Probiotic-based nanoparticles for targeted microbiota modulation and immune restoration in bacterial pneumonia.

Area of Science:

• Microbiology
• Immunology
• Nanotechnology

Background:

• Bacterial pneumonia treatment often focuses on pathogen eradication, but restoring host immunity is crucial for effective recovery, especially in immunocompetent and immunocompromised individuals.
• Current strategies lack methods to restore host immunity in complex pneumonia cases.

Purpose of the Study:

• To develop and evaluate probiotic-based nanoparticles (OASCLR) as a novel therapeutic strategy for bacterial pneumonia.
• To investigate OASCLR's efficacy in combating pathogens, modulating lung microbiota, and restoring host immune function in different pneumonia models.

Main Methods:

• OASCLR nanoparticles were synthesized by coating living Lactobacillus rhamnosus with chitosan, hyaluronic acid, and ononin.
• Antibacterial efficacy was assessed against common clinical pathogens.
• Lung microbiota modulation was analyzed, alongside macrophage targeting via CD44 interaction.
• Macrophage phagocytic ability was quantified in immunocompromised models.

Main Results:

• OASCLR demonstrated high antibacterial efficiency (>99.97%) against various pathogens.
• OASCLR modulated lung microbiota, increasing richness and diversity by reducing pathogens and increasing beneficial bacteria.
• OASCLR targeted inflammatory macrophages via CD44, alleviating overactive immune responses in hyperactive pneumonia.
• In immunocompromised pneumonia, OASCLR significantly enhanced macrophage phagocytic ability (from 2.61% to 12.3%) by upregulating key gene expressions.

Conclusions:

• OASCLR nanoparticles represent a promising therapeutic approach for bacterial pneumonia.
• This strategy effectively addresses both pathogen burden and host immune dysregulation in hyperactive and immunocompromised pneumonia.
• OASCLR offers a potential solution for restoring immune function and improving patient outcomes in complex pneumonia cases.