A core genome-based phylogenomic analysis of representative strains of the species Limosilactobacillus reuteri identified eight lineages that differ from the six previously described L. reuteri subspecies. Four of them are represented by isolates obtained from intestinal digesta or faeces of rodents and primates, including strains LR77T and LR80 (lineage X), mlc3T and LR92 (lineage VIII), LR51T and LR88 (lineage VII) and LR66T and LR52 (lineage IX). Analyses of pairwise average nucleotide identity and digital DNA-DNA hybridization values further support their genetic divergence from existing L. reuteri subspecies. These findings suggest the classification of these four lineages as one novel species of Limosilactobacillus and three new subspecies of L. reuteri. Therefore, we propose the novel species Limosilactobacillus secundus sp. nov. (type strain LR77T=DSM 113335T=LMG 32469T) and the novel subspecies L. reuteri subsp. pararodentium subsp. nov. (type strain mlc3T=DSM 113337T=LMG 32470T), L. reuteri subsp. peregrinus subsp. nov. (type strain LR51T=DSM 113336T=LMG 32467T) and L. reuteri subsp. simiae subsp. nov. (type strain LR66T=DSM 113334T=LMG 32468T). This expanded taxonomic framework enhances our understanding of the genetic diversity of L. reuteri and further supports its adaptations to diverse vertebrate hosts.
Li et al. (Fri,) studied this question.