Performance comparison of fecal preservative and stock solutions for gut microbiome storage at room temperature

The gut microbiome, which is symbiotic within the human body, assists in human digestion. It plays significant roles in identifying intestinal disease as well as in maintaining a healthy body with functional immune and metabolic activities. To confirm the consistency of fecal intestinal microbial research, it is necessary to study the changes in intestinal microbial flora according to the fecal collection solution and storage period. We collected fecal samples from three healthy Korean adults. To examine the efficacy of fecal collection solution, we used NBgene-Gut, OMNIgene-Gut, 70% ethanol (Ethanol-70%), and RNAlater. The samples were stored for up to two months at room temperature using three different methods, and we observed changes in microbial communities over time. We analyzed clusters of changes in the microbial flora by observing fecal stock solutions and metagenome sequencing performed over time. In particular, we confirmed the profiling of alpha and beta diversity and microbial classification according to the differences in intestinal environment among individuals. We also confirmed that the microbial profile remained stable for two months and that the microbial profile did not change significantly over time. In addition, our results suggest the possibility of verifying microbial profiling even for long-term storage of a single sample. In conclusion, collecting fecal samples using a stock solution rather than freezing feces seems to be relatively reproducible and stable for GUT metagenome analysis. Therefore, stock solution tubes in intestinal microbial research can be used without problems.