lactobacillus

noun

lac·​to·​ba·​cil·​lus ˌlak-tō-bə-ˈsi-ləs 

: any of a genus (Lactobacillus) of bacteria that produce lactic acid

Examples of lactobacillus in a Sentence

Recent Examples on the Web

To keep things balanced, the formula also includes lactobacillus ferment, a postbiotic that supports a healthy skin microbiome—key for maintaining a strong barrier, especially if your skin tends to be reactive or sensitive. —Christa Joanna Lee, Allure, 3 July 2025

Identifying higher levels of healthy lactobacillus in the guts of people engaging in good anti-stress behaviors. —John Werner, Forbes.com, 13 June 2025

The true star ingredient of this formula is lactobacillus—a probiotic extract that helps repair the microbiome to rapidly calm redness and irritation. —Conçetta Ciarlo, Vogue, 13 June 2025

In healthy women without bacterial vaginosis, lactobacillus crispatus is the dominant bacteria and in those in a dysbiotic state there’s less lactobacillus crispatus and a more diverse microbiota, including bacteria like gardnerella vaginalis. —Sara Novak, Discover Magazine, 12 June 2024

Word History

Etymology

New Latin

First Known Use

1924, in the meaning defined above

Rhymes for lactobacillus

• amaryllis
• haemophilus
• bacillus
• utilise
• hilus
• villous
• villus
• willis

Medical Definition

lactobacillus

noun

lac·​to·​ba·​cil·​lus ˌlak-tō-bə-ˈsil-əs 

1

capitalized : a genus of gram-positive nonmotile lactic-acid-forming bacteria of the family Lactobacillaceae including various commercially important lactic acid bacteria

2

plural lactobacilli

-ˌī also -ˌē

: any bacterium of the genus Lactobacillus