Abstract: Single introduction of calcium acetyl acetonate at the doses of 25-50 mg/kg directly into the stomach of white rats, after 8 hours does not influence the qualitative and quantitative composition of main, additional and residual microflora of the colon contents of experimental animals. The introduction of calcium acetylacetonate at the dose of 250 mg/kg directly into the stomach of white rats after 8 hours leads to the changes of qualitative microbiota of colon contents that are characterized by the elimination of Eubacterium, Peptostreptococcus, Enterococcus bacteria from the biotope as well as its contamination with pathogenic and opportunistic enterobacteria, staphylococci, peptococci and bacteria of Clostridium species.

Intragastric administration of  calcium acetylacetonate at the dose of 250 mg/kg in white rats after 8 hours causes significant deficiency of various species of main microbiota (Bifidobacterium, Lactobacillus, Bacteroides, Escherichia bacteria), and elimination of  Eubacterium, Peptostreptococcus, Enterococcus species. Peptococcus, ClostridiumandE. ColiHlg⁺ bacteria, which contaminate the colon cavity of white rats, reach moderate population level in this biotope.