Introduction

The origin of probiotics and their use in fermented foods such as cultured milk products is quite ancient since there is a reference to sour milk and fermented cultures as far back as the Bible. Lactic acid bacteria (LAB) had been widely and empirically used in the production of fermented foods even before Louis Pasteur discovered it in 1857 (Fig. 1). Surprisingly, the use of LAB as feed supplements goes back to pre-Christian times when fermented milk was consumed by humans (Azizpour et al. 2009; Hume 2011). The production, consumption and noted health benefi ts of yogurt were well known in Asia. Initially established in the Middle East and East Asia, this tradition of fermenting milk was spread throughout Eastern Europe and Russia by the Tartars, Huns and Mongols during their conquests. As a consequence, a wide range of fermented dairy products still exists in these regions and some popular products such as kefi r and yogurt are claimed to have originated from the Balkans and Eastern Europe (Azizpour et al. 2009; Hume 2011). Fil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Tohoku Universtiy; Japón Fil: Alvarez, Gladis Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina