The reductionism and Manichaean view of the microbe?human host relationship are the two major limitations in the conventional theories of microbial infection. Three focal point theory-based game models (pure cooperative, dilemma and pure conflict) are proposed for resolving those problems. There exists a dynamic duality relationship (DDR) between symbiosis (Sym) and pathogenesis (Pat) in microbial infection, which is the most fundamental problem in infectomics. Our health is associated with the dynamic interactions of three microbial communities [nonpathogenic microbiota (NP) (Cooperation), conditional pathogens (CP) (Dilemma), and unconditional pathogens (UP) (Conflict)] with the hosts at three different health statuses [nonsusceptibility (NS), conditional susceptibility (CS), and unconditional susceptibility (US)]. Sym and Pat can be quantitated by measuring symbiotic index ( SI), which is quantitative fitness for the symbiotic partnership, and pathogenic index ( PI), which is quantitative damage to the symbiotic partnership, respectively. The values of SI and PI can be used for calculation of the symbiotic point (SP).