Introduction. This work is devoted to the study of the effect of peroxide anion radicals in submicromol concentrations and the structural organization of the associated water phase in drinking waters, activated by physical methods on the viability of a number of microorganisms in the human gastrointestinal tract. Materials and methods. Studies were carried out using standard methods of microbiological analysis of drinking water on microorganisms of Escherichia coli 1257, Pseudomonas aeruginosa, Salmonella enteritidis 5765, Enterococcus faecalis ATCC 29212, Klebsiela pneumoniae subsp. pneumoniae ATCC 700603, Citrobacter freundii 101/57. Evaluation of changes in the physical parameters of water before and after treatment with the studied technologies was carried out using electrophysical and physical-chemical parameters (hydrogen index, redox potential, content of peroxide anion radical); structural and energy indicators (by the share of the associated water phase and the density of its distribution by energy levels). Results. The data obtained indicate the strongest stabilizing effect on the viability of microorganisms implementing ATP-phase energy metabolism to be µexerted by associates of peroxide anion radicals controlling metabolic processes and providing an extra-substrate channel for maintaining the energy function of microorganisms. We assume that catalytically active waters have a systemic regulatory effect, ensuring the maintenance of homeostasis of microorganisms. Similar regulation is also possible in the intestinal microbiota of the body to maintain or suppress the activity of competing microorganisms when a person uses biocatalytically active (in the range of concentrations of peroxide anion radicals in drinking water from 0.1 to 40 drinking water µg/L) drinking water. We assume that this will solve a number of issues related to the etiology and pathophysiology of a number of gastroenterological diseases caused by changes in the electrophysical state of the internal environment of the gastrointestinal tract, promoting the emergence and development of a competing, adapted to an environment with low electron-donor capacity, bacterial microbiota. Limitations. The data obtained as a result of the experiment on biota similar to the human intestinal microbiota are of scientific interest and research involving warm-blooded animals is necessary to continue work in this direction. Conclusion. Physically treated waters affect the growth or inhibition of intestinal biota colonies, which may be associated with the controlling role of peroxide anion radicals on intracellular metabolic processes in microorganisms

Background: Characteristics of silicon and its compounds found in water bodies and recently updated standards for their content in drinking water regulated by Russian Sanitary Rules and Norms SanPiN 2.1.4.3685–21, Hygienic standards and re- quirements for ensuring safety and/or harmlessness of environmental factors for humans, necessitate optimal and affordable methods of determination of silicon for drinking water quality control purposes. Objective: To summarize published data on the forms of silicon and methods of their quantitative determination in source and drinking water. Materials and methods: Information and analytical methods based on summarization and analysis of data of scientific papers published in 1923–2020 and cited by Scopus and RSCI international scientometric databases were applied. The search terms included silicon, drinking water, silicon compounds, and methods of quantitative determination. The initial sample consist- ed of 57 articles, of which 14 were excluded after primary screening and 43 publications compliant with selection criteria were reviewed. Results: Published data summarization has demonstrated the prevalence monomeric and dimeric species of silicic acid and soluble silicate ions in most water bodies. Conclusion: The silicomolybdic acid spectrophotometry is the method of choice for determination of silicon concentrations in source water.