Probiotics under Selective Pressure: Novel Insights and Biosafety Challenge

Area of Science:

• Microbiology and Molecular Biology
• Genomics and Bioinformatics
• Host-Microbe Interactions

Background:

• Advancements in high-resolution physicochemical techniques and omics technologies enable detailed investigation of bacterial survival mechanisms under stress.
• Research has highlighted significant genomic plasticity in bacteria and the potential for virulence evolution, impacting our understanding of bacterial defense strategies.
• A shift in focus from pathogens to commensal bacteria, widely used as probiotics, is necessitated by new findings.

Purpose of the Study:

• To explore the mechanisms of bacterial survival under various stressors, including biotic and abiotic influences.
• To investigate the genomic plasticity and potential for virulence evolution in microorganisms, particularly commensal bacteria.
• To address the knowledge gaps concerning the interactions between commensal bacteria and host organisms, and to emphasize the need for standardized probiotic safety assessments.

Main Methods:

• Integration of omics technologies (genomics, transcriptomics, etc.) with advanced physicochemical methods.
• Analysis of bacterial responses in axenic cultures, microbial communities, and complex holobiont systems.
• Comparative genomics and experimental evolution studies to assess genomic plasticity and virulence.

Main Results:

• Demonstrated high genomic plasticity in microorganisms, indicating a strong capacity for adaptation and evolution.
• Identified the potential for bacterial virulence to evolve under selective pressures, even in commensal species.
• Revealed that commensals can modulate host cell signaling, suppress innate immunity, and disrupt host homeostasis.

Conclusions:

• Comprehensive studies of commensal bacteria are essential to understand their plasticity, interactions with host regulatory networks, and potential impact on health.
• Existing knowledge on the "logic of life" of symbionts and their eukaryotic cell interactions is insufficient, potentially compromising practical applications.
• Standardization of safety assessments for probiotics is urgently needed due to the demonstrated potential for virulence evolution and host interaction modulation in commensal bacteria.