Abstract
This study delved into the underexplored psychobiotic potential of yeasts, systematically evaluating their gastrointestinal resilience and metabolic versatility in response to diverse carbon, nitrogen, and phenolic substrates. Among ten yeast strains screened, Wickerhamomyces anomalus GY4, Lachancea fermentati 9Y, and Saccharomyces cerevisiae KFAY3 demonstrated the highest gastrointestinal resistance and were selected. These strains exhibited strong auto-aggregation and hydrophobicity properties, essential traits for gut colonization. Phenomic analyses unveiled distinct metabolic fingerprints, with each strain demonstrating unique carbon and nitrogen utilization profiles, indicative of specialized functional pathways. Notably, W. anomalus significantly outperformed others in the production of short-chain fatty acids and gamma-aminobutyric acid (GABA), key metabolites linked to gut-brain axis modulation. Additionally, all strains effectively metabolized phenolic compounds in a strawberry-based matrix, significantly enhancing the bioavailability of metabolites with potential neuroprotective properties. Collectively, these findings illuminate the promising role of yeast as psychobiotic agents, offering a compelling avenue for the development of yeast-based therapeutic interventions targeting gut-brain axis regulation and mental health.