Stress-induced changes in the population of the mucosa-associated microbiota of the colon of Wistar rats and their correction with an analogue of adrenocorticotropic hormone

Objective - to study stress-induced changes in the population of the wall microbiome of the colon of wistar rats and their correction with an analog of the adrenocorticotropic hormone ACTH_6-9-PGP. Materials and methods. The experiments were performed on male Wistar rats (n = 45) weighing 280-300 g. The experimental animals were divided into 5 groups (n=9 in each): 1 - control: non-stressed rats were injected with saline solution, 2 - saline administration to stressed animals, 3-5 - administration of ACTH6-9-PGP to stressed rats in doses of 5, 50 and 500 μg/kg from the 15^th to the 28^th day of the experiment. The method of L.I. Kafarskaya and V.M. Korshunov was used to assess the state of the wall microbiota. The genus/species of the isolated microorganisms was determined on a Maldi Biotyper Microflex mass spectrometer (Bruker, USA). The relative mean and frequency of occurrence of microorganisms were evaluated. Results. 28-day restraint stress leads to the development of qualitative changes in the composition of the wall microbiota of the colon of rats in the form of a decrease in the relative average and frequency of occurrence of obligate microorganisms (Lactobacillus spp., Bifidobacterium spp., E.coli with normal enzymatic activity, Enterococcus spp.) and an increase in the proportion and frequency of opportunistic pathogens (Enterobacter spp., Proteus spp., Klebsiella spp., Morganella spp., Staphylococcus (coagulase-negative), S. aureus, Candida spp.). The use of the melanocortin analog ACTH_6-9-PGP corrected the above-mentioned stress-induced changes in the microbiological landscape of the colon. Conclusion. Thus, the synthetic analogue of melanocortins ACTH_6-9-PGP is a promising molecule for the development of pathogenetically based approaches to the correction of stress-induced disorders in the body.

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