Intestinal microbiota: modern concepts of the species composition, functions and diagnostic techniques
Kozhevnikov A.A.¹, Raskina K.V.², Martynova E.Yu.², Tyakht A.V.³, Perfiliev A.V.⁴, Drapkina O.M.⁵, Sychev D.A.⁶, Fatkhutdinov I.R.⁴, Musienko S.V.³, Nikogosov D.A.³, Zhegulina I.O.⁴, Bavykina L.G.⁴, Karshieva A.V.⁴, Selezneva K.S.⁴, Alekseev D.G.^3,7, Poteshkin Yu.E.<sup>1, 4

1</sup> Russian National Research Medical University named after N.I. Pirogov, Moscow; ² First Moscow State Medical University named after I.M. Sechenov; 
³ Biomedical Holding «Atlas», Moscow; ⁴ «Atlas Medical Center», Moscow; ⁵ National Medical Research Center for Preventive Medicine, Moscow; ⁶ Russian Medical Academy of Postgraduate Education, Moscow; ⁷ Novosibirsk State National Research University

Intestinal microbiota is a community of different types of microorganisms inhabiting the human intestine. According to the latest data, the number of its representatives is not less than the number of cells in the human body, and the number of genera and species is estimated to exceed 50 and 500, respectively. In the course of an extensive study of the European (MetaHIT) and American (HMP) populations, it was found that Bacteroidetes and Firmicutes are the dominant types of microorganisms in microbiota. Currently, the concept of the intestinal microbiota enterotypesis is actively discussed. It postulates the existence of stable clusters of key bacterial genera in the human body that are not continent-specific and population-specific: they are enterotypes with the predominance of Bacteroides, Prevotella and Ruminococcus. The dominance of these or other species depends largely on the age of the individual. There is evidence that microorganisms can colonize the digestive tract of the fetus even before birth. The intestinal microbiota performs a protective function, participates in the regulation of the immune, nervous and endocrine systems, is an important participant in the digestive processes, synthesizes B and K vitamins, local antibiotics, short-chain fatty acids, plays an important role in neutralizing drugs and xenobiotics. The article briefly describes and compares the features of traditional and modern methods of microbiota research.

Key words: microbiota, precision medicine, enterotype, culture method, sequencing, polymerase chain reaction, PCR, real-time PCR, mass spectrometry, 16s rRNA, shotgun-sequencing, RT-Q-PCR.
For citation: Kozhevnikov A.A., Raskina K.V., Martynova E.Yu. et al. Intestinal microbiota: modern concepts of the species composition, functions and diagnostic techniques // RMJ. 2017. № 17. P. 1244–1247.