One of the most important groups of probiotic bacteria – both in terms of their impact on human health and for their economic significance – are the Lactobacilli. These are the ones you especially find in yogurts and yogurt drinks that heavily advertise their probiotic virtues.

The Lactobacillus genus is one of oldest known groups of bacteria, and the first species was named in the early 1900s. More recently, the genus has been called one of the most significant on the planet, because of its impact on human health and societal development through its role in innovations like food fermentation.

As of March 2020, over 250 species belonged to the genus Lactobacillus – and this has started to cause problems for scientists, who note that there is a wide diversity of form and function among the group, which is not apparent from the extensive use of the Lactobacillus name. We need a simple way of telling these species apart.

To address these issues, and to tidy up the scientific record, the authors of a new study in the International Journal of Systematic and Evolutionary Microbiology have analysed the genome of every existing Lactobacillus species, and they now propose that these species constitute 25 distinct genera. The new groupings make more intuitive sense, with bacteria serving similar functions now classified together.

The new naming system might eventually have an impact on probiotic food labelling, which may need to get a lot more specific about which species are present. Luckily, the researchers have provided a handy web tool that can be used to find the new names of species.