ABSTRACT
Contents 21.1 Probiotics Past and Future .............................................................................................. 423 21.2 Unequivocal Identification ............................................................................................ 425 21.3 Enterococci as Probiotics ................................................................................................ 426 21.4 Spore-Forming Probiotics ............................................................................................... 427 21.5 Probiotics in Animals .................................................................................................... 428 21.6 Probiotics and Infection ................................................................................................. 429 21.7 Antibiotic Resistance ...................................................................................................... 430 21.8 Clinical Studies ...............................................................................................................431 21.9 Epidemiological Surveillance.......................................................................................... 432 21.10 How Can We Compare Probiotics? .............................................................................. 432 21.11 Evolution of Guidelines for Probiotic Safety ................................................................ 433 21.12 Safety Considerations in Summary ...............................................................................435 References ............................................................................................................................... 436
Probiotic organisms are commonly from the genera Lactobacillus and Bifidobacterium, strains of Enterococcus and Saccharomyces species being among the exceptions. Members of these genera are generally regarded as safe because they have a long history of use. They have been associated with disease only rarely, usually as opportunistic infections in people with predisposing conditions (Donohue et al. 1998; Ouwehand and Salminen 2003; Lahtinen et al. 2009). A recent study, conducted with the probiotic strain Escherichia coli Nissle 1917, has shown that host-related factors may play a key role on the safety of probiotic strains (Gronbach et al. 2010).
