Table 1 Strains and characteristics of the NIBSC Gut-Mix-RR and Gut-HiLo-RR. Gut-Mix-RR percentage is based on relative number of genome copies. Gut-HiLo-RR percentage is based on relative number of genome copies. GC content based on genome sequences where available or if not available (*) by the original species description. Accession numbers are GenBank Accession numbers or RefSeq accession numbers if available. NC_008530 is the RefSeq accession for the type strain Lactobacillus gasseri ATCC 33323. Sequences generated from this study for all strains are available from NCBI Bioproject ID PRJNA622674. 16S rRNA copy number and intragenomic variation is based on analysis of genome sequences through IMG/M