High stability of faecal microbiome composition in guanidine thiocyanate solution at room temperature and robustness during colonoscopy

We read with interest the paper by Jalanka et al,1 who examined the influence of bowel preparation on intestinal microbiota by using phylogenetic microarray and quantitative PCR analyses of frozen samples. Conventionally, faecal samples are frozen on dry ice or in a deep-freezer (at –80°C) immediately after collection, as done by Jalanka et al, because bacterial taxa can change appreciably within 15 min at room temperature (RT).2 However, immediate deep-freezing is often inconvenient in routine clinical practice, and we wondered whether simple storage of faecal samples at RT in test tubes containing 4 M guanidine thiocyanate solution would be equally effective. Guanidine thiocyanate is a general protein denaturant3 and inhibits bacterial growth.3–5 We collected faecal samples before and after colonoscopy, and divided each into two parts: one was stored frozen and the other at RT. Taxonomic compositions were determined...

Source: Gut - August 8, 2016 Category: Gastroenterology Authors: Nishimoto, Y., Mizutani, S., Nakajima, T., Hosoda, F., Watanabe, H., Saito, Y., Shibata, T., Yachida, S., Yamada, T. Tags: Open access PostScript Source Type: research