**3.1 Proved beneficial effects on the host**

Prerequisites for probiotics' efficacy are human origin, resistance transit gastric capacity to colonize survival in and adhesion, competitive exclusion of pathogens or harmful antigens to specific areas of the gastrointestinal tract, vitality, verifiable and stability conservation, production substances with antimicrobial action, exclusion of resistance transferable antibiotic. No pathogenicity and / or toxicity has ever been demonstrated on the host.
