in the tested commensal microorganisms, probiotics and pathogens, in target of the
animal species, and in the health status of farm or laboratory animals (Alexopoulos et al., 2004).
The appropriate results were mainly based on the assessment of data from different studies –
under more or less praxis-relevant conditions – or challenge trials measuring diarrhoea score
and length of diarrhoea after the application of the above-mentioned probiotic bacteria. Results
further depend on diverse other factors such as the initial microbiota in the host, the applied
probiotic strain that was used in the study, etc.