INFLUENCE OF IONIZING RADIATION ON THE MICROFLORAOF THE SMALL INTESTINE OF RATS ON THE ISLANDAND IN THE DISTANT PERIOD

Abstract

Background. Human intestinal microbiota is defined as microorganisms (bacteria, viruses, archaea and protists) that
inhabit the mucous membrane of the intestinal tract. The microbiota is in close contact with the human body: the host
organism provides the environment and nutrients, and microorganisms protect the body from pathogens, contribute to the
normal maintenance of immunological, metabolic and motor functions.
The aim of the study was to study the effect of ionizing radiation on the small intestinal microflora of rats.
Research materials and methods: Research design - experimental. Research methods: bacteriological. The object of
study was ten-week-old white rats weighing 220 g (95% CA: 203-238) from the Kazakh Research Center for Quarantine and
Zoonotic Diseases in Almaty, belonging to the Wistar family. According to the plan of the experiment, the animals were
divided into 2 groups. The Power and Sample Size Analysis program was used to calculate the sample size. The number of
rats required for the experiment was 80. In the first study group (n = 40), rats were inhaled neutron-activated manganese
(56Mn) powder. The flux of thermal neutrons for this group was 8 × 1014 n / cm2. The second group (n = 40), ie the control
group, consisted of intact rats. The experiment was reviewed and approved by the Ethics Committee of the State Medical
University of Semey in accordance with the Directives of the European Parliament on the protection of animals used for
scientific purposes (Protocol .13.1 dated 28.11.2019).
Research results. According to the results of the study, dysbacteriosis of the intestinal microflora of experimental
animals was detected in the acute period after internal radiation in small doses, ie on the third day of the study.
Dysbacteriosis was manifested by a decrease in the amount of normal intestinal microflora bifidobacteria 5.47 (5.30; 5.47) (p
= 0.001) and Escherichia coli 5.47 (5.30; 5.47) (p = 0.001). In comparison with the control group, conditionally pathogenic
microorganisms were found to be 6.3 (3.14; 6.47) (p = 0.001), 4.3 (4.1; 4.47) (p = 0.001) and gilded staphylococci of Candida
relatives. An increase in the statistical value of 3.47 (3.30; 3.69) (p = 0.001) was detected. In groups exposed to internal
radiation (56Mn), the recovery of the intestinal microflora can be observed in the distant period. Only a twofold decrease in
the number of lactobacilli, the main beneficial representative of the normal microflora, was found. The number of lactobacilli
in the bitter intestinal microflora of internally irradiated rats decreased to 2.0 g (2.0; 2.15) (p = 0.001).
Conclusion. Small doses of internal radiation lead to disruption of the normal microflora of rats.