To date, research has shown that Candida parapsilosis and Rhodotorula mucilaginosa, yeast commensals of the human gut microbiota, can transition into opportunistic pathogens, particularly in immunocompromised individuals, with microgravity further exacerbating their pathogenicity. Previous research supported by the Office of Undergraduate Research shows that exposure to microgravity increases antifungal resistance, one specific example being Amphotericin B. Building on these findings, this experiment aims to investigate the differential expression of virulence-related genes in Candida parapsilosis and Rhodotorula mucilaginosa isolates experiencing simulated microgravity under a Rotating Cell Culture System and those subjected to normal gravity conditions. Preliminary experimentation on colony growth and pathogenicity has revealed nearly double the growth rates in yeast cultures exposed to simulated microgravity compared to those grown under normal gravity. While the normal-gravity group exhibited a traditional growth curve featuring a prolonged lag phase followed by exponential growth, the simulated microgravity group demonstrated a delayed adaptation period but ultimately surpassed the growth of the normal-gravity cultures. This rapid growth under microgravity conditions suggests an adaptive advantage that may enhance yeast pathogenesis, increasing their potential for infection and colonization in the spaceflight environment. By examining genes associated with antimicrobial resistance and biofilm formation, such as ERG2, ALS1, and HWP1, this research seeks to elucidate the impact of simulated microgravity on yeast virulence to demonstrate significant alterations when comparing cultures grown under simulated microgravity conditions to those maintained under normal gravity, providing insights into the transcriptional regulation of virulence factors in response to the spaceflight environment.