Updated project metadata. The characteristics of parasitic infections are often tied to host behavior. Although most studies have investigated definitive hosts, intermediate hosts can also play a role in shaping the distribution and accumulation of parasites. This is particularly relevant in larval stages, where intermediate host behavior could potentially interfere in the molecules secreted by the parasite into the next host during infection. To investigate this hypothesis we used a proteomic approach to analyze excretion/secretion products (ESP) from Fasciola hepatica newly excysted juveniles (NEJ) derived from two intermediate host species, Lymnaea viatrix and Pseudosuccinea columella. The two analyzed proteomes showed differences in identity, abundance, and functional classification of the proteins. Based on the differences identified between NEJ ESP samples, we can conclude that the intermediate host is a factor influencing the proteomic profile of ESP in F. hepatica