Pseudomonas aeruginosa (Pa) is the most prevalent and persistent microorganism isolated from cystic fibrosis (CF) sputum and is a leading cause of mortality in CF patients. Approximately 15% of people with CF are infected with Aspergillus fumigatus (Af), a devastating human fungal pathogen. Af can accelerate lung function decline in people with CF, and some of these Af infected patients will develop allergic bronchio-pulmonary aspergillosis, a hypersensitivity fungal lung disease. Clinical evidence suggests that the co-isolation of both Pa and Af indicates a poorer prognosis, but the exact reason for this is unclear. Using multi-omics approaches combined with reverse genetics, this work aims to understand how the physiology of both Pa and Af change in co-culture when compared to monoculture, and to dissect the specific cues which drive these physiological changes. Together, these data will begin to answer the fundamental question of how coinfecting microbes interact during polymicrobial infection.