Effect of Lactobacillus casei and yogurt administration on prevention of Pseudomonas aeruginosa infection in young mice

Pseudomonas aeruginosa is an opportunistic pathogen that rarely causes pulm onary disease in normal hosts but one that is an important cause of acute p neumonia in immunocompromised patients, including neonates, and of chronic pneumonia in patients with cystic fibrosis. The aim of this work was to stu dy the effect of oral administration of Lactobacillus casei and yogurt on p revention of P. aeruginosa lung infection in young mice (3 weeks old). This study demonstrates that oral administration of L. casei or yogurt to young mice enhanced lung clearance of P. aeruginosa and phagocytic activity of a lveolar macrophages through a dose-dependent effect. There were, however, n o significant differences in white blood cell (WBC) differential counts. Fu rthermore, it was observed that previous administration of L. casei or yogu rt induced a significant increase in IgA and IgM levels in bronchoalveolar lavages (BALs) after a P. aeruginosa infection, although there was no relat ionship with the serum values.