The new situation will facilitate the more comprehensive understanding of the importance of the lactobacilli and a more detailed and reliable communication.

For maintenance of continuity within the QPS list, all the strains belonging to a previous designed Lactobacillus species will be transferred to the new species. Both the previous and new names will be retained and are included in the QPS list.

 Background. On April 15 2020 the nomenclature of the genus Lactobacillus, together with some other related taxa like the pediococci, leuconostocs, fructobacilli, etc was revisited and the single genus split into 25 genera. The genus Lactobacillus has been divided into 25 new genera (Zheng et al., 2020). As a consequence, the 37 species that are considered as QPS were reclassified into 13 genera.

How did this happen? A team of 15 researchers from 12 different institutions and 7 countries was put together to apply whole genome analysis to analyze each Lactobacillus species. Their proposal, which was accepted for publication in the official journal of record for bacterial names, is that the species once contained within the Lactobacillus genus should now spread over 25 genera, including 23 novel genera (see paper link here).

To facilitate the conversion from old to new nomenclature, the team involved in this project has created a simple online tool to help with the conversion, which can be found at this link.

But even if some genus names have changed, the parts of the names that indicate species were not: all new genera proposed for this group begin with the letter “L”, so  the ‘L.’ genus abbreviation may still be used.

This was also summarized by ISAPP in this useful infographic. 

What happens now?

The 37 species that are considered as QPS became classified into 13 genera, of which 10 species are now included in the new genus Lactobacillus (homonym to the previous genus appellation), five belong to the genus Limosilactobacillus, four to Lentilactobacillus, three to each of Ligilactobacillus, Lacticaseibacillus and Lactiplantibacillus, two to Companilactobacillus and Latilactobacillus and one to each of the genera Levilactobacillus, Secundilactobacillus, Loigolactobacillus, Fructilactobacillus and Lapidilactobacillus. EFSA has published a table to clarify the correspondence between the previous and new designations of the QPS species, following the alphabetical order of their specific names (it can be found in the EFSA publication, Chapter 3.4).

A full transition from old to new nomenclature will take time, probably years. Consumers and administrators at this point need to get used to the new names appearing on the labels of foods and food supplements, and researchers and regulators too will need to be re-educated and start to use the new names.

To maintain continuity within the QPS list, all the strains belonging to a previous designed Lactobacillus species will be transferred to the new species. Both the previous and new names will be retained.