Foreign Mucins Alter the Properties of Reconstituted Gastric Mucus

During the course of evolution, distinct mucin subtypes have evolved, that predominantly occur in specific mucus variants of the body. A loss of this clear regional assignment is often associated with pathophysiological conditions such as asthma or gastric cancer. We here reconstitute mucus from different mucin subtypes to elucidate the influence of MUC5B/MUC2 contaminations on physiologically relevant properties of acidic MUC5AC gels as found in the stomach. Our findings indicate that these properties may be critically altered by the presence of an atypical mucin species. A weak integration of a contaminating mucin subtype into the host network yields weak viscoelastic gels with increased barrier capabilities. Unravelling the complex properties of mucosal barriers under disease conditions is crucial for the understanding of mucosal disease progression and for developing drug-carriers to traverse this biological barrier. Here, our results provide useful insights into mechanistic principles governing the physical properties of gastro-intestinal mucus.