What are probiotics?
Dr Roy Fuller defined a probiotic as: “A preparation of viable microorganisms which is consumed by humans or other animals with the aim of inducing beneficial effects, qualitatively or quantitatively, influencing their gut microflora and/or modifying their immune status.” (Fuller, 2004). This definition emphasises the importance of viable living cells as essential components of probiotics.
The word probiosis originated from the Greek pro (for) and biosis (life), and is therefore opposite in meaning to antibiosis, which promotes the proliferation of bacterial species within the gastrointestinal tract. Probiosis is defined as 'the property of the normal adult flora to resist the overgrowth of component strains and the establishment of foreign strains’ and is reinforced or re-established by probiotics. The concept of probiotics applied to preventative medicine is claimed to have originated from Eli Metchnikoff. He postulated that the longevity observed in the Balkan people was due to the regular consumption of soured milk containing Lactobacillus bulgaricus.