Immuno-modulating effect of the probiotic yeast Saccharomyces boulardii in infections.



The intestinal microbiota plays a vital role in the proper functioning of the immune system, which has “learned” to differentiate beneficial bacteria from pathogenic bacteria. This recognition involves cells of the innate immune system, specifically macrophages present in the lamina propria that express CX3CR1.

In this context, this project studies the immuno-modulatory effect of a probiotic medicinal yeast Saccharomyces boulardii and its interactions with monocyte cells (macrophages, dendritic cells) of the lamina propria in a mouse model infected with Salmonella typhimurium.

Administration of S. boulardii before infection induces infiltration of the lamina propria by Ly6Chi monocytes which are at the origin of macrophages expressing CX3CR1+. The results also show that S. boulardii treatment induces the expansion of Ly6Chi monocytes in blood and bone marrow of mice and thus participates in the reconstitution of CX3CR1+ macrophages in the lamina propria. The project wants to understand how S. boulardii affects these monocyte cell subpopulations. For this, they will determine which "Pattern Recognition Receptors" (PRRs) expressed by monocyte cells are responsible for the effect of S. boulardii, how these PRRs are modulated by S. boulardii and how, via these receptors, S. boulardii affects differentiation and immune function of monocytic cells in an inflammatory or infectious context.

This project is the result of the joint work between the Laboratory of Molecular PhysioMedicine (LP2M) of the University Côte d'Azur and the Scientific Center of Monaco (CSM).

Teams involved in the "Probiotic Yeast" project: 

CSM: Team "Immunity and Ecossystems": Dorota Czerucka and Rodolphe Pontier-Bres
LP2M: Team “Osteoimmunology and Inflammation”: Claudine Blin; Abdelilah Wakkach; Lidia Ibanez (PhD student).