Table 3.

Minimum criteria to appropriately use the terms ‘probiotic’, ‘prebiotic’ and ‘synbiotic’

Substance	Safe for intended use	Identity characterized	Scientifically valid name	Strain designated	Microorganism deposited in international culture collection	Mechanism of action linked to microbiota	Selective utilization of substrate		Study in target host demonstrating both:		Proper conditions of use
							By resident microbiota	By co-administered live microorganism	Health benefit	Selective utilization of substrate
Probiotic	☑	☑	☑	☑	☑	NA	NA	NA	☑	NA	☑
Prebiotic	☑	☑	☑	NA	NA	☑	☑	NA	☑	☑	☑
Synbiotic
Complementary synbiotic	☑	☑	☑	☑	☑	☑	☑	–a	☑	NR	☑
Synergistic synbiotic	☑	☑	☑	☑	☑	☑	–a	☑	☑	☑	☑

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. A prebiotic is a substrate that is selectively utilized by host microorganisms conferring a health benefit. Synbiotics are a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host. A complementary synbiotic is a mixture of a probiotic plus a prebiotic. A synergistic synbiotic is a synbiotic in which the substrate is designed to be selectively utilized by the co-administered microorganisms. A synbiotic must meet the evidence required for either complementary or synergistic synbiotics. All substances should be made available to the scientific community for validation of research findings. ^aThe intent of a synergistic synbiotic is for the substrate to support the growth and/or activity of the co-administered live microorganisms but selective utilization by the resident microbiota is not a disqualifier. The prebiotic component of a complementary synbiotic must be selectively utilized by the resident microbiota, but if it is also utilized by the co-administered probiotic, it is not a disqualifier. NA, not applicable; NR, not required.