Antimicrobial features of probiotic formulations

WHO/FAO defined probiotics as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host” 1. The International Scientific Association for Prebiotics and Probiotics pointed out that most probiotic strains share “core benefits” linked to their metabolic activities, antimicrobial and immunomodulatory properties2. Despite being marketed for their activities, probiotics are currently commercialized as “number of live cells” and there are no other quality parameters to guarantee the functionality of the products. Aim: Developing laboratory protocols and guidelines suitable to evaluate the functional activity of commercialized probiotics. In particular, the barrier effect of the samples is investigated testing their antimicrobial activity against the principal pathogens of the gastrointestinal tract (Escherichia coli ETEC H10407, Salmonella choleraesuis serovar typhimurium, Yersinia enterocolitica).