Evaluation of sampling and storage procedures on preserving the community structure of stool microbiota: A simple at-home toilet-paper collection method.

BACKGROUND: The increasing interest on the impact of the gut microbiota on health and disease has resulted in multiple human microbiome-related studies emerging. However, multiple sampling methods are being used, making cross-comparison of results difficult. To avoid additional clinic visits and increase patient recruitment to these studies, there is the potential to utilize at-home stool sampling. The aim of this pilot study was to compare simple self-sampling collection and storage methods.

METHODS: To simulate storage conditions, stool samples from three volunteers were freshly collected, placed on toilet tissue, and stored at four temperatures (-80, 7, 22 and 37°C), either dry or in the presence of a stabilization agent (RNAlater®) for 3 or 7days. Using 16S rRNA gene sequencing by Illumina, the effect of storage variations for each sample was compared to a reference community from fresh, unstored counterparts. Fastq files may be accessed in the NCBI Sequence Read Archive: Bioproject ID PRJNA418287.

RESULTS: Microbial diversity and composition were not significantly altered by any storage method. Samples were always separable based on participant, regardless of storage method suggesting there was no need for sample preservation by a stabilization agent.

DISCUSSION: In summary, if immediate sample processing is not feasible, short term storage of unpreserved stool samples on toilet paper offers a reliable way to assess the microbiota composition by 16S rRNA gene sequencing.