Comparative characteristics of the composition of microbial associations of the gastrointestinal tract in humans in the norm and during dysbiosis

Abstract

The causes of the imbalance of the microbiota of the human body, in particular the intestines, are diverse: they include changes in environmental conditions, inappropriate nutrition and the use of harmful products, acute intestinal infections, chronic diseases and dysfunction of the gastrointestinal tract, the widespread use of antibiotics, reduced immunological reactivity of the organism, etc. Dysbiosis is accompanied by an increase of the detection frequency and quantity of opportunistic microorganisms. Such changes are characterized by negative consequences that can provoke the development of a number of complications of the functioning of various systems and organs of the human body. If significant deviations of the composition of the microflora compared to the state of the norm take place, it is absolutely necessary to correct it, which is possible with the use of preparations based on microbial cultures – probiotics. However, the mechanisms of antagonistic relationships between representatives of opportunistic microflora and normal non-pathogenic flora from different ecotopes of the macroorganism have not been completely studied. At the same time, it is known that the development of various forms of infectious processes, both acute and chronic, depends on the manifestation of pathogenicity and the persistence of a potential pathogen. Important for the correction of dysbiotic states is knowledge of the microbiota composition characteristics, including the formation of associations by individual of microorganisms in the associations, which in each case requires the development of individual approaches to therapy. In view of this, the aim of our research was to analyze the frequency of detection of opportunistic microorganisms and their associations in people with dysbiosis of gastrointestinal tract. As a result of our studies on the composition of the microflora of the gastrointestinal tract, in the contingent of the surveyed persons dysbiosis was confirmed for 56 (77.8%) individuals. It was determined that during normobiosis the formation of the following associations was typical: triple and five-membered 25.0%, six-membered – 18.8%, and most numerous-four membered associations – 31.3%. Of these, bacterial associations were determined in 87.5% of cases, bacterial-fungi associations – in 12.5%. During dysbiosis of the gastrointestinal tract, the following groups of microorganisms were isolated: Staphylococcus – 87.5%, Citrobacter – 64.3%, Klebsiella – 51.8%, Streptococcus – 50.0%, Serratia – 25%, Candida – 21.4%, and Hafnia – 5.4%, which were the part of the associations: six members – 37.5%, four members constituted – 25.0%, five members – 21.4%,three members – 14.3%, and a double association – 1.8%. Bacterial associations were determined in 78.6% of cases, bacterial-fungi associations – in 21.4%.