MOLECULAR MECHANISM UNDERLINES THE IMPORTANCE OF PROBIOTIC BACILLUS SUBTILIS TO ELIMINATE PNEUMOCOCCAL PATHOGEN
Probiotic nutrition is frequently claimed to improve human health. In particular, live probiotic bacteria obtained with food are thought to reduce pneumococcal colonization by pathogens in nasopharynx, and thus to reduce susceptibility to infection. However, the mechanism underlying these effects remain poorly understood.
Nasal samples were collected from 150 patients with expected Pneumococcal infection. Microbiome and growth inhibition analysis were done followed by fengycin purification. Bacillus lipopeptide was performed by RP-HPLC/ESI-MS followed by mouse colonization model.
Here we report that the consumption of probiotic Bacillus subtilis comprehensively abolished colonization by the dangerous pathogen Streptococcus pneumoniae in a rural Pakistani population. Widespread class of Bacillus lipopeptides, the fengycins, eliminates S. pneumoniae by inhibiting S. aureus quorum sensing. Our study presents a detailed molecular mechanism that underlines the importance of probiotic nutrition in reducing infectious disease. The biological significance of probiotic bacterial interference in humans, displayed that such interference can be achieved by blocking a pathogen’s signalling system.
Our findings suggest a probiotic-based method for S. pneumoniae decolonization and new ways to fight S. pneumoniae infections.