Introduction

Abstract

Microorganisms are starters of the nascence and subsequent evolution of all biological life varieties on our planet including humans. A contemporary view of a human organism presents it as a superorganism, a dynamic symbiotic community of various prokaryotic and eukaryotic cells (Vakhitov and Sitkin 2014, Shenderov 2008, Shenderov 2014b, Ugolev 1991, Caselli et al. 2011, Dietert and Dietert 2015, Lederberg 2000). The microbial component of this community includes bacteria (which dominate), Eukarya and Archaea (up to 10^13–14 cells totally). Microbiome/microbiota (a term introduced into scientific literature by Joshua Lederberg) represents the totality of commensal, symbiotic and pathogenic microorganisms inhabiting human body (Lederberg and McCray 2001). According to the latest data, the human organism contains around 3 × 10¹³ eukaryotic cells and 3.9 × 10¹³ microorganisms colonizing human body; it means that quantitatively, the content of human cells and microorganisms is quite similar (Sender et al. 2016). As regards bacterial content, symbiotic microbiota in the digestive tract reaches its maximum in the large intestine (up to 10¹² CFU/g); this is the most densely inhabited bio-ecosystem on our planet. Human microbiota has a distinctly individual character on the genus and species levels and — especially — on the strain levels (Gilbert et al. 2016, Meisel and Grice 2017, Mimee et al. 2016, Sonnenburg and Backhed 2016).

All diseases start in the gastrointestinal tract.(Hippocrates 460–370 BC)Multiple and numerous associations of microorganisms inhabiting human gastrointestinal tract determine, to a great extent, our physical and spiritual health.(Mechnikov 1908)Microbes rule the world. We must listen closely to their language and when we learn more, we will be capable of a better and more harmonic interaction with them. The presence of active microbial compounds in the gut has physiological and pathophysiological consequences for the host.(Midtvedt 2008)