Purpose of the study The human gut microbiome has been linked to many human diseases, with a growing interest in the influence it might have on the development of colorectal cancer. The aim of this study was to investigate the feasibility of using the National Health Service Bowel Screening Programme (NHSBCSP) guaiac faecal occult blood test (gFOBt) cards for microbial analysis by profiling matched gFOBt and fresh stool samples. We also explored whether the long term storage of gFOBt cards had a detrimental effect on microbiome analysis. Methods Three healthy volunteers each provided three separate fresh stool samples. These samples were applied to gFOBt cards, and the microbial DNA was isolated from the paired fresh stool and gFOBt card samples. We also examined the stability of microbiome extract in fresh stool samples on gFOBt cards stored at room temperature over a period of 2 weeks to 2 years. The V4 region of the 16srRNA gene was amplified, and libraries sequenced on an Illumina MiSeq. Data was analysed using the QIIME software. Results Between 16971 and 85790 reads per sample were obtained (median 44685). Samples were grouped both by volunteer, and by sample type (fresh or gFOBt). Groups were compared in a variety of ways: visual inspection of taxa, within sample beta diversity, principle component analysis and t-tests of weighted and unweighted UniFrac distances. By all methods, samples grouped by volunteer and not by sample type. Analysis of the different time points showed no appreciable differences with increased storage time. Conclusions This study identified good concordance between microbial DNA isolated from gFOBt and fresh stool samples. Samples stored over 2 years showed no detrimental changes in the bacteria identified. This study has important implications for the ease of performing large scale microbiome studies, and the potential for future population or patient screening for colorectal cancer and other pathologies.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)