than 20 ppm) of cereal flours, which after detoxification can be used according to a standardized biotechnological protocol for the production of various gluten- free foods.