Porphyromonas gingivalis

The oral microbiome of periodontitis patients has distinct profiles dependent on disease severity

A few weeks ago we discussed periodontitis, a bacterial infection of the gums that leads to inflammation and deep pockets to develop in which harmful bacteria can colonize. Periodontitis develops in association with dramatic changes in the makeup of the oral microbiome. Smokers and diabetics are more frequently victims of the disease. The study we discussed previously was one performed by researchers in Istanbul, Turkey in which they tested whether a probiotic lozenge could improve the patients’ condition. In a different, more recently published study concerning periodontitis, researchers in Connecticut and Massachusetts looked not to change the oral microbiome of patients suffering from periodontitis, but to organize and identify the microbial characteristics of the disease.

In the study published in Plos One, seventeen subjects, 8 of whom were diabetic, with Chronic Kidney Disease (CKD) and seventeen subjects without CKD, 3 of whom were diabetic, were studied.  All 34 subjects suffered from periodontitis. Samples were taken from each participant, from the deepest pockets in two different areas of the mouth. DNA was then isolated and sequenced to identify microbial communities in each individual. After much statistical analysis, the researchers found that the microbial communities tended toward two clusters, A and B, with type B communities correlating with more severe periodontitis. Group A subjects had communities with greater health-associated bacteria and cluster B communities were dominated by Porphyromonas gingivalis and Tannerella forsythia. Additionally, the analysis showed that diabetes and CKD are not correlated with a certain periodontitis microbial makeup.

A set-back of this experiment is the low sample size, which makes for less meaningful statistical analysis. Greater sample sizes of each cluster could give stronger claim to the findings of this study. However, this study does begin to clarify the bacterial community characterization of healthy, unhealthy, and severely unhealthy oral microbiomes. In addition, the results from this study could be used to ask further questions about the disease, including questions such as: what environmental factors cause the difference in clusters A and B? Do inflammatory diseases such as CKD and diabetes have anything to do with the severity of inflammatory response of periodontitis? Further analysis may allow us to answer these tough questions.

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