Introduction. Microbiocenosis of the mucous membranes of the respiratory tract is a powerful natural anti-infectious barrier in COVID-19. Coronavirus infection depresses the factors of natural immunity, which causes a violation of association in the microbiota. The study of this problem is especially important in the aspect of the older age category. The purpose of the work is to study the age-related features of lower respiratory microbiocenosis correlating with COVID-19 outcomes. Materials and methods: To assess age-related changes, 812 people were included in the study and three groups were identified depending on age. A total of 1,394 microorganisms were studied. Results: The microbial landscape of the respiratory tract during the study in persons with coronavirus infection before the start of treatment is represented by the following microorganisms: Streptococcus, Neisseria, Staphylococcus, Corynebacterium non diphtheriae, Enterococcus, Moraxella, Haemophilus, Pseudomonas, Acinetobacter, Escherichia, Proteus, Klebsiella, Enterobacter, Citrobacter, Stenotrophomonas, Morganella, Candida, Penicillium, Mucor. When comparing the frequency of detection of microorganisms in hospital less than 14 days with patients whose hospitalization period exceeded 15 days, it was obtained that statistically significant, in the first, Candida albicans and Corynebacterium spp were less common at p = 0.015, and Enterococcus faecalis was more common. Discussion: The composition of the microbite in the two groups was common, except for the absence of genera such as Proteus, Pseudomonas, Moraxella, Haemophilus in the group of persons whose hospital stay was more than 15 days and Morganella, which was not detected in the group of persons, the hospitalization period of less than 14 days. Conclusion: The length of hospital stay and the unfavorable outcome in coronavirus infection is characterized by the detection of colonization with more aggressive microflora upon admission, as well as a decrease in the detection of useful representatives of the commensal microbiota, which is especially pronounced among people over 60 years of age.