Significance of the normal microflora for maintenance of the gastrointestinal tract microbiocenosis
In 1681 Antonie van Leeuwenhoek, a Dutch researcher, informed for the first time about his study of the bacteria and other microorganisms revealed in the human fecal matter and hypothesized on coexistence of different bacteria in the gastrointestinal tract (GIT). Much later, in 1850 Louis Pasteur developed the conception of functional role of bacteria in the fermentation process. Robert Koch, a German doctor, conducted this research work further and developed the pure culture picking method to identify the specific bacterial strains required for differentiation of disease-inducing and beneficial microorganisms. In 1888 Ilya I. Mechnikov working at Louis Pasteur Institute gave substantiation to the theory that the complex or microorganisms inhibiting the human intestines produce “the auto-intoxication effect” on the organism, he believed that the healthy bacteria, when introduced into the gastrointestinal tract, would be able to modify the intestinal microflora action and resist intoxication.
The microflora present on the skin and mucous membranes of the open cavities incorporates tens and hundreds of different species of microorganisms. The alimentary tract represents an open system where the microorganism makes a contact with the ambient environment and microbes present in it. The normal intestinal microflora is necessary for maintaining at the optimal level the metabolic processes proceeding in the macroorganism and for provision of the high colonization resistance of the host organism in relation to the pathogenic microbes.
The normal intestinal microflora consists of the strictly anaerobic bacteria to the extent of 92-95%. The content of aerobes and facultative anaerobes ranges between 2 and 5%. The intestinal microflora content is adequately individual but the quantitative relationship of difference microbe populations is characterized by definite stability. Changes of living conditions of the host organism may involved changes in composition and population of the intestinal microflora, which is not always ignored by the macroorganism.