Introduction
Interest in the role of probiotics for human health
goes back at least as far as 1908 when Metchnikoff
suggested that man should consume milk fermented
with lactobacilli to prolong life (Hughes a Hoover,
1991; O’Sullivan, Thornton, Sullivan, a Collins, 1992).
It is only recently, however, that the interrelationship
between intestinal microorganisms and the health
benefits deriving from it are beginning to be understood.
At present it is generally recognised that an optimum
‘balance’ in microbial population in our digestive tract is
associated with good nutrition and health (Rybka a
Kailasapathy, 1995). The microorganisms primarily
associated with this balance are lactobacilli and bifidobacteria.
Factors that negatively influence the interaction
between intestinal microorganisms, such as stress
and diet, lead to detrimental effects in health. Increasing
evidence indicates that consumption of ‘probiotic’
microorganisms can help maintain such a favourable
microbial profile and results in several therapeutic
benefits. In recent years probiotic bacteria have increasingly
been incorporated into foods as dietary adjuncts.
One of the most popular dairy products for the delivery
of viable Lactobacillus acidophilus and Bifidobacterium