Anaerobic fermentation of native starches from tapioca, normal and waxy corn, and their laboratory modified preparations, by selected Bifidobacterium strains (Bifidobacterium pseudolongum KSI9, Bifidobacterium breve KN14, and Bifidobacterium animalis KS20a1) was carried out under in vitro conditions. The growth and acidifying properties of bifidobacteria and utilization of resistant starches were determined in relation to glucose in the control sample. The preparations obtained from normal and waxy corn starches were the best substrates for growth of B. breve KN14, even compared with glucose. The growth of B. animalis KS20a1 was comparable, both on native and modified starches, whereas the starch preparations better stimulated the growth and acidifying activity of B. pseudolongum KSI9, as compared with native starches. The resistant starch fractions of all preparations were generally utilized to a higher degree (64-85%) compared with native starches (56-79%). The results of the study indicate that tapioca and corn starches, both native and modified, could be substrates beneficial for the enhancement of Bifidobacterium intestinal populations.