Initial storage impacts taxonomic profile in metaproteomics study of human stool

With the technological advances of the last decade, it is now feasible to analyze environmental samples of vast complexity, such as human stool specimen, using meta-omics techniques like metaproteomics. Still the most sophisticated, sensitive instruments can only extract information that a sample contains in the first place. This highlights the need for initial sample preparation to preserve as much unaltered information as possible. Yet little is known about the effects different processing approaches have on the final analysis results. This study analyzes human stool samples applying metaproteomics and shows that the initial sample storage has a massive effect on the taxonomic composition of proteins identified. The findings are backed up by the results of the metagenomics analysis of the same samples. This suggests, that great care should be taken in choosing storage conditions for (omics) studies, as well as in comparing the results of experiments with different initial processing.