Accepted_test
The intestinal microbiota is currently considered an important factor in the pathogenesis of cancer. The purpose of this study is to determine changes in the quantitative and qualitative composition of the intestinal microbiota in Wistar rats during chemical induction of breast cancer (BC). The work was performed on female Wistar rats (n = 40) at 3 months of age, weighing 210-250 g, using culture methods for studying fecal microbiota in a group of rats, in the induction of breast cancer N-methyl-N-nitrosourea (group 1, n = 20), on the 1st (before administration of N-methyl-N-nitrosourea), 14th and 35th days of induction and in parallel in a group of intact rats (group 2, n = 20). The study showed that in all experimental animals, representatives characteristic of the intestinal normobiota of warm-blooded animals predominated, namely: Bifidobacterium spp; Lactobacillus spp; Escherichia coli with pronounced enzymatic properties; Enterococcus spp; Clostridium spp. In addition, Staphylococcus spp; yeast-like fungi of the genus Candida and mold. Escherichia coli with reduced enzymatic activity was also detected. It was established that the isolated bacteria belonged to 3 types, 4 classes, 5 orders, 6 families, 6 genera of the bacterial domain. Also, 2 genera of fungi belonging to the order Saccharomycetales were isolated. The most significant changes in the composition of the intestinal microbiota were noted in animals with chemically induced breast cancer on the 35th day tumor induction: the appearance of pathogenic microflora in the intestine was revealed.