The book will be useful to the professors, researchers as well as students to the great extent who are working in the field of probiotic lactic acid bacteria (LAB). It contains the research work carried out on LAB isolates of Traditional fermented milks. The study also highlights various in vitro tests to confirm the probiotic potential of LAB isolates. Hence, at large, the book is on 'How to test' the ability of isolates to provide functional and probiotic health benefits in laboratory conditions.