Comment: Your mouth is home to a thriving community of microbial life. More than 600 different species of bacteria reside in this “microbiome,” yet everyone hosts a unique set of bugs, and this could have important implications for health and disease. The human body harbours ten times more bacterial cells than human cells – a stunning figure that suggests a likely dynamic between ourselves and the bacteria we carry, both in healthy and disease states.
The National Institutes of Health recently launched an initiative to categorize the microbiomes of several regions of the body, with early studies focusing on the intestines and skin. It is appreciated that the human mouth, a major entry point for bacteria into the body, also contains a diverse array of microbial species. Yet microbiome diversity between individuals, and how this relates to diet, environment, health, and disease, remains unexplored.
The group observed that there is considerable diversity of bacterial life in the saliva microbiome, both within and between individuals. However, they made an unexpected finding when comparing samples from different geographic areas. “The saliva microbiome does not vary substantially around the world,” Stoneking described. “Which seems surprising given the large diversity in diet and other cultural factors that could influence the human salivary microbiome.” Stoneking explained that this suggests the life inhabiting the mouth of your next-door neighbour is likely to be just as different from yours as someone on the other side of the world.
Nasidze, I., Li, J., Quinque, D., Tang, K., and Stoneking, M. Global diversity in the human salivary microbiome. Genome Res. doi:10.1101/gr.084616.108 View Abstract
