The genus Lactobacillus has been split into 25 new genera

The genus Lactobacillus has been split into 25 new genera

The genus Lactobacillus is considered one of the most important living organisms to have influenced the planet throughout its evolutionary history (Lloyd, 2009). It was known that this bacterial genus was too large with 265 species described to date and with great important functions in our lives, ranging from food fermentation to their ability to benefit health in their human and animal host. That is why scientist have been using smaller functionally relevant entities (called phylogroups) within the genus.

Starting from these phylogroups a multidisciplinary group of scientists have reevaluated the complete taxonomy of Lactobacillus genus. This reevaluation has included core genome phylogeny, pairwise average amino acid identity, clade-specific signature genes, physiological criteria and the ecology of the organisms.

Based on this polyphasic approach, the genus Lactobacillus has been reclassified into 25 genera, including 23 novel genera. One genus keeps the old name ”Lactobacillus” while others got one of the novel genus names such as Secundilactobacillus, Liquorilactobacillus or Lactiplantibacillus. Thus, some probiotic Lactobacillus have not changed the name, such as Lactobacillus acidophilus, while others such as Lacticaseibacillus rhamnosus (formerly Lactobacillus rhamnosus) or Lacticaseibacillus casei (formerly Lactobacillus casei) have got new names. Notice that while genus names have changed in some cases, the parts of the names that indicate species were not changed. In addition, many new genus names were deliberately chosen to begin with the letter ‘L’, therefore most of the commercially available products will remain easy to recognize.

The new classification has been accepted for publication in the official journal of record for bacterial names and accordingly with, important institutions such as EFSA, Health Canada and the FDA have confirmed they will use the new names in their literature and communications, including the QPS list.

A range of completely new names can be extremely confusing and due to the importance of Lactobacillus genus for both scientist and industry, a web tool to figuring out the new name has been developed:  Check your favorite species!


What does it mean?

  • New publications on Lactobacillus strains should use the new genus
  • When searching the scienti­fic literature for a speci­fic strain, it may be necessary to search under both the old genus name and the new genus name.
  • New names of strains will have to be used on all product labels, legal and technical documentation, and other communications to consumers, the scientific community and medical professionals.


More information:

A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. Zheng J, Wittouck S, Salvetti E, Franz CMAP, Harris HMB, Mattarelli P, O’Toole PW, Pot B, Vandamme P, Walter J, Watanabe K, Wuyts S, Felis GE, Gänzle MG, Lebeer S. Int J Syst Evol Microbiol. 2020 Apr 15. doi: 10.1099/ijsem.0.004107.

International scientific association for probiotics and prebiotics. ISAPP Science Blog:

International scientific association for probiotics and prebiotics. ISAPP News: