Effect of a medium simulating vaginal fluid on the growth and expression of beneficial characteristics of potentially probiotic lactobacilli

The effectiveness of a probiotic formulation applied in human vagina depends on the possibility of adaptation of the beneficial microorganisms in this environment. The understanding of the interactions of potentially probiotic microorganisms with the vaginal fluid, which shows some specific physical and chemical properties, can help to the design of improved vaginal probiotic formulations. The aims of this paper were to design a medium simulating vaginal fluid (MSVF), and to evaluate the growth, pH modifications and expression of beneficial characteristics of potentially probiotic vaginal lactobacilli in the growth medium designed. Lactobacillus acidophilus CRL 1251 and 1266, L. gasseri CRL 1259, L. paracasei CRL 1289, L. johnsonii CRL 1294, and L. salivarius CRL 1328 were able to grow or survive in the MSVF designed. The production of inhibitory substances (lactic acid, hydrogen peroxide or bacteriocine) varied at different extent, and L. johnsonii CRL 1294 showed auto-aggregation ability under the culture condition assayed.