Assuring the continued safety of lactic acid bacteria used as probiotics

Lactic acid bacteria have long been used to improve the safety of foods through fermentation. Some fermented products were also early used for their perceived health benefits, which lead to the development of probiotics as we now know them. Probiotics mainly belong to the genera Lactobacillus and Bifidobacterium. Most members of these genera are not considered pathogens or even opportunistic pathogens. Nevertheless, rare cases of Lactobacillus and Bifidobacterium infection have been reported, possibly even associated with the consumption of probiotic products. Such cases are extremely rare and the subjects always had severe underlying conditions most often affecting the immune system. There does not seem to be any risk for the general population. Safety assessments can be performed and many possible tests exist. It is, however, not certain these tests will prevent rare case of Lactobacillus infection in certain high-risk patients. The benefits of probiotic use should be weighed against the possible small risk. Such an evaluation will, in most cases, be favourable and should therefore not discourage consumption of probiotics. Presented at the Second Probiotic Conference, Košice, 15–19 September 2004, Slovakia.