The use of pseudo-cereals for wheat products making is to fortify the deficiency of nutritional value in wheat flour. However rich in proteins plant additives could increase acrylamide content in baked products. The present study was focused on acrylamide reduction in wheat flour biscuits supplemented with lupine and defatted flaxseed flour treated by solid state (SSF) and submerged (SMF) fermentations by Lactobacillus sakei, Pediococcus pentosaceus and Pediococcus acidilactici strains. After fermentation the decrease in asparagine was on average of 67.6 and 80.6%, and reducing sugar contents were reduced by 18 and 79.4% in flaxseed and lupine, respectively. The most effective acrylamide reduction in biscuits (78 and 85%, respectively) was reached using P. acidilactici for flaxseed (SMF) and lupine (SSF). It was found a significant effects of lupine or flaxseed addition (F(1.24) = 4032, P < 0.001), fermentation method (F(1.24) = 22,371, P < 0.001), type of microorganisms applied for the fermentation (F(2.24) = 5907, P < 0.001) and interaction of these factors (F(7.24) = 40,001, P < 0.001) on acrylamide concentration in wheat biscuits. Using L. sakei for SSF of flaxseed and SMF of lupine acrylamide was reduced on average by 83.4%. Fermented lupine and flaxseed could have potential application for production of safe and high nutritional value biscuits. •Selected lactic acid bacteria could be used for non traditional cereal fermentation.•Fermentation decreased asparagine and reducing saccharides content.•Fermented plants additives reduced acrylamide content in biscuits.•Fermented flaxseed and lupine improve biscuits acceptability and safety.