Fig. 1

Sequencing technical accuracy verification. a Composition of a mock community consisting of 8 different bacterial species with a known composition was assessed (n = 8 per batch). The mock community used contained Escherichia coli and Salmonella enterica; which cannot be resolved using 16S rRNA gene sequencing [11]. We considered the relative abundance of unclassified Enterobacteriaceae as a surrogate for the cumulative relative abundance of these two species. b Taxonomic composition of biological controls was compared. Biological controls comprised of 9 samples originally extracted and sequenced in batch 1 that were re-sequenced in batch 2. Top 5 abundant ASVs per sample are visualised. c Prevalence and d relative abundance of all present ASVs (N = 2192) in biological controls were compared between batches. Each dot represents the average per batch. There is high agreement and consistency in the ASVs prevalence and relative abundance between the batches. Given the small sample size of biological controls, we did not identify potential reagent contaminants using the biological controls. The solid red line represents a perfect correlation. The dotted line shows the linear association between average relative abundance values of batches. ASV, amplicon sequencing variant; ICC, intraclass correlation coefficient