In recent years, due to the widespread introduction of molecular genetic methods for the study of the intestinal microbiome and the proof of its role in the development of many socially significant diseases, strategies for influencing human health by correcting the microbiota and its functions have become especially in demand. For this purpose, probiotics are commonly used, which are living microorganisms that improve the health of the host. They have certain indications and, in general, good tolerability. But extremely rarely, their reception can be complicated by the development of bacteremia, especially in immunocompromissive patients. The condition for the preservation of live functionally active bacteria is not always achievable. This prompts the search for possibilities for the use of non-living bacterial cells, called paraprobiotics, or components of microbial cells and their metabolites - postbiotics. Studies show that paraprobiotics in terms of effects on the immune system and intestinal barrier are not inferior to the effect of probiotic, but are better and safe. Postbiotics also approach the action of probiotics in many respects and are more stable. However, optimal technologies for the production of paraprobiotics and postbiotics, as well as indications for them, have not yet been clearly developed. This requires further research.