Effect of probiotic strains of Bacillus subtilis on the growth parameters of broiler chickens and caecal microbiota

Abstract

In this paper, the probiotic properties of Bacillus subtilis GM2 and GM5 strains were studied. It is shown that the use of probiotic additives based on the spores of these bacteria leads to an increase in the live weight gain of broiler chickens by 4.16% and 10.76% relative to the control. Metagenomic analysis showed that representatives of the phylum Firmicutes (54.55%) and Bacteroidetes (30.45%), mainly represented by the families Ruminococcacea and Bacteroidaceae, predominate in the caecal microbiota of broiler chickens on day 42. It was found that a probiotic based on the B. subtilis GM5 strain leads to an increase in the proportion of Firmicutes in caecum by 27% and a decrease in Bacteroidetes by 19%. There was also a significant decrease in the number of representatives of opportunistic pathogenic bacteria of the Enterobacteriaceae family relative to the control group.