Probiotics are defined by the Food and Agriculture Organization and the World Health Organization as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host” (1). Lactobacillus rhamnosus Lcr35® strain, marketed as a probiotic for its anti - Candida albicans properties (2,3), is genetically and physiologically well - characterized. Moreover, ingredients included in formulations containing Lcr35®, are able to increase its probiotic effects. However, mechanisms of action of Lcr35®, as other probiotics, a re still unknown and knowledge about these mechanisms are becoming a priority today. In order to investigate the molecular mechanisms involved in the Lcr35® strain probiotic properties, in vivo studies using C. elegans have been carried out on: (i) nematode survival in presence of the probiotic strain, potentialized or not, (ii) preventive and curative effects of Lcr35® on C. elegans against C. albicans infection and (iii) transcriptomic approaches used to identify the signaling pathways and the molecular mechanisms involved in anti C. albicans effect of Lcr35®. C. albicans pathogenicity is generally related to hyphae formation, which induce host cell destruction. A recent publication (4) has shown a reduction in C. albicans pathogenicity by a preventive treatment of the worm with a Lactobacillus paracasei, but without a significant reducing of filamentation. Thereby, experiments on reduction of filamentation of C. albicans by Lcr35® will be achieved. In closing, our studies on Lcr35® curative effects against C.albicans will be the first to be performed, as there is no paper on this subject