Antimicrobial drugs that target human--not microbial--genotypes or phenotypes: a paradigm change in human evolutionary response to pathogen selection pressure.

Conventional antimicrobial drugs that target microbial life processes impose a selection pressure on pathogens and attenuate pathogen imposed selection pressure on human hosts. The simultaneous increase and decrease that result in pathogen and human host evolvability/adaptability, respectively, distorts the natural Darwinian evolutionary process. Such drugs may create an aberrant Darwinian genotype in human hosts that is ill prepared to resist emerging virulent pathogenic strains in the event of a decrease in host ontogenic potential. In contrast, antimicrobial drugs that target host human genes exert a selective pressure both on the human genome (without population decimation) as well as on pathogenic microbes. Such drugs maintain the evolvability/adaptability of the host in tandem with that of the pathogens in the context of Darwinian evolution. Such drugs retain the capacity of the human host to evolve genotypes that may confer resistance to future pathogenic microbial strains, to assimilate prokaryotic endosymbionts and to increase the probability of survival in the event of a decrease in host ontogenic potential.