A clinically validated human saliva metatranscriptomic test for global systems biology studies

The authors report here the development of a high-throughput, automated, inexpensive and clinically validated saliva metatranscriptome test that requires less than 100 μl of saliva. RNA is preserved at the time of sample collection, allowing for ambient-temperature transportation and storage for up to 28 days. Critically, the RNA preservative is also able to inactivate pathogenic microorganisms, rendering the samples noninfectious and allowing for safe and easy shipping. Given the unique set of convenience, low cost, safety and technical performance, this saliva metatranscriptomic test can be integrated into longitudinal, global-scale systems biology studies that will lead to an accelerated development of precision medicine, diagnostic and therapeutic tools. This paper introduces a novel method for the preservation and metatranscriptomic analysis of low volumes of saliva. The method involves mixing saliva with a preservative at the time of sample collection, isolating RNA, depleting rRNAs from the sample and converting the RNA into directional, dual-barcoded libraries for sequencing. This method can be used for the analysis of microbial species, Kyoto Encyclopedia of Genes and Genomes orthologs and human genes present in saliva.