A new long-term study of human twins by University of
Colorado Boulder researchers indicates the makeup of the population of bacteria
bathing in their saliva is driven more by environmental factors than
heritability.
The study compares saliva samples from identical and
fraternal twins to see how much “bacterial communities” in saliva vary from
mouth to mouth at different points in time, said study leader and CU-Boulder
Professor Kenneth Krauter. The twin studies show that the environment, rather
than a person’s genetic background, is more important in determining the types
of microbes that live in the mouth.