This book describes in detail the background information on food and beverage fermentation, significance of microflora of fermented products, importance of fermentation and its safety implication, overview of Ethiopian fermented products and their grouping, brief taxonomy of lactic acid bacteria (LAB), probiotics and starter cultures. It states in depth the isolation, selection and characterization of probiotic LAB from different fermented products. It summarizes the procedure of preparation of fermented products considered in the study. It explains the primary in vitro and in vivo probiotic LAB testing and selection. The evaluation of the antagonism of selected pure and mixed LAB starter cultures against known foodborne pathogens during the course of fermentation process and storage at various conditions of different products well explained and discussed.