Total RNA Sequencing reveals microbial communities in human blood and disease specific effects
Authors: Serghei Mangul, Loes M Olde Loohuis, Anil P Ori, Guillaume Jospin, David Koslicki, Harry Taegyun Yang, Timothy Wu, Marco P Boks, Catherine Lomen-Hoerth, Martina Wiedau-Pazos, Rita M Cantor, Willem M de Vos,René S Kahn, Eleazar Eskin, Roel A Ophoff
Preprint posted in BioRxiv on June 7, 2016
COMMENT: In this preprint the authors demostrate the potential use of total RNA to study microbes that inhabit the blood.
They analyze the unmapped reads of RNA-Seq of whole blood from 192 individuals and are able to detect bacteria and archaea in all the blood samples. Then, they study the differences in the composition of microbial communities present in blood from four subject groups: schizophrenia, amyotrophic lateral sclerosis, bipolar disorder, and healthy controls. They used Phylosift (Darling et al. 2014) to perform phylogenetic and taxonomic analyses of the whole blood samples and compare across individuals.
They include a special section entitled "Validation and potential contamination" in which they perform a negative control experiment with RNA-Seq reads from six B-lymphoblast cell line (LCLs) samples that are expected to be sterile.
This is another work demostrating that the blood is not a sterile environment and that the blood microbiome exists in all the individuals. Considering that blood is the sample most used in medicine I think that the use of the blood microbiome as biomarker can reshape the clinical applications of the microbiome. Easy to obtain in clinical environments, cleaner than other microbiomes, and probably more stable than gut microbiome and hence, better to design reliable tests.