# Lactobacillus (and its successor genera)

Lactobacillus is a group of Gram-positive bacteria. They make lactic acid. You meet them in fermented foods and probiotics. In 2020, Zheng and colleagues reorganized the genus. They used whole-genome family trees. They split it into 25 separate genera. The name Lactobacillus was kept for just one group, the L. delbrueckii clade. New names came in for the rest. L. plantarum became Lactiplantibacillus. L. reuteri became Limosilactobacillus. L. casei and rhamnosus became Lacticaseibacillus. People still say 'lactobacilli' for the broader family. One key point: benefits are strain-specific. Some strains help with antibiotic-associated diarrhea. Some help with infectious gastroenteritis or vaginal flora. But the genus as a whole is not a proven remedy.

## Sources

- Zheng J, Wittouck S, Salvetti E, et al.. (2020). 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. International Journal of Systematic and Evolutionary Microbiology. https://doi.org/10.1099/ijsem.0.004107
- Hill C, Guarner F, Reid G, et al.. (2014). The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology. https://doi.org/10.1038/nrgastro.2014.66

---

_Canonical: https://usa-longevity.com/en/glossary/lactobacillus · Part of Longevity Cities · Updated 2026-06-22_