The potential for fermentation of plant extracts by probiotic bacteria has been more investigated due to the increased demand for plant-based foods by the vegan and flexitarian public. Foods containing probiotics and prebiotics are called symbiotics. The objective of this project was to optimize the fermentation by probiotic bacteria from different media formulated based on extracts of Arabica coffee pulp (ECP), jerivá almonds (EJA) and yacon flour (FrY) which is a source of inulin (agent prebiotic) through the application of a Central Composite Rotational Design (CCRD). 50 mL of different formulations were fermented with 8 logCFU/mL of Lactobacillus rhamnosus sp and Bifidobacterium longum sp at 37oC in anaerobic conditions, conducted up to pH≈4.5, in triplicate. The CCRD with two independent variables: ECP (%v/v) and FrY (%m/v), totaled 11 trials and had as response variables Total Growth (Total Growth = Final Count - Initial Count), Bifidobacterium Growth (Growth BL= Final Count - Initial Count) and Growing Lactobacilli (Growth LR = Final Count - Initial Count). ECP contents from 0 to 30%v/v and FrY from 5 to 25%m/v were tested. The results in LogUFC.mL-1 for Total Growth ranged from 4.13 to 5.12; for Growth BL from 4.05 to 5.05 and for Growth.LR from 4.31 to 5.13 indicating good cell development and adequacy to the minimum limits (all above 12 and 13 logUFC/mL) established by the Ministry of Health (> 9 logCFU/mL) to fit in probiotic foods. Such responses presented a good fit of the model at 95% confidence (p<0.05), which allowed the generation of predictive models for fermentation. The best assays were for central points, being ECP-15% and FrY-15% with good cell development, which is important in the development of a product with probiotics and that adds functionalities for human health.