Abstract: Every human body has many microbial communities, there are certain group of microbial communities called as the oral microbial community, these microbiomesare healthy unless and until they are triggered by certain environmental factors that enable them to produce disease. The microbes are being identified and sequenced by certain methods such as DNA hybridization and the PCR techniques and these microbes are found to be specific at specific siteswhich are given by site specialist hypothesis and it is also found that specific microbes are for specific persons hence it can help with the concept of the personalised medicine. It is found in recent years that tolerance to these microbes can also be developed to the foetus prenatally itself with the help of the mother’s microbiome.