In the article new line of research - infectious symbiology that studies interaction of microsymbionts with the host in case of infection under the conditions of their biocommunicative interrelations is discussed. The presence of interrelation of intestinal microbiota with human homeostasis disorders postulates thesis that: human organism is superorganism including a lot of prokaryote species where microbiota normoflora representatives are the main complex of extracorporeal physiological system acting as organism homeostasis regulator. When studying intermicrobial relations under microsymbiocenosis its system-forming factor has been identified that includes basic general functions of microorganisms - reproductive (growth/reproduction) and adaptive (biofilm formation and antilysozyme test). It has been shown that microbial interaction in dominant-associant vector providing microsymbiocenosis functioning is implemented via opposite (amplification/suppression) effect of reproductive and adaptive functions ofmicrosymbionts of dominant-associant pair contributing self-non-self discrimination. Intermicrobial discrimination of self-non-self microsymbionts goes before signaling of adaptive immunity of the host promoting microbe elimination or persistence in the body depending on the result of identification. It has been noted that microbial factor fulfilling the role oforganism homeostasis regulator performs synergistic functioning of dominant microflora with the host. When penetrating foreign associants (pathogens) into the organism host defense is implemented by means of induction of its adaptive immunity via cytokine reticulum. Key players of human intestinal microbiota are Bifidobacteria which along with induction of adaptive immunity and balance changes of pro- and anti-inflammatory cytokines of the host directly regulate microsymbiocenosis including system of hormones and neurotransmitters.