Long-Term Stability of Oral Microbiome Samples

The human microbiome (i.e., the collection of microbial genes found in and on the human body) has been observed to be associated with numerous health conditions, but current methodological studies suggest that collection method, laboratory handling, bioinformatic processing of the data, and other factors can greatly affect microbiome study findings. In cohort studies, samples are typically collected at baseline, but are often not processed until sufficient cases have accumulated. This type of study design will require that samples remain frozen for likely many years prior to laboratory handling for microbiome measurements. To our knowledge, no study has considered the impact of long term storage of oral samples on oral microbiome characteristics. Therefore, we will evaluate the effect of long term storage of two oral sample collection methods (OMNIgene ORAL and Scope mouthwash) from 30 individuals who work at the NCI on oral microbiome characteristics. We will request that each participant will provide samples on 6 separate days over the course of two weeks. Participants will also fill out a short questionnaire. We will create aliquots from the pooled OMNIgene ORAL and Scope mouthwash samples from each individual, and immediately extract the DNA one aliquot. The remaining aliquots will be frozen at -80 degrees C and DNA will be extracted after one month, three months, six months, and one year after collection. The remaining aliquots will remain in the -80 degress C freezer for even longer term testing and other future studies. We will compare the microbial profiles from the stored samples to the immediately extracted samples to determine the effect of storage on oral samples.