Programming Probiotics: Diet-responsive gene expression and colonization control in engineeredS. boulardii

Abstract

Saccharomyces boulardii(Sb) is an emerging probiotic chassis for delivering biomolecules to the mammalian gut, offering unique advantages as the only eukaryotic probiotic. However, precise control over gene expression and gut residence time inSbhave remained challenging. To address this, we developed five ligand-responsive gene expression systems and repaired galactose metabolism inSb, enabling inducible gene expression in this strain. Engineering these systems allowed us to construct AND logic gates, control the surface display of proteins, and turn on protein production in the mouse gut in response to a dietary sugar. Additionally, repairing galactose metabolism expandedSb’s habitat within the intestines and resulted in galactose-responsive control over gut residence time. This work opens new avenues for precise dosing of therapeutics bySbvia control over itsin vivogene expression levels and localization within the gastrointestinal tract.