Antimicrobial potential of Streptococcus salivarius as probiotic for the upper respiratory tract.

The microbiota of the upper respiratory tract (URT) is emerging as a gatekeeper to respiratory health, but it is currently underexplored at the functional level compared to other body sites. URT diseases such as otitis media (OM) form leading causes for antibiotic prescription, while the functional role of bacteria in the disease pathology is still not clear. Consequently, new insights into the functional biology and microbial ecology of OM as a microbial disease are needed to design novel therapeutic strategies. Microbiome sequencing of the URT revealed Streptococcus salivarius as one of the primary colonizers of the oral cavity shortly after birth. It is also significantly more abundant in the nasopharynx of healthy children compared to children with chronic OM. Endogenous beneficial bacteria can indeed play a pivotal role in URT health through inhibition of respiratory pathogens and immunomodulation. As a key beneficial commensal, specific strains of S. salivarius could have high potential as URT probiotics. These strains can produce secreted secondary metabolites with bacteriostatic or bactericidal activity, but their role in probiotic effects is currently underexplored. This project will focus on exploring the metabolic properties and functional potential of S. salivarius isolates, which will be evaluated through dedicated in vitro culturing systems, phenotypic screening assays and comparative genomics, combined with an innovative proof-of-concept study in humans.

Keywords:DNA ANALYSIS, SECONDARY METABOLITES, STREPTOCOCCUS SALIVARIUS

Disciplines:Bacteriology, Microbiomes, Cell, tissue and organ engineering, Cellular therapy, DNA analysis technology