Identification of oleic acid-induced transcriptome changes under anaerobic conditions in the yeast Candida albicans

Dietary components influence microbial composition in the digestive tract. Although often viewed as energy sources, dietary components are likely to shape microbial determinants of intestinal colonization beyond metabolism. Here, we report that a dietary long-chain fatty acid enhances the yeast Candida albicans colonization of the murine gut partly by eliciting modifications to the fungal cell surface. Mice fed an oleic acid-rich diet were readily colonized by C. albicans and exhibited higher fungal load in feces compared to rodents fed an isocaloric control diet. Surprisingly, β-oxidation, a catabolic process to break down fatty acids for energy production, was dispensable for C. albicans to colonize the high-oleic acid diet-fed mice. RNA-Seq was employed to identify oleic acid-induced transcriptome changes under anaerobic conditions. We identified SOK1 as an oleic acid-induced kinase that dictates cell wall mannan exposure and binding to intestinal mucin under anaerobic conditions. Furthermore, oleic acid induced the expression of several C. albicans transcription factors that positively regulate intestinal colonization via remodeling of the fungal cell surface. Comparison of the transcriptome of the Candida albicans strain AHY940 (= WT) in YNB either with final concentration of 0.2% oleic acid (OE) or 0.02% glucose (dextrose, DX). The strains were grown anerobically at 30°C for 24 hours. RNA purification was performed from cells harvested from liquid cultures. Directional mRNA library preparation (with poly A enrichment) and sequencing using NovaSeq PE150 mode was executed at Novogene Corporation Inc.