A comparison of metabarcoding analysis between ASVs and OTUs - using data regarding the effects of chronic radiation on the bank vole gut microbiota

Abstract

The gut microbiome is dynamic within its host and susceptible to changes in both diversity and functionality. A variety of environmental factors can disturb the balance of the gut microbiome, including chronic environmental radiation. It has been previously documented that exposure to chronic levels of radiation can induce changes in the gut microbiome in a time-dependent manner. Bank voles from the area in and around the Chernobyl Exclusion Zone provide an ideal model for examining the effects of chronic environmental radiation on the gut microbiome. Past studies on these subjects have been conducted through Operational Taxonomic Unit (OTU) based metabarcoding analysis, which works on the basis of clustering according to sequence similarity. Notably, a newer Amplicon Sequence Variant (ASV) based method of metabarcoding analysis is rapidly increasing in popularity for conducting such analyses. This is in large part due to its capacity for specific single nucleotide differentiation and identification of microbial gene sequences at a species level. Herein, we conduct a direct comparison of these two metabarcoding analysis methods for identifying the effects of chronic radiation on the gut microbiome of bank voles. Our results suggest that while OTU and ASV metabarcoding analyses yield similar results with regard to examining microbial diversity and functionality, ASV-based analysis is able to capture slightly more detailed gut microbial diversity compared to OTU-based analysis.