Table 4 Comparison of the microbiome storage studies carried out since 2014

1

72 h

Comparison of OMNIgene·GUT/ RNA later/ Tris-EDTA buffer storage methods

MoBio Powelyser Powersoil DNA Isolation Kit

Illumina MiSeq 16S rRNA

Least alteration from OMNIgene·GUT

[25]

3

3 days

Comparison of RNAlater storage at RT for 3 days vs. storage at -80 °C

MO BIO Powelyser Powersoil DNA isolation kit

454 sequencing of 16S rRNA

RNAlater tend to show lower diversity and purity

[24]

18 (IBS-IBD patients + controls)

24 h

Comparison between storage at RT for 24 h/ storage at + 4 °C for 24 h/ storage at -20 °C for one week vs. storage at -80 °C

PSP lysis buffer+ beat-beating+ PSP Spin stool kit

454 sequencing of 16S RNA + qPCR on Methanobrevibacter smithii

No significant differences between the storage at RT for 24 h, storage at 4 °C for 24 h and storage at -20 °C for one week.

[23]

4

15 or 30 min

Comparison between storage at RT for 15 min vs. 30 min vs. no buffer

Qiagen stool Mini kit+ Bead-beating

qPCR

Fecal samples should be frozen within 15 min counting from collection.

[22]

41 (19 elderly + 22 infants)

7 or 14 days

Storage at RT within OMNIgene·GUT kit for 7 or 14 days vs. fresh samples

RBB

Ilumina MiSeq + PicoGreen

OMNIgene·GUT kit did not significantly impact microbiota composition and diversity in elderly datasets after 7d of storage. It can be used instead of fresh method.

[13]

14

24 h and 7 days

Comparison of storage at RT within OMNIgene·GUT for 24 h or 7 days vs freezing + comparison of two DNA extraction method

MO BIO Power Fecal DNA Isolation Kit vs. Qiagen QIAmp DNA Stool Mini kit+ bead-beating

Illumina MiSeq 16S RNA + qPCR on Bacteroides spp., Bifidobacterium spp. and Clostriduim cluster IV

Significant influence of DNA extraction method + no influence of storage within OMNIgene·GUT and between OMNIgene·GUT vs. Fresh in terms of microbial diversity and quantity

Our study