CONICET | Buscador de Institutos y Recursos Humanos

Beneﬁcial effects of prebiotics like inulin and fructo-oligosaccharides (FOS) have been proven in health and nutrition. Yacon, an Andean crop, contains FOS (5070% of its dry weight) and, therefore, is considered a prebiotic. Commercial FOS can up-regulate total secretory IgA (S-IgA) in infant mice, prevent infection with Salmonella in swine or enhance immune response for Salmonella vaccine in mouse model. Previously, we found that administration of yacon root starch regulates gut microbiota balance and has immunomodulatory effects without inﬂammatory responses. The aim of the present paper is to analyse if yacon prevents enteric infection caused by a strain o Salmonella enteritidis serovar Typhimurium (S. Typhimurium) in a mouse model. BALB/c mice were supplemented with yacon starch (45 d), challenged with S. Typhimurium and killed to study pathogen translocation, total and speciﬁc IgA production by ELISA, presence of IgA and other cytokines and TLR4 and CD206 receptors þcells by immunoﬂuorescence and histological changes. Yacon starch admin istration had a protective effect from 15 to 30 d of treatment. We found a peak of total S-IgA production without translocation of the patho gen for these periods. At 30 d, there was an increase in IL-6 and macrophage inﬂammatory proteins-1aþ cells and expression of the receptors CD206 and TLR4. Yacon starch did not have incidence in pathogen-speciﬁc S-IgA production. Longer periods (45 d) of admin istration had no protective effect. Therefore, yacon can prevent enteric infection caused by S. Typhimurium when given up to 30 d; this effect would be mediated by enhancing non-speciﬁc immunity, such as total S-IgA, that improves the immunological intestinal barrier.