The article presents data on the use of modern methods of analysis, isolation and identification of representatives of the microbiocenosis of the ceca of the intestines of industrial pigs raised using intensive technology. Bacterial metagenomic analysis was used to study the composition of microflora of various taxonomic groups in the chyme of industrial pigs. Classical microbiological research methods were used to isolate the dominant representatives of the genus Lactobacillus. Identification of the probiotically relevant microbial cultures was performed by mass spectrometric analysis using MALDI-ToF MS in a BactoSCREEN spectrometer, as well as by nucleotide sequencing of the 16S rRNA gene. Full-genome sequencing of isolated dominant pure cultures of the genus Lactobacillus was carried out. As a result of the research, it was found that in the cecum of the intestines of suckling piglets, growing and fattening pigs there is a diversity of microbial communities, which changes in quantitative proportions with age. The results of mass spectrometric analysis revealed the presence of protein spectra of important representatives of bacteria of the genus Lactobacillus, among which two species, Lactobacillus amylovorus and Limosilactobacillus mucosae, were dominant, which were additionally confirmed by analyzing their nucleotide sequence of the 16S rRNA gene and by performing full-genome sequencing.