Benefits for oral microbiota from Streptococcus salivarius M18 as a BAS in the Dentoblis tablets (Serbia) and autoprobiotic S. salivarius strains, and their effectiveness in disbiosis prevention were compared in a 14-day hypobaria study. Dynamics of the qualitative and quantitative composition of the Streptococcus mutans pariodontal pathogenes, opportunistic oral pathogens Staphylococcus aureus, Fusobacterium spp., Candida spp., Prevotella spp., and protective oral microbiota Lactobacillus spp., was investigated before and after consumption of the commercial probiotics and autoprobiotic strains. Integral oral cavity investigation consisted of mass-spectrometry of the microbial markers and enzyme immunoassay (EIA). The best results (decreases in the quantities of S. mutans, S. aureus, Fusobacterium spp. Candida spp. and growth in Lactobacillus spp.) were gained by consumption of personified S. salivarius strains. © 2024 Slovo Ltd. All rights reserved.