Mikroorganizmalar ve insan vücudu ile olan etkileşimleri.

If we compare the number of human beings to the number of bacteria living on the earth at the same time, it appears a proportion as around 1/1018 in favor of bacteria. Analyzing the association of the human beings in relation with such a crowded community has become a necessity. However, studies have generally been focused on the noxious bacteria and non-noxious bacteria have been ignored. This circumstance has been provided a variety of achievements including full recovery of the infection diseases. During the same period, chronical diseases have been increased at a great pace (dramatically) and even remission has been accepted to be quite an achievement. It is expected that, especially, particular etiopathogenesis of chronical diseases being associated with hypothesis and not clarified implicitly can be grounded on that, the factors inducing the diseases are not appear enough and some of them are even disregarded. Possibly, the missing point is that, the pathogens were majored on and non-pathogen bacteria's relation with human beings has not been analyzed sufficiently. Attending to this point, increasing studies faced to a big problem: how can the human body discriminate the bacteria, most of them have surface antigens, as pathogen or non-pathogen? In this review, pathogen microorganisms, flora and their relation with human beings have been attempted to consider and three major hypotheses about host discrimination between pathogens and non-pathogens have been intended to explain. [ABSTRACT FROM AUTHOR]