probiotics under selective pressure: novel insights and biosafety challenge

The emergence of new high-resolution physic-chemical methods, the introduction of omics technologies into the practice of biomedical research have determined new opportunities for studying the mechanisms of bacterial survival in vitro and in vivo under the pressure of biotic and abiotic stressors, in axenic cultures, microbial communities, and holobionts. innovative methodological platforms contributed to obtaining unique data relevant for both fundamental and applied science. experimental results indicating a phenomenally high level of genomic plasticity of microorganisms and the potential for the evolution of bacterial virulence under conditions of selective pressure have made significant adjustments to our understanding of the arsenal of self-defense tools in bacteria and the prioritization of research. the growing pool of factual material today dictates the need to focus attention not only on pathogens, but also on widespread commensal bacteria, which have the status of probiotics, actively used in medicine, agriculture and the food industry. reports of the possibility of large-scale genomic reorganization and progressive evolution of virulence in these bacteria under stressful conditions, means for modulation of host cell signaling systems and suppression of innate immunity, negative regulation of key cell cycle controllers, disruption of the structure of the intestinal microbiota and intestinal homeostasis reveal the obvious insufficiency of our knowledge about the &logic of life& of symbionts and the mechanisms of their interaction with eukaryotic cells, which may compromise the ideas of a number of practical applications. this determines the relevance of comprehensive studies of commensals, the potential of their plasticity in different environmental conditions as well as the ways of intercellular communication and interaction with regulatory networks of higher organisms, and dictates the need to develop a standardization for assessing the safety of probiotics.