2.5 DESIRABLE P CHARACTERISTICs 1.5 Ideally, a microorganism should meet a predefined criteria in order to be number of considered as probiotic(see Table 2.1) strains of human origin are most suitable because some health-promoting benefits may be species specific, and microorgan- isms may in species from which they were isolated. However, it is perform optimally the not the source of the microorganism, that is the specificity of the action. recognized as being most important when selecting probiotic strains for particular applications. Probiotic microorganisms must be proven to be safe and efficacious in humans, following specific protocols for their isolation. Adherent probiotic strains are desirable because they have a greater chance of becoming established in the GIT. thus enhancing their probiotic effect. All probiotic strains should have generally recognized as safe(GRAS) status, be nonpathogenic. and cause no adverse health effects to the recipient. Probiotic microorganisms should also be technologically suitable for incorpo- ration into food products, such that they retain both viability and efficacy in that in H(nn a rommercial scale) through to and following consumption.