Propionibacteria and bifidobacteria are bacterial genera belonging to the class of Actinobacteria that contains high G+C content Gram-positive bacteria. Dairy propionibacteria are hardy bacteria that produce vitamin B12. Propionibacterium freudenreichii is Generally Recognized as Safe (GRAS) for use as a ripening culture to manufacture Swiss-type cheese and is involved in the formation of the typical aroma and holes of Swiss cheeses. Propionibacteria can also be used in fermented foods to obtain products naturally enriched in vitamins or other health-promoting compounds whereas dairy-related bifidobacteria are mainly added to dairy products as probiotics. The selection criteria for dairy applications include high survival rate during biomass cultivation and food processing as well as desirable metabolic activity and sensory qualities. As probiotics, dairy propionibacteria and bifidobacteria must remain viable and survive during both food processing and subsequent passage through the gastric barrier. Unlike bifidobacteria, propionibacteria are not considered normal commensal inhabitants of the human digestive tract, but both they generally have low constitutive tolerance to gastrointestinal acids and bile salts. Capsular and extra polysaccharides production could increase their resistance to environmental stress conditions from production to consumption. In addition, incorporating exopolysaccharide-producing bacteria may provide technological and health advantages. Of dairy bifidobacteria, Bifidobacterium