Bi®dobacterium spp. and Lactobacillus acidophilus: biological, biochemical, technological and therapeutical properties relevant for use as probiotics

This review focuses on the biological properties and consequent technological roles of intestinal bacteria with potential health-promoting capacities, and provides selected examples available in the literature that are pertinent to the aforementioned concepts. A comprehensive overview pertaining to the taxonomy and ecology, as well as nutritional and health e€ects of Bi®dobacterium spp. and Lactobacillus acidophilus, is provided; particular attention is paid to their incorporation, and growth and acidi®cation features in fermented dairy products. The typical poor growth of these species in milk is highlighted, and the use of bi®dogenic and growth factors, including their nature and function, is discussed. E€orts to establish optimum environmental conditions for their growth are critically reviewed, in addition to the e€ects of the food and storage conditions on microbial survival. Criteria for selection of e€ective microbial strains for their probiotic e€ect are listed, and modi®cations to improve fermentation eciency and shelf-life of ®nal dairy products are suggested; among these, the incorporation of Bi®dobacterium spp. and L. acidophilus into a solid matrix, such as cheese, is emphasized. # 1999 Elsevier Science Ltd. All rights reserved.