Obstructive lung diseases such as cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) and asthma are characterized by impaired mucus clearance. For 60-70% of adults with CF Pseudomonas aeruginosa is the primary pathogen responsible for mortality in these patients.1 Understanding the interplay between this pathogen and mucus could lead to superior methods of drug design and delivery for the treatment of CF. In this work, we explored how P. aeruginosa affects mucus hydrogel assembly and the influence of the mucus gel on bacterial growth. Using multiple particle tracking microrheology and monitoring bacterial growth in a mucin-based we systematically examined each part of the system . We have observed that P. aeruginosa affect mucus gel assembly by prolonging the gelation process of mucin-based hydrogels. Also we found that P. aeruginosa growth in hydrogels was two times slower than P. aeruginosa grown in media. The results of this work provided a deeper understanding of how P. aeruginosa affects airway mucus in patients with cystic fibrosis.