Environment is shown to play a much more significant role in the mouth's microbial set up than genes. The human mouth is a community bustling with microorganisms that live there. Little knowledge exists about what factors control which types that live there and which don't. In a new study published in Genome Research, investigators have discovered environment has a more controlling
stance on determining oral microbiota, an extremely important finding in the field of oral health. The oral microbiome starts forming as soon as a person is born. We see a plethora of bacteria brought into our mouth during childhood and as an adult, although little knowledge is known about whether nature (genes), or nurture (environment) has a more powerful influence. Due to differences in the oral microbiome in health and diseases such as bacteremia and endicarditis, there is a need for a better understanding of the factors that effect oral microbiota communities, in order for more efficient prevention and treatment plans. During this study, the researchers sequenced the microbial DNA found in saliva samples of a group of twins, and then paired the DNA sequences in a database to see which types of bacteria existed in each individual. Comparing the salivary microbiomes of identical twins with the same genetic make-up and a common environment, the scientists found that their salivary microbiomes were not notably more similar than those of fraternal twins who only share half the genes. Surprisingly, this finding points to the idea that genetic relatedness is not such an important role. "We were also intrigued to see that the microbiota of twin pairs becomes less similar once they moved apart from each other," added Simone Stahringer, first author of the study. It was also seen from samples over time that the salivary microbiome changed the most during adolescence, suggesting behavioral changes or puberty may have a significant influence. The researchers also uncovered another surprising find, that there is a fundamental community of bacteria that exists in all humans. Ken Krauter, senior author of the study, explains: "Though there are definitely differences among different people, there is a relatively high degree of sharing similar microbial species in all human mouths." The authors believe that this study has provided a framework for future studies of the factors that control oral microbial communities. With this knowledge, people can now better understand how oral hygiene, environmental subjection to substances, methamphetamines, and even food can impact these microbes. 