For reasons linked to lifestyle, health, nutrition and sustainability, our diets are tending to change, in particular by rebalancing animal and plant sources in Western diet. This leads to the development of new food products, particularly fermented ones. Actually, fermentation can confer hedonic, hygienic and probiotic properties to fermented products. Fermented dairy products are well known, while legume-based fermented dairy analogues are less familiar. The development of legume-based fermented products requires a combination of knowledge of the raw material and of bacterial potential, in order to select bacterial strains with appropriate functions. In our study, new fermented products were developed based on milk, on plant-based analogues, and on the mixes thereof, fermented by lactic acid bacteria and/or propionic acid bacteria, selected on their capability to hydrolyze carbohydrates, proteins and on their immunomodulatory properties. By taking advantage of the functional complementarity between strains, we designed bacterial consortia capable of transforming different raw materials into functional fermented food products, with improved technofunctional and health properties. The development of such fermented products also raises the question of how positive interactions between bacteria can be promoted in order to improve the final qualities of these products.